{ "results": [{"id":"19236","title":"Internal solitons in the ocean and their effect on underwater sound","abstract":"Nonlinear internal waves in the ocean are discussed (a) from the standpoint of soliton theory and (b) from the viewpoint of experimental measurements. First, theoretical models for internal solitary waves in the ocean are briefly described. Various nonlinear analytical solutions are treated, commencing with the well-known Boussinesq and Korteweg\u2013de Vries equations. Then certain generalizations are considered, including effects of cubic nonlinearity, Earth\u2019s rotation, cylindrical divergence, dissipation, shear flows, and others. Recent theoretical models for strongly nonlinear internal waves are outlined. Second, examples of experimental evidence for the existence of solitons in the upper ocean are presented; the data include radar and optical images and in situ measurements of wave forms, propagation speeds, and dispersion characteristics. Third, and finally, action of internal solitons on sound wave propagation is discussed. This review paper is intended for researchers from diverse backgrounds, including acousticians, who may not be familiar in detail with soliton theory. Thus, it includes an outline of the basics of soliton theory. At the same time, recent theoretical and observational results are described which can also make this review useful for mainstream oceanographers and theoreticians.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"121","number":"2","pagerange":"695-722","doi":"10.1121\/1.2395914","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5820","last_name":"Apel","first_name":"","first_name_abbr":"J. R.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5821","last_name":"Ostrovsky","first_name":"","first_name_abbr":"L. A.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"4","short_name":"PSD3","type":"Contractor"},{"creator_id":"5822","last_name":"Stepanyants","first_name":"","first_name_abbr":"Y. A.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19237","title":"Rates of thermohaline recovery from freshwater pulses in Modern, Last Glacial Maximum and Greenhouse Warming Climates","abstract":"Recovery rates of the thermohaline circulation after a freshwater pulse in the North Atlantic vary considerably depending on the background climate, as demonstrated in the Community Climate System Model. The recovery is slowest in a Last Glacial Maximum (LGM) climate, fastest in a modern climate, and intermediate between the two in a greenhouse warming (4XCO2) climate. Previously proposed mechanisms to explain thermohaline circulation stability involving altered horizontal freshwater transport in the North Atlantic are consistent with relative recovery rates in the modern and 4XCO2 climates, but fail to explain the slow LGM recovery. Instead, sea ice expansion inhibits deep-water formation after freshening in the LGM climate by reducing heat loss to the atmosphere and providing additional surface freshwater. In addition, anomalous vertical freshwater transport across \u223c1 km depth after freshening is most effective at weakening the stratification in the modern case but is negligible in the LGM case.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L07708","doi":"10.1029\/2006GL029237","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5823","last_name":"Bitz","first_name":"","first_name_abbr":"C. M.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5824","last_name":"Chiang","first_name":"","first_name_abbr":"J. C. H.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5825","last_name":"Cheng","first_name":"","first_name_abbr":"W.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5340","last_name":"Barsugli","first_name":"","first_name_abbr":"J. J.","orcid":"","pos":"3","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19238","title":"Air\u2013Sea Exchange in Hurricanes: Synthesis of Observations from the Coupled Boundary Layer Air\u2013Sea Transfer Experiment","abstract":"The Coupled Boundary Layer Air\u2013Sea Transfer (CBLAST) field program, conducted from 2002 to 2004, has provided a wealth of new air\u2013sea interaction observations in hurricanes. The wind speed range for which turbulent momentum and moisture exchange coefficients have been derived based upon direct f lux measurements has been extended by 30% and 60%, respectively, from airborne observations in Hurricanes Fabian and Isabel in 2003. The drag coefficient (CD) values derived from CBLAST momentum flux measurements show CD becoming invariant with wind speed near a 23 m s\u22121 threshold rather than a hurricane-force threshold near 33 m s\u22121. Values above 23 m s\u22121 are lower than previous open-ocean measurements.\r\n\r\nThe Dalton number estimates (CE) derived from CBLAST moisture flux measurements are shown to be invariant with wind speeds up to 30 m s\u22121, which is in approximate agreement with previous measurements at lower winds. These observations imply a CE\/CD ratio of approximately 0.7, suggesting that additional energy sources are necessary for hurricanes to achieve their maximum potential intensity. One such additional mechanism for augmented moisture flux in the boundary layer might be \u201croll vortex\u201d or linear coherent features, observed by CBLAST 2002 measurements to have wavelengths of 0.9\u20131.2 km. Linear features of the same wavelength range were observed in nearly concurrent RADARSAT Synthetic Aperture Radar (SAR) imagery.\r\n\r\nAs a complement to the aircraft measurement program, arrays of drifting buoys and subsurface floats were successfully deployed ahead of Hurricanes Fabian (2003) and Frances (2004) [16 (6) and 38 (14) drifters (floats), respectively, in the two storms]. An unprecedented set of observations was obtained, providing a four-dimensional view of the ocean response to a hurricane for the first time ever. Two types of surface drifters and three types of floats provided observations of surface and sub-surface oceanic currents, temperature, salinity, gas exchange, bubble concentrations, and surface wave spectra to a depth of 200 m on a continuous basis before, during, and after storm passage, as well as surface atmospheric observations of wind speed (via acoustic hydrophone) and direction, rain rate, and pressure. Float observations in Frances (2004) indicated a deepening of the mixed layer from 40 to 120 m in approximately 8 h, with a corresponding decrease in SST in the right-rear quadrant of 3.2\u00b0C in 11 h, roughly one-third of an inertial period. Strong inertial currents with a peak amplitude of 1.5 m s\u22121 were observed. Vertical structure showed that the critical Richardson number was reached sporadically during the mixed-layer deepening event, suggesting shear-induced mixing as a prominent mechanism during storm passage. Peak significant waves of 11 m were observed from the floats to complement the aircraft-measured directional wave spectra.\r\n","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"3","pagerange":"357-374","doi":"10.1175\/BAMS-88-3-357","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5826","last_name":"Black","first_name":"","first_name_abbr":"P. G.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5827","last_name":"D'Asaro","first_name":"","first_name_abbr":"E. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5828","last_name":"Drennan","first_name":"","first_name_abbr":"W. M.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5829","last_name":"French","first_name":"","first_name_abbr":"J. R.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5830","last_name":"Niiler","first_name":"","first_name_abbr":"P. P.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5831","last_name":"Sanford","first_name":"","first_name_abbr":"T. B.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5832","last_name":"Terrill","first_name":"","first_name_abbr":"E. J.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5509","last_name":"Walsh","first_name":"","first_name_abbr":"E. J.","orcid":"","pos":"7","branch_id":"23","staff_type_id":"5","short_name":"PSD3","type":"other"},{"creator_id":"5833","last_name":"Zhang","first_name":"","first_name_abbr":"J. A.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19239","title":"High resolution vertical distributions of NO3 and N2O5 through the nocturnal boundary layer","abstract":"The shallow mixing depth and vertical stratification of the lowest levels of the atmosphere at night has implications for the chemistry of nitrogen oxides emitted from the surface. Here we report vertical profiles of NO3, N2O5 and O3 measured from in-situ instruments on a movable carriage on a 300 m tower. The study offers high-resolution (<1 m) vertical distributions of both NO3 and N2O5 and shows that the nocturnal mixing ratios of these compounds vary widely over short vertical distance scales (10 m or less). Furthermore, there are systematic differences in the steady state lifetimes of NO3 and N2O5 and in the partitioning among nitrogen oxides between different near-surface layers. These differences imply that NO3 and N2O5 occupy distinct chemical regimes as a function of altitude, potentially serving as sinks for nitrogen oxides and O3 near the surface but as reservoirs of NOx and O3 aloft.","book_title":"","series":"","published_year":"2007","published_month":"1","publication":"Atmos. Chem. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"7","number":"","pagerange":"139-149","doi":"10.5194\/acp-7-139-2007","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5563","last_name":"Brown","first_name":"","first_name_abbr":"S. S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5564","last_name":"Dub\u00e9","first_name":"","first_name_abbr":"W. P.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5565","last_name":"Osthoff","first_name":"","first_name_abbr":"H. D.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5834","last_name":"Wolfe","first_name":"","first_name_abbr":"D. E.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5551","last_name":"Angevine","first_name":"","first_name_abbr":"W. M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5566","last_name":"Ravishankara","first_name":"","first_name_abbr":"A. R.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19240","title":"Investigating the Impact of Reemerging Sea Surface Temperature Anomalies on the Winter Atmospheric Circulation over the North Atlantic","abstract":"Extratropical SSTs can be influenced by the \u201creemergence mechanism,\u201d whereby thermal anomalies in the deep winter mixed layer persist at depth through summer and are then reentrained into the mixed layer in the following winter. The impact of reemergence in the North Atlantic Ocean (NAO) upon the climate system is investigated using an atmospheric general circulation model coupled to a mixed layer ocean\/thermodynamic sea ice model.\r\n\r\nThe dominant pattern of thermal anomalies below the mixed layer in summer in a 150-yr control integration is associated with the North Atlantic SST tripole forced by the NAO in the previous winter as indicated by singular value decomposition (SVD). To isolate the reemerging signal, two additional 60-member ensemble experiments were conducted in which temperature anomalies below 40 m obtained from the SVD analysis are added to or subtracted from the control integration. The reemerging signal, given by the mean difference between the two 60-member ensembles, causes the SST anomaly tripole to recur, beginning in fall, amplifying through January, and persisting through the following spring. The atmospheric response to these SST anomalies resembles the circulation that created them the previous winter but with reduced amplitude (10\u201320 m at 500 mb per \u00b0C), modestly enhancing the winter-to-winter persistence of the NAO. Changes in the transient eddies and their interactions with the mean flow contribute to the large-scale equivalent barotropic response throughout the troposphere. The latter can also be attributed to the change in occurrence of intrinsic weather regimes.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"14","pagerange":"3510-3526","doi":"10.1175\/JCLI4202.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5543","last_name":"Cassou","first_name":"","first_name_abbr":"C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5359","last_name":"Deser","first_name":"","first_name_abbr":"C.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5358","last_name":"Alexander","first_name":"","first_name_abbr":"M. A.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19241","title":"A New Look at Stratospheric Sudden Warmings Part II: Evaluation of Numerical Model Simulations","abstract":"The simulation of major midwinter stratospheric sudden warmings (SSWs) in six stratosphere-resolving general circulation models (GCMs) is examined. The GCMs are compared to a new climatology of SSWs, based on the dynamical characteristics of the events. First, the number, type, and temporal distribution of SSW events are evaluated. Most of the models show a lower frequency of SSW events than the climatology, which has a mean frequency of 6.0 SSWs per decade. Statistical tests show that three of the six models produce significantly fewer SSWs than the climatology, between 1.0 and 2.6 SSWs per decade. Second, four process-based diagnostics are calculated for all of the SSW events in each model. It is found that SSWs in the GCMs compare favorably with dynamical benchmarks for SSW established in the first part of the study.\r\n\r\nThese results indicate that GCMs are capable of quite accurately simulating the dynamics required to produce SSWs, but with lower frequency than the climatology. Further dynamical diagnostics hint that, in at least one case, this is due to a lack of meridional heat flux in the lower stratosphere. Even though the SSWs simulated by most GCMs are dynamically realistic when compared to the NCEP\u2013NCAR reanalysis, the reasons for the relative paucity of SSWs in GCMs remains an important and open question.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"3","pagerange":"470-488","doi":"10.1175\/JCLI3994.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5835","last_name":"Charlton","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5836","last_name":"Polvani","first_name":"","first_name_abbr":"L. M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5837","last_name":"Perlwitz","first_name":"","first_name_abbr":"J.","orcid":"0000-0003-4061-2442","pos":"2","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5838","last_name":"Sassi","first_name":"","first_name_abbr":"F.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5839","last_name":"Manzini","first_name":"","first_name_abbr":"E.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5840","last_name":"Shibata","first_name":"","first_name_abbr":"K.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5841","last_name":"Pawson","first_name":"","first_name_abbr":"S.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5842","last_name":"Nielsen","first_name":"","first_name_abbr":"J. E.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5843","last_name":"Rind","first_name":"","first_name_abbr":"D.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19242","title":"Boundary-layer dynamics and its influence on atmospheric chemistry at Summit, Greenland","abstract":"Sonic anemometer turbulence measurements were made at Summit, Greenland during summer 2004 and spring 2005. These measurements allow for the characterization of the variability of the atmospheric boundary layer at this site by describing seasonal and diurnal changes in sensible heat flux and boundary layer stability as well as providing estimates of mixing layer height. Diurnal sensible heat fluxes at Summit ranged from \u221218 to \u22122 W m\u22122 in the spring and from \u22127 to +10 W m\u22122 in the summer. Sustained stable surface layer conditions and low wind speeds occured during the spring but not during the summer months. Unstable conditions were not observed at Summit until late April. Diurnal cycles of convective conditions during the daytime (0700\u20131700 h local time) were observed throughout July and August. Boundary layer heights, which were estimated for neutral to stable conditions, averaged 156 m for the spring 2005 observations. Comparisons of the boundary layer characteristics of Summit with those from South Pole, Antarctica, provide possible explanations for the significant differences in snowpack and surface-layer chemistry between the two sites.","book_title":"","series":"","published_year":"2007","published_month":"8","publication":"Atmos. Environ.","publisher":"","pages":"0","place_of_pub":"","volume":"41","number":"24","pagerange":"5044-5060","doi":"10.1016\/j.atmosenv.2006.06.068","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5844","last_name":"Cohen","first_name":"","first_name_abbr":"L.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5845","last_name":"Helmig","first_name":"","first_name_abbr":"D.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5846","last_name":"Neff","first_name":"","first_name_abbr":"W. D.","orcid":"","pos":"2","branch_id":"3","staff_type_id":"1","short_name":"DO","type":"Federal"},{"creator_id":"5381","last_name":"Grachev","first_name":"","first_name_abbr":"A. A.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"}],"editors":[]},{"id":"19243","title":"An Intercomparison of Microphysical Retrieval Algorithms for Upper-Tropospheric Ice Clouds","abstract":"The large horizontal extent, with its location in the cold upper troposphere, and ice composition make cirrus clouds important modulators of the Earth's radiation budget and climate. Cirrus cloud microphysical properties are difficult to measure and model because they are inhomogeneous in nature and their ice crystal size distribution and habit are not well characterized. Accurate retrievals of cloud properties are crucial for improving the representation of cloud-scale processes in large-scale models and for accurately predicting the Earth's future climate. A number of passive and active remote sensing retrieval algorithms exist for estimating the microphysical properties of upper-tropospheric clouds. We believe significant progress has been made in the evolution of these retrieval algorithms in the last decade; however, there is room for improvement. Members of the Atmospheric Radiation Measurement (ARM) program Cloud Properties Working Group are involved in an intercomparison of optical depth (\u03c4) and ice water path in ice clouds retrieved using ground-based instruments. The goals of this intercomparison are to evaluate the accuracy of state-of-the-art algorithms, quantify the uncertainties, and make recommendations for their improvement.\r\n\r\nCurrently, there are significant discrepancies among the algorithms for ice clouds with very small optical depths (\u03c4 < 0.3) and those with 1 < \u03c4 < 5. The good news is that for thin clouds (0.3 < \u03c4 < 1), the algorithms tend to converge. In this first stage of the intercomparison, we present results from a representative case study, compare the retrieved cloud properties with aircraft and satellite measurements, and perform a radiative closure experiment to begin gauging the accuracy of these retrieval algorithms.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"2","pagerange":"191-204","doi":"10.1175\/BAMS-88-2-191","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5847","last_name":"Comstock","first_name":"","first_name_abbr":"J. M.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5848","last_name":"d'Entremont","first_name":"","first_name_abbr":"R.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5849","last_name":"DeSlover","first_name":"","first_name_abbr":"D.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5850","last_name":"Mace","first_name":"","first_name_abbr":"G. G.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5398","last_name":"Matrosov","first_name":"","first_name_abbr":"S. Y.","orcid":"","pos":"4","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5851","last_name":"McFarlane","first_name":"","first_name_abbr":"S. A.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5480","last_name":"Minnis","first_name":"","first_name_abbr":"P.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5852","last_name":"Mitchell","first_name":"","first_name_abbr":"D.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5489","last_name":"Sassen","first_name":"","first_name_abbr":"K.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5437","last_name":"Shupe","first_name":"","first_name_abbr":"M. D.","orcid":"","pos":"9","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5853","last_name":"Turner","first_name":"","first_name_abbr":"D. D.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5397","last_name":"Wang","first_name":"","first_name_abbr":"Z.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19244","title":"Evidence for a recurring eastern North America upper tropospheric ozone maximum during summer","abstract":"Daily ozonesondes were launched from 14 North American sites during August 2006, providing the best set of free tropospheric ozone measurements ever gathered across the continent in a single season. The data reveal a distinct upper tropospheric ozone maximum above eastern North America and centered over the southeastern USA. Recurring each year, the location and strength of the ozone maximum is influenced by the summertime upper tropospheric anticyclone that traps convectively lofted ozone, ozone precursors and lightning NOx above the southeastern USA. The North American summer monsoon that flows northward along the Rocky Mountains is embedded within the western side of the anticyclone and also marks the westernmost extent of the ozone maximum. Removing the influence from stratospheric intrusions, median ozone mixing ratios (78 ppbv) in the upper troposphere (>6 km) above Alabama, near the center of the anticyclone, were nearly twice the level above the U.S. west coast. Simulations by an atmospheric chemistry general circulation model indicate lightning NOx emissions led to the production of 25\u201330 ppbv of ozone at 250 hPa above the southern United States during the study period. On the regional scale the ozone enhancement above the southeastern United States produced a positive all-sky adjusted radiative forcing up to 0.50 W m\u22122.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D23304","doi":"10.1029\/2007JD008710","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5854","last_name":"Cooper","first_name":"","first_name_abbr":"O. R.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5525","last_name":"Trainer","first_name":"","first_name_abbr":"M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5552","last_name":"Wolfe","first_name":"","first_name_abbr":"D.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19245","title":"Ozone differences between near-coastal and offshore sites in New England: Role of meteorology","abstract":"Time series from two ozone monitoring stations are evaluated, one on an island several km off the New England coast, the other several km inland in New Hampshire. In the summer of 2002, during the New England Air Quality Study 2002 (NEAQS-2002), ozone measurements at the island station, Appledore Island (ADI), were consistently higher than at the inland station, Thompson Farm (TF). We hypothesized that the differences in ozone concentrations were due to transport differences driven by mesoscale meteorology, since neither site was in a source region. We found that the Appalachian Trough, coastal cold fronts and coastal stationary fronts at times caused TF to have westerly component flow while ADI had southerly component flow. In these situations, the southwesterly flow along the New England coast brought ozone and precursors to ADI from metropolitan areas to the southwest (e.g., Boston). Conversely, the air transported to TF from the west was contaminated by fewer upstream sources, and therefore the ozone was lower at TF. The sea breeze was also a factor, which tended to have the contrasting effect of nearly equalizing the ozone concentrations at the two sites by transporting ozone-rich air already impacting ADI inland to TF. Enhanced measurements from the NEAQS-2002 study were used in the analysis, including radar wind profilers, Doppler and ozone profiling lidars, and radiosondes launched from a ship. We also assessed model performance for two models, WRF\/Chem and MM5\/Chem, for four key days.","book_title":"","series":"","published_year":"2007","published_month":"8","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D16S91","doi":"10.1029\/2007JD008446","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5856","last_name":"Darby","first_name":"","first_name_abbr":"L. S.","orcid":"","pos":"0","branch_id":"18","staff_type_id":"1","short_name":"NIDIS","type":"Federal"},{"creator_id":"5334","last_name":"McKeen","first_name":"","first_name_abbr":"S. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5857","last_name":"Senff","first_name":"","first_name_abbr":"C. J.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5858","last_name":"Banta","first_name":"","first_name_abbr":"R. M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5859","last_name":"Post","first_name":"","first_name_abbr":"M. J.","orcid":"","pos":"5","branch_id":"9","staff_type_id":"5","short_name":"ASG","type":"other"},{"creator_id":"5553","last_name":"Brewer","first_name":"","first_name_abbr":"W. A.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5860","last_name":"Marchbanks","first_name":"","first_name_abbr":"R.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5861","last_name":"Alvarez II","first_name":"","first_name_abbr":"R. J.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5862","last_name":"Peckham","first_name":"","first_name_abbr":"S. E.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5863","last_name":"Mao","first_name":"","first_name_abbr":"H.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5864","last_name":"Talbot","first_name":"","first_name_abbr":"R.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19246","title":"The transient atmospheric circulation response to North Atlantic SST and sea ice anomalies","abstract":"The objective of this study is to investigate the transient evolution of the wintertime atmospheric circulation response to imposed patterns of SST and sea ice extent anomalies in the North Atlantic sector using a large ensemble of experiments with the NCAR Community Climate Model version 3 (CCM3). The initial adjustment of the atmospheric circulation is characterized by an out-of-phase relationship between geopotential height anomalies in the lower and upper troposphere localized to the vicinity of the forcing. This initial baroclinic response reaches a maximum amplitude in 5\u201310 days, and persists for 2\u20133 weeks. Diagnostic results with a linear primitive equation model indicate that this initial response is forced by diabatic heating anomalies in the lower troposphere associated with surface heat flux anomalies generated by the imposed thermal forcing. Following the initial baroclinic stage of adjustment, the response becomes progressively more barotropic and increases in both spatial extent and magnitude. The equilibrium stage of adjustment is reached in 2\u20132.5 months, and is characterized by an equivalent barotropic structure that resembles the hemispheric North Atlantic Oscillation\u2013Northern Annular Mode (NAO\u2013NAM) pattern, the model\u2019s leading internal mode of circulation variability over the Northern Hemisphere. The maximum amplitude of the equilibrium response is approximately 2\u20133 times larger than that of the initial response. The equilibrium response is primarily maintained by nonlinear transient eddy fluxes of vorticity (and, to a lesser extent, heat), with diabatic heating making a limited contribution in the vicinity of the forcing.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"18","pagerange":"4751-4767","doi":"10.1175\/JCLI4278.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5359","last_name":"Deser","first_name":"","first_name_abbr":"C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5865","last_name":"Tomas","first_name":"","first_name_abbr":"R. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5454","last_name":"Peng","first_name":"","first_name_abbr":"S.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19247","title":"Disappearing \"Alpine Tundra\" K\u00f6ppen climatic type in the western United States","abstract":"We examine changes in the areal extent of the K\u00f6ppen \u201calpine tundra\u201d climate classification type for the mountainous western United States following the work of Kottek et al. (2006). We find a significant decline in the area occupied by this climate category. In the early decades of the 20th century, the mean temperature of the warmest month in the areas of the western U.S. with nominal alpine tundra climates ranged largely between \u223c8.5\u00b0C and 9.5\u00b0C. In the last 20 years (1987\u20132006), rising temperatures have caused a significant fraction of these areas to exceed the 10\u00b0C threshold for alpine tundra classification. The result has been a 73% reduction in coverage of this climatic type. The remaining classified alpine tundra in the last 20 years now averages between \u223c9\u00b0C\u201310\u00b0C during the warmest month, so that continued warming past the classification threshold, would imply that areas where this climate type is found today in the West will no longer be present.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L18707","doi":"10.1029\/2007GL031253","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5515","last_name":"Diaz","first_name":"","first_name_abbr":"H. F.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5408","last_name":"Eischeid","first_name":"","first_name_abbr":"J. K.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19248","title":"Climate and Cultural History in the Americas: An Overview","abstract":"There is abundant historical evidence that climatic extremes in the past have led to significant and sometimes severe societal impacts. The severity of these impacts depends on the intensity and duration of the climatic event, social organization, and the prevailing socioeconomic conditions at the time of the climatic extreme. In this issue of Climatic Change we present the results from 12 studies, which document climatic extremes on different time scales and provide interesting evidence for direct and indirect social impacts of climatic changes in the Americas during the pre-Hispanic, colonial, and modern eras.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"Clim. Change","publisher":"","pages":"0","place_of_pub":"","volume":"83","number":"1-2","pagerange":"1-8","doi":"10.1007\/s10584-007-9237-4","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5515","last_name":"Diaz","first_name":"","first_name_abbr":"H. F.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5866","last_name":"Stahle","first_name":"","first_name_abbr":"D. W.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19249","title":"The global ocean data assimilation experiment high-resolution sea surface temperature pilot project","abstract":"A new generation of integrated sea surface temperature (SST) data products are being provided by the Global Ocean Data Assimilation Experiment (GODAE) High-Resolution SST Pilot Project (GHRSST-PP). These combine in near\u2013real time various SST data products from several different satellite sensors and in situ observations and maintain the fine spatial and temporal resolution needed by SST inputs to operational models. The practical realization of such an approach is complicated by the characteristic differences that exist between measurements of SST obtained from subsurface in-water sensors, and satellite microwave and satellite infrared radiometer systems. Furthermore, diurnal variability of SST within a 24-h period, manifested as both warm-layer and cool-skin deviations, introduces additional uncertainty for direct intercomparison between data sources and the implementation of data-merging strategies. The GHRSST-PP has developed and now operates an internationally distributed system that provides operational feeds of regional and global coverage high-resolution SST data products (better than 10 km and 6 h). A suite of online satellite SST diagnostic systems are also available within the project. All GHRSST-PP products have a standard format, include uncertainty estimates for each measurement, and are served to the international user community free of charge through a variety of data transport mechanisms and access points. They are being used for a number of operational applications. The approach will also be extended back to 1981 by a dedicated reanalysis project. This paper provides a summary overview of the GHRSST-PP structure, activities, and data products. For a complete discussion, and access to data products and services see the information online at www.ghrsst-pp.org.","book_title":"","series":"","published_year":"2007","published_month":"8","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"8","pagerange":"1197-1213","doi":"10.1175\/BAMS-88-8-1197","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5867","last_name":"Donlon","first_name":"","first_name_abbr":"C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5868","last_name":"Robinson","first_name":"","first_name_abbr":"I.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5869","last_name":"Casey","first_name":"","first_name_abbr":"K. S.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5870","last_name":"Vazquez-Cuervo","first_name":"","first_name_abbr":"J. ","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5871","last_name":"Armstrong","first_name":"","first_name_abbr":"E.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5872","last_name":"Arino","first_name":"","first_name_abbr":"O.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5873","last_name":"Gentemann","first_name":"","first_name_abbr":"C.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5874","last_name":"May","first_name":"","first_name_abbr":"D.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5875","last_name":"LeBorgne","first_name":"","first_name_abbr":"P.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5876","last_name":"Pioll\u00e9","first_name":"","first_name_abbr":"J.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5877","last_name":"Barton","first_name":"","first_name_abbr":"I.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5878","last_name":"Beggs","first_name":"","first_name_abbr":"H.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5879","last_name":"Poulter","first_name":"","first_name_abbr":"D. J. S.","orcid":"","pos":"12","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5880","last_name":"Merchant","first_name":"","first_name_abbr":"C. J.","orcid":"","pos":"13","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5881","last_name":"Bingham","first_name":"","first_name_abbr":"A.","orcid":"","pos":"14","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5882","last_name":"Heinz","first_name":"","first_name_abbr":"S.","orcid":"","pos":"15","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5883","last_name":"Harris","first_name":"","first_name_abbr":"A.","orcid":"","pos":"16","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5441","last_name":"Wick","first_name":"","first_name_abbr":"G. A.","orcid":"","pos":"17","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5885","last_name":"Emery","first_name":"","first_name_abbr":"B.","orcid":"","pos":"18","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5886","last_name":"Minnett","first_name":"","first_name_abbr":"P.","orcid":"","pos":"19","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5887","last_name":"Evans","first_name":"","first_name_abbr":"R.","orcid":"","pos":"20","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5888","last_name":"Llewellyn-Jones","first_name":"","first_name_abbr":"D. ","orcid":"","pos":"21","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5889","last_name":"Mutlow","first_name":"","first_name_abbr":"C.","orcid":"","pos":"22","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5517","last_name":"Reynolds","first_name":"","first_name_abbr":"R. W.","orcid":"","pos":"23","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5890","last_name":"Kawamura","first_name":"","first_name_abbr":"H.","orcid":"","pos":"24","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5891","last_name":"Rayner","first_name":"","first_name_abbr":"N.","orcid":"","pos":"25","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19250","title":"Transport of forest fire emissions from Alaska and the Yukon Territory to Nova Scotia during summer 2004","abstract":"Emissions from forest fires in Alaska and the Yukon Territory were observed at Chebogue Point, Nova Scotia (43.7\u00b0N, 66.1\u00b0W), between 11 and 13 July 2004. Smoke aerosols were first detected in the free troposphere by a Raman lidar and extended up to 8 km altitude. The plume was not evident at the surface until the second day, when increases in CO, acetonitrile (CH3CN), benzene, and aerosol mass concentrations were observed by in situ instrumentation. Enhancement ratios for each species relative to CO agreed with the range of values from other measurements of the same plume. The surface aerosols had an elevated black carbon fraction relative to both CO and organic matter, and the ratio of black to organic carbon was higher than what is typically observed in fresh smoke. The emissions were tracked back to Alaska and the Yukon Territory using aerosol optical depth measurements from the Aqua MODIS satellite instrument, and the transport was reconstructed using the GEOS-Chem and FLEXPART atmospheric models. The analysis suggests that aerosols were injected into the atmosphere in proportion to CO and that aerosol removal processes were weak during the 7 to 9 day transit time in the free troposphere. Transport of the tracers to the ground was strongly connected to synoptic-scale features in the surface meteorology.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D10S44","doi":"10.1029\/2006JD007716","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5892","last_name":"Duck","first_name":"","first_name_abbr":"T. J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5893","last_name":"Firanski","first_name":"","first_name_abbr":"B. J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19251","title":"Angular momentum in the global atmospheric circulation","abstract":"Angular momentum is a variable of central importance to the dynamics of the atmosphere both regionally and globally. Moreover, the angular momentum equations yield a precise description of the dynamic interaction of the atmosphere with the oceans and the solid Earth via various torques as exerted by friction, pressure against the mountains and the nonspherical shape of the Earth, and by gravity. This review presents recent work with respect to observations and the theory of atmospheric angular momentum of large-scale motions. It is mainly the recent availability of consistent global data sets spanning decades that sparked renewed interest in angular momentum. In particular, relatively reliable estimates of the torques are now available. In addition, a fairly wide range of theoretical aspects of the role of angular momentum in atmospheric large-scale dynamics is covered.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"Rev. Geophys.","publisher":"","pages":"0","place_of_pub":"","volume":"45","number":"","pagerange":"RG4007","doi":"10.1029\/2006RG000213","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5894","last_name":"Egger","first_name":"","first_name_abbr":" J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5676","last_name":"Weickmann","first_name":"","first_name_abbr":"K. M.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5895","last_name":"Hoinka","first_name":"","first_name_abbr":"K.-P.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19252","title":"Latitude\u2013Height Structure of the Atmospheric Angular Momentum Cycle Associated with the Madden\u2013Julian Oscillation","abstract":"The angular momentum cycle of the Madden\u2013Julian oscillation is analyzed by regressing the zonally averaged axial angular momentum (AAM) budget including fluxes and torques against the first two principal components P1 and P2 of the empirical orthogonal functions (EOFs) of outgoing longwave radiation (OLR). The maximum of P1 coincides with an OLR minimum near 150\u00b0E and a shift from anomalously negative AAM to positive AAM in the equatorial troposphere. AAM anomalies of one sign develop first in the upper-equatorial troposphere and then move downward and poleward to the surface of the subtropics within two weeks. During the same time the opposite sign AAM anomaly develops in the upper-equatorial troposphere. The tropical troposphere is warming when P1 approaches its maximum while the stratosphere is cooling. The torques are largest in the subtropics and are linked with the downward and poleward movement of AAM anomalies. The evolution is conveniently summarized using a time\u2013height depiction of the global mean AAM and vertical flux anomaly.","book_title":"","series":"","published_year":"2007","published_month":"4","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"4","pagerange":"1564-1575","doi":"10.1175\/MWR3363.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5896","last_name":"Egger","first_name":"","first_name_abbr":"J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5897","last_name":"Weickmann","first_name":"","first_name_abbr":"K.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19253","title":"Foreword to the Special Issue on the 2006 International Geoscience and Remote Sensing Symposium (IGARSS): \u201cRemote Sensing\u2014A Natural\u2013Global Partnership\u201d","abstract":"The 26 papers in this special issue were selected from the conference papers of the 2006 International Geoscience and Remote Sensing Symposium (IGARSS), which was held in Denver, Co, from July 31 to August 4.","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"IEEE Trans. Geosci. Remote Sens.","publisher":"","pages":"0","place_of_pub":"","volume":"45","number":"10","pagerange":"3003-3004","doi":"10.1109\/TGRS.2007.905970 ","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5898","last_name":"Emery","first_name":"","first_name_abbr":"W. J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5441","last_name":"Wick","first_name":"","first_name_abbr":"G. A.","orcid":"","pos":"1","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"}],"editors":[]},{"id":"19254","title":"Water-side turbulence enhancement of ozone deposition to the ocean","abstract":"A parameterization for the deposition velocity of an ocean-reactive atmospheric gas (such as ozone) is developed. The parameterization is based on integration of the turbulent-molecular transport equation (with a chemical source term) in the ocean. It extends previous work that only considered reactions within the oceanic molecular sublayer. The sensitivity of the ocean-side transport to reaction rate and wind forcing is examined. A more complicated case with a much more reactive thin surfactant layer is also considered. The full atmosphere-ocean deposition velocity is obtained by matching boundary conditions at the interface. For an assumed ocean reaction rate of 103 s\u22121, the enhancement for ozone deposition by oceanic turbulence is found to be up to a factor of three for meteorological data obtained in a recent cruise off the East Coast of the U.S.","book_title":"","series":"","published_year":"2007","published_month":"1","publication":"Atmos. Chem. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"7","number":"2","pagerange":"443-451","doi":"10.5194\/acp-7-443-2007","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5845","last_name":"Helmig","first_name":"","first_name_abbr":"D.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5899","last_name":"Ganzeveld","first_name":"","first_name_abbr":"L.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5900","last_name":"Hare","first_name":"","first_name_abbr":"J.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"}],"editors":[]},{"id":"19255","title":"High-frequency diffraction corrections to backscattering cross sections from a rough three-dimensional surface","abstract":"Diffraction corrections to scalar wave fields at perfectly free and rigid rough surfaces were derived by two iterations of the corresponding integral equations. These diffraction corrections to the pressure or normal velocity (which, in the geometrical optics limit, are doubled at perfectly rigid and free surfaces, respectively) were obtained with an accuracy of \u223c 1\/k2, where k is the wave number of incidence radiation. Based on these corrections to the surface fields, the backscattering cross sections at normal incidence from the statistically rough Gaussian surfaces were derived. It was found that for the gentle roughness, diffraction results in effective \u201csmoothing\u201d of roughness for rigid and free surfaces and increasing of the backscattering cross sections, but for a rigid surface with steep roughness, the \u201cfictitious\u201d surface can be more rough than the real one, and the diffraction corrections become negative.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"122","number":"3","pagerange":"1463-1471","doi":"10.1121\/1.2756794","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5901","last_name":"Fuks","first_name":"","first_name_abbr":"I.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"}],"editors":[]},{"id":"19256","title":"Statistics of travel time and intensity of two first arrivals of short pulses backscattered by a rough 3D surface","abstract":"The time history of a pulse backscattered by a rough surface contains information about the position of the surface and the properties of the scatterers. This information is utilized successfully in a number of remote sensing techniques ranging from echo sounding of the ocean bottom to medical ultrasonics and satellite altimetry. In the current paper, statistical properties of backscattered waves are considered in a geometrical optics approximation. The probing pulse duration is assumed to be sufficiently short so that signals backscattered in the vicinity of individual specular points on a rough surface do not overlap in time. Theoretical results previously obtained for a 2D problem [I. M. Fuks and O. A. Godin, 2005, Waves in Random and Complex Media, 14, 539\u2013562; M. I. Charnotskii and I. M. Fuks, 2005, Waves in Random and Complex Media, 15, 451\u2013467] are extended to wave scattering by 3D rough surfaces by following a mathematical approach developed in stochastic geometry. Predictions of an asymptotic theory are verified against results of Monte-Carlo simulations. Probability density functions of travel times and intensities of the first and second arrivals of the backscattered wave are quantified in terms of statistical moments of roughness assuming normal distribution of elevations. It is found that, as in the 2D case, the travel time and the intensity are strongly correlated; on average, the earlier a signal arrives, the smaller is its intensity.","book_title":"","series":"","published_year":"2007","published_month":"1","publication":"Waves Random Complex Media","publisher":"","pages":"0","place_of_pub":"","volume":"17","number":"1","pagerange":"9-27","doi":"10.1080\/17455030600798855","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5901","last_name":"Fuks","first_name":"","first_name_abbr":"I.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"},{"creator_id":"5569","last_name":"Charnotskii","first_name":"","first_name_abbr":"M. I.","orcid":"","pos":"1","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"},{"creator_id":"5606","last_name":"Godin","first_name":"","first_name_abbr":"O. A.","orcid":"","pos":"2","branch_id":"9","staff_type_id":"2","short_name":"ASG","type":"CIRES"}],"editors":[]},{"id":"19257","title":"Backscattering from a statistically rough 2-D surface: Diffraction corrections to geometrical optics cross sections","abstract":"Diffraction corrections (up to terms \u223c1\/k2) to the geometric optics backscattering cross sections from a statistically rough 2-D perfectly conducting surface were derived for TE- and TM-polarized electromagnetic waves based on the high-frequency asymptotic expansions of electric and magnetic fields at the surface obtained by Fuks (2004). It was shown that at steep incident angles, where the specular reflections play the main part in scattering, diffraction results can be interpreted as scattering by a fictitious surface, the roughness of which is gentler that the real surface at HH polarization and steeper at VV polarization. The HH\/VV polarization ratio (dB), being positive at steep incident angles, gradually decreases as the incident angle increases, and it becomes negative for moderate incident angles.","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"Radio Sci.","publisher":"","pages":"0","place_of_pub":"","volume":"42","number":"","pagerange":"RS6S25","doi":"10.1029\/2007RS003637","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5570","last_name":"Fuks","first_name":"","first_name_abbr":"I. M.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"}],"editors":[]},{"id":"19258","title":"Emergence of the acoustic Green's function from thermal noise","abstract":"The fluctuation-dissipation theorem is used to show how acoustic Green\u2019s functions corresponding to sound propagation in opposite directions between any two given points can be extracted from time series of thermal noise recorded at these points. The result applies to arbitrarily inhomogeneous, moving or motionless fluids with time-independent parameters, and demonstrates that the two-point correlation function of thermal noise contains as much information about the environment as can be obtained acoustically by placing transceivers at the two points.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"121","number":"2","pagerange":"EL96-EL102","doi":"10.1121\/1.2430764","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5606","last_name":"Godin","first_name":"","first_name_abbr":"O. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"2","short_name":"ASG","type":"CIRES"}],"editors":[]},{"id":"19259","title":"Restless rays, steady wave fronts","abstract":"Observations of underwater acoustic fields with vertical line arrays and numerical simulations of long-range sound propagation in an ocean perturbed by internal gravity waves indicate that acoustic wave fronts are much more stable than the rays comprising these wave fronts. This paper provides a theoretical explanation of the phenomenon of wave front stability in a medium with weak sound-speed perturbations. It is shown analytically that at propagation ranges that are large compared to the correlation length of the sound-speed perturbations but smaller than ranges at which ray chaos develops, end points of rays launched from a point source and having a given travel time are scattered primarily along the wave front corresponding to the same travel time in the unperturbed environment. The ratio of root mean square displacements of the ray end points along and across the unperturbed wave front increases with range as the ratio of ray length to correlation length of environmental perturbations. An intuitive physical explanation of the theoretical results is proposed. The relative stability of wave fronts compared to rays is shown to follow from Fermat\u2019s principle and dimensional considerations.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":" J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"122","number":"6","pagerange":"3353-3363","doi":"10.1121\/1.2799479","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5606","last_name":"Godin","first_name":"","first_name_abbr":"O. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"2","short_name":"ASG","type":"CIRES"}],"editors":[]},{"id":"19260","title":"Surface-to-volume wave conversion in shallow water with a gently sloping bottom","abstract":"Marine sediments support seismoacoustic surface waves, which can propagate along the seafloor, in deep and shallow water, and even onshore. Because of the strong attenuation of compressional and especially shear waves in the sediments, the surface waves can significantly contribute to the acoustic field far from the shore only through their coupling with volume waves in the water. We theoretically study the excitation of acoustic normal modes by seismoacoustic surface waves in a shallow-water waveguide with a sloping bottom consisting of unconsolidated marine sediments. It is found that the coupling primarily occurs in the vicinity of a modal cutoff. The effects of geoacoustic parameters and stratification of soft marine sediments on the efficiency of surface-to-volume conversion are investigated.","book_title":"","series":"","published_year":"2007","published_month":"11","publication":"Acoust. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"53","number":"6","pagerange":"714-720","doi":"10.1134\/S1063771007060097","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5606","last_name":"Godin","first_name":"","first_name_abbr":"O. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"2","short_name":"ASG","type":"CIRES"}],"editors":[]},{"id":"19261","title":"Transmission of low-frequency sound through the water-to-air interface","abstract":"L.M. Brekhovskikh revealed and studied the important role played by inhomogeneous waves emitted by a point source when they pass through an interface with a medium in which the velocity of sound is lower, for example, from water to air. This paper studies the energy characteristics of sound emitted into air by an underwater point source. The energy transfer due to inhomogeneous waves is shown to cause the phenomenon of anomalous transparency of the interface for low-frequency sound. The anomalous transparency manifests itself in that the energy flux through the interface increases with decreasing frequency of sound and, at sufficiently low frequencies, almost all of the acoustic energy produced by the underwater source is emitted into air. Conversely, at high frequencies, when the contribution of the inhomogeneous waves becomes negligible, the water-to-air interface is similar to a perfectly reflecting surface and almost all of the acoustic energy produced by the source is emitted into water. The anomalous transparency phenomenon changes the conventional opinion on the possibility of acoustic coupling between points in water and air and on the role played by physical processes evolving in the water column in generating atmospheric acoustic noise.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"Acoust. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"53","number":"3","pagerange":"305-312","doi":"10.1134\/S1063771007030074","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5606","last_name":"Godin","first_name":"","first_name_abbr":"O. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"2","short_name":"ASG","type":"CIRES"}],"editors":[]},{"id":"19262","title":"The nature of the rainfall onset over central South America","abstract":"The objective of this work is to provide a detailed description of the onset of the South American Monsoon based on precipitation observations available over tropical and subtropical South America. The analysis was also performed using outgoing longwave radiation (OLR) data in order to assess the ability of this particular dataset to reproduce the main features associated with precipitation evolution during austral spring. Results show that both OLR and precipitation data agree in describing the progression of convection from the northwest and southeast into central Brazil by the beginning of October. Moreover the assessment of available methods to identify onset dates shows that the method of Kousky (1988), based on the OLR evolution, provides the onset date in most of South America, without regionally adaptation, as the methods based on rainfall generally require. Composite fields show that rainfall in central Brazil begins with moderate rates, which are still lower than those observed over the northwestern and southeastern tropical regions. After the rainfall jump, that on average occurs three pentads later than the onset of rainfall, precipitation rates increase over central Brazil and similar rates are observed over the entire tropical region. It is suggested that transient activity, which occurs around the onset period when the atmospheric mean conditions are getting more unstable as they approach summer\u2013like conditions, is the one that imprints a rainfall\u2013jump feature in the precipitation evolution. The character of changes in the precipitation rate, as the rainy season develops, provides complementary information that can be used together with onset date.","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"Atmosfera","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"4","pagerange":"377-394","doi":"","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5902","last_name":"Gonz\u00e1lez","first_name":"","first_name_abbr":"M.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5903","last_name":"Vera","first_name":"","first_name_abbr":"C. S.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5414","last_name":"Liebmann","first_name":"","first_name_abbr":"B.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5904","last_name":"Marengo","first_name":"","first_name_abbr":"J. A.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5905","last_name":"Kousky","first_name":"","first_name_abbr":"V.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5415","last_name":"Allured","first_name":"","first_name_abbr":"D.","orcid":"","pos":"5","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19263","title":"On the turbulent Prandtl number in the stable atmospheric boundary layer","abstract":"This study focuses on the behaviour of the turbulent Prandtl number, Pr t , in the stable atmospheric boundary layer (SBL) based on measurements made during the Surface Heat Budget of the Arctic Ocean experiment (SHEBA). It is found that Pr t increases with increasing stability if Pr t is plotted vs. gradient Richardson number, Ri; but at the same time, Pr t decreases with increasing stability if Pr t is plotted vs. flux Richardson number, Rf, or vs. \u03b6 =  z\/L. This paradoxical behaviour of the turbulent Prandtl number in the SBL derives from the fact that plots of Pr t vs. Ri (as well as vs. Rf and \u03b6) for individual 1-h observations and conventional bin-averaged values of the individual quantities have built-in correlation (or self-correlation) because of the shared variables. For independent estimates of how Pr t behaves in very stable stratification, Pr t is plotted against the bulk Richardson number; such plots have no built-in correlation. These plots based on the SHEBA data show that, on the average, Pr t decreases with increasing stability and Pr t <  1 in the very stable case. For specific heights and stabilities, though, the turbulent Prandtl number has more complicated behaviour in the SBL.","book_title":"","series":"","published_year":"2007","published_month":"11","publication":"Boundary-Layer Meteorol.","publisher":"","pages":"0","place_of_pub":"","volume":"125","number":"2","pagerange":"329-341","doi":"10.1007\/s10546-007-9192-7","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5381","last_name":"Grachev","first_name":"","first_name_abbr":"A. A.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5384","last_name":"Andreas","first_name":"","first_name_abbr":"E. L.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"2","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5385","last_name":"Guest","first_name":"","first_name_abbr":"P. S.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5383","last_name":"Persson","first_name":"","first_name_abbr":"P. O. G.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"}],"editors":[]},{"id":"19264","title":"SHEBA flux-profile relationships in the stable atmospheric boundary layer","abstract":"Measurements of atmospheric turbulence made during the Surface Heat Budget of the Arctic Ocean Experiment (SHEBA) are used to examine the profile stability functions of momentum, \u03c6 m , and sensible heat, \u03c6 h , in the stably stratified boundary layer over the Arctic pack ice. Turbulent fluxes and mean meteorological data that cover different surface conditions and a wide range of stability conditions were continuously measured and reported hourly at five levels on a 20-m main tower for 11 months. The comprehensive dataset collected during SHEBA allows studying \u03c6 m and \u03c6 h in detail and includes ample data for the very stable case. New parameterizations for \u03c6 m (\u03b6) and \u03c6 h (\u03b6) in stable conditions are proposed to describe the SHEBA data; these cover the entire range of the stability parameter \u03b6 = z\/L from neutral to very stable conditions, where L is the Obukhov length and z is the measurement height. In the limit of very strong stability, \u03c6 m follows a \u03b6 1\/3 dependence, whereas \u03c6 h initially increases with increasing \u03b6, reaches a maximum at \u03b6 \u2248 10, and then tends to level off with increasing \u03b6. The effects of self-correlation, which occur in plots of \u03c6 m and \u03c6 h versus \u03b6, are reduced by using an independent bin-averaging method instead of conventional averaging.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"Boundary-Layer Meteorol.","publisher":"","pages":"0","place_of_pub":"","volume":"124","number":"3","pagerange":"315-333","doi":"10.1007\/s10546-007-9177-6","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5381","last_name":"Grachev","first_name":"","first_name_abbr":"A. A.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5384","last_name":"Andreas","first_name":"","first_name_abbr":"E. L.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"2","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5385","last_name":"Guest","first_name":"","first_name_abbr":"P. S.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5383","last_name":"Persson","first_name":"","first_name_abbr":"P. O. G.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"}],"editors":[]},{"id":"19265","title":"Tropical Pacific - mid-latitude teleconnections in medieval times","abstract":"Terrestrial and marine late Holocene proxy records from the western and central US suggest that climate between approximately 500 and 1350 a.d. was marked by generally arid conditions with episodes of severe centennial-scale drought, elevated incidence of wild fire, cool sea surface temperatures (SSTs) along the California coast, and dune mobilization in the western plains. This Medieval Climate Anomaly (MCA) was followed by wetter conditions and warming coastal SSTs during the transition into the \u201cLittle Ice Age\u201d (LIA). Proxy records from the tropical Pacific Ocean show contemporaneous changes indicating cool central and eastern tropical Pacific SSTs during the MCA, with warmer than modern temperatures in the western equatorial Pacific. This pattern of mid-latitude and tropical climate conditions is consistent with the hypothesis that the dry MCA in the western US resulted (at least in part) from tropically forced changes in winter NH circulation patterns like those associated with modern La Ni\u00f1a episodes. We examine this hypothesis, and present other analyses showing that the imprint of MCA climate change appears in proxy records from widely distributed regions around the planet, and in many cases is consistent with a cool medieval tropical Pacific. One example, explored with numerical model results, is the suggestion of increased westerlies and warmer winter temperatures over northern Europe during medieval times. An analog technique for the combined use of proxy records and model results, Proxy Surrogate Reconstruction (PSR), is introduced.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"Clim. Change","publisher":"","pages":"0","place_of_pub":"","volume":"83","number":"1-2","pagerange":"241-285","doi":"10.1007\/s10584-007-9239-2","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5906","last_name":"Graham","first_name":"","first_name_abbr":"N. E.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5907","last_name":"Hughes","first_name":"","first_name_abbr":"M. K.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5908","last_name":"Ammann","first_name":"","first_name_abbr":"C. M.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5909","last_name":"Cobb","first_name":"","first_name_abbr":"K. M.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5339","last_name":"Hoerling","first_name":"","first_name_abbr":"M. P.","orcid":"","pos":"4","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5910","last_name":"Kennett","first_name":"","first_name_abbr":"D. J.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5911","last_name":"Kennett","first_name":"","first_name_abbr":"J. P.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5912","last_name":"Rei","first_name":"","first_name_abbr":"B.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5913","last_name":"Stott","first_name":"","first_name_abbr":"L.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5914","last_name":"Wigand","first_name":"","first_name_abbr":"P. E.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"9695","last_name":"Xu","first_name":"Taiyi","first_name_abbr":"T.","orcid":"","pos":"10","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19266","title":"Comments on \"Calibrated Surface Temperature Forecasts from the Canadian Ensemble Prediction System Using Bayesian Model Averaging.\"","abstract":"N\/A","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"12","pagerange":"4226-4230","doi":"10.1175\/2007MWR1963.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19267","title":"Toward Making the AMS Carbon Neutral: Offsetting the Impacts of Flying to Conferences","abstract":"N\/A","book_title":"","series":"","published_year":"2007","published_month":"11","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"11","pagerange":"1816-1819","doi":"10.1175\/BAMS-88-11-1816","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19268","title":"Ensemble Calibration of 500-hPa Geopotential Height and 850-hPa and 2-m Temperatures Using Reforecasts","abstract":"An examination of the benefits of ensemble forecast calibration was performed for three variables: 500-hPa geopotential height (Z500), 850-hPa temperature (T850), and 2-m temperature (T2M). A large reforecast dataset was used for the calibration. Two calibration methods were examined: a correction for a gross bias in the forecast and an analog method that implicitly adjusted for bias, spread, and applied a downscaling where appropriate. The characteristics of probabilistic forecasts from the raw ensemble were also considered. Forecasts were evaluated using rank histograms and the continuous ranked probability skill score. T2M rank histograms showed a high population of extreme ranks at all leads, and a correction for model bias alleviated this only slightly. The extreme ranks of Z500 rank histograms were slightly underpopulated at short leads, though slightly overpopulated at longer leads. T850 had characteristics in between those of T2M and Z500. Accordingly, Z500 was the most skillful variable without calibration and the variable least improved by calibration, and the bias correction achieved most of the improvement in skill. For T850, there was a more substantial additional increase in skill relative to the bias correction when the analog technique was applied. For T2M forecasts, probabilistic forecasts from the raw ensemble were the least skillful, the application of a bias correction substantially increased the skill, and the application of the analog technique produced the largest further increase in skill relative to the bias correction. Hence, reforecast datasets may be particularly helpful in the improvement of probabilistic forecasts of the variables that are most directly relevant to many forecast users (i.e., the sensible surface-weather variables).","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"9","pagerange":"3273-3280","doi":"10.1175\/MWR3468.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5395","last_name":"Whitaker","first_name":"","first_name_abbr":"J. S.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19269","title":"On stochastic parameter estimation using data assimilation","abstract":"Data assimilation-based parameter estimation can be used to deterministically tune forecast models. This work demonstrates that it can also be used to provide parameter distributions for use by stochastic parameterization schemes. While parameter estimation is (theoretically) straightforward to perform, it is not clear how one should physically interpret the parameter values obtained. Structural model inadequacy implies that one should not search for a deterministic \u201cbest\u201d set of parameter values, but rather allow the parameter values to change as a function of state; different parameter values will be needed to compensate for the state-dependent variations of realistic model inadequacy. Over time, a distribution of parameter values will be generated and this distribution can be sampled during forecasts. The current work addresses the ability of ensemble-based parameter estimation techniques utilizing a deterministic model to estimate the moments of stochastic parameters. It is shown that when the system of interest is stochastic the expected variability of a stochastic parameter is biased when a deterministic model is employed for parameter estimation. However, this bias is ameliorated through application of the Central Limit Theorem, and good estimates of both the first and second moments of the stochastic parameter can be obtained. It is also shown that the biased variability information can be utilized to construct a hybrid stochastic\/deterministic integration scheme that is able to accurately approximate the evolution of the true stochastic system.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Physica D","publisher":"","pages":"0","place_of_pub":"","volume":"230","number":"1-2","pagerange":"88-98","doi":"10.1016\/j.physd.2006.11.006","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5915","last_name":"Hansen","first_name":"","first_name_abbr":" J. A. ","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5503","last_name":"Penland","first_name":"","first_name_abbr":"C.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"}],"editors":[]},{"id":"19270","title":"Explaining the record US warmth of 2006","abstract":"This study explores origins for record setting 2006 temperatures over the conterminous United States. The efficacy of two mechanisms is quantified; one associated with sea surface temperatures (SSTs) in the equatorial Pacific related to El Ni\u00f1o, and the other associated with increased greenhouse gas concentrations. We use historical records of US temperatures observed during past El Ni\u00f1os, model simulations subjected to El Ni\u00f1o SST conditions and to projections of the 2006 greenhouse gas concentrations. We use ensemble methods to yield probabilistic estimates of temperature anomalies related to each forcing. Neither historical data nor model simulations reveal a US warm response to El Ni\u00f1o indicating it was not a factor in elevating US temperatures. Instead, over half of the anomalous warmth in 2006 is attributed to greenhouse gas forcing, whose strength now exceeds the standard deviation of natural fluctuations. We conclude that the record warmth was primarily due to human influences.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L17704","doi":"10.1029\/2007GL030643","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5339","last_name":"Hoerling","first_name":"","first_name_abbr":"M. P.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5408","last_name":"Eischeid","first_name":"","first_name_abbr":"J. K.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5730","last_name":"Quan","first_name":"","first_name_abbr":"X.-W.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"9695","last_name":"Xu","first_name":"Taiyi","first_name_abbr":"T.","orcid":"","pos":"3","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19271","title":"Detection and Correction of Diurnal Sampling Bias in HIRS\/2 Brightness Temperatures","abstract":"Diurnal sampling biases arise in the High-Resolution Infrared Radiation Sounder (HIRS) satellite observations because some of the NOAA polar-orbiting satellites drift significantly from their original local observation time. Such bias adversely affects interpretation of these data for climate studies. Twenty-six years of HIRS\/2 radiance satellite data (1979\u20132004) were examined by creating monthly mean gridded data that categorize the observations by local observing time through averaging ascending and descending orbits separately. Corresponding HIRS\/2 simulated radiance data from the Geophysical Fluid Dynamics Laboratory (GFDL) climate model were constructed using HIRS\/2 satellite sampling and were found to accurately represent the diurnal sampling bias. Correction of the HIRS\/2 observations from the observed diurnal sampling bias was using the model simulations of HIRS brightness temperatures to adjust the observed brightness temperatures to the model daily mean. The diurnal bias was found to vary with channel, surface type, latitude, satellite, and cloud cover, but showed little dependence on satellite scan angle. Diurnal bias is most pronounced for ascending orbit observations of the afternoon [1400 local solar time (LST)] satellites with 60\u00b0N to 60\u00b0S domain averaged brightness temperatures variations up to 0.78 K yr\u22121. Lower tropospheric temperature and water vapor channels contained the largest bias, and biases over land were more than twice as large as those over the ocean. Brightness temperature adjustments of up to 10 K were needed in the most extreme situations.","book_title":"","series":"","published_year":"2007","published_month":"8","publication":"J. Atmos. Oceanic Technol.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"8","pagerange":"1425-1438","doi":"10.1175\/JTECH2062.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5402","last_name":"Jackson","first_name":"","first_name_abbr":"D. L.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5401","last_name":"Soden","first_name":"","first_name_abbr":"B. J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19272","title":"Wind Stress Drag Coefficient over the Global Ocean","abstract":"Interannual and climatological variations of wind stress drag coefficient (CD) are examined over the global ocean from 1998 to 2004. Here CD is calculated using high temporal resolution (3- and 6-hourly) surface atmospheric variables from two datasets: 1) the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) and 2) the Navy Operational Global Atmospheric Prediction System (NOGAPS). The stability-dependent CD algorithm applied to both datasets gives almost identical values over most of the global ocean, confirming the validity of results. Overall, major findings of this paper are as follows: 1) the CD value can change significantly (e.g., >50%) on 12-hourly time scales around the Kuroshio and Gulf Stream current systems; 2) there is strong seasonal variability in CD, but there is not much interannual change in the spatial variability for a given month; 3) a global mean CD \u2248 1.25 \u00d7 10\u22123 is found in all months, while CD \u2265 1.5 \u00d7 10\u22123 is prevalent over the North Pacific and North Atlantic Oceans and in southern high-latitude regions as well, and CD \u2264 1.0 \u00d7 10\u22123 is typical in the eastern equatorial Pacific cold tongue; and 4) including the effects of air\u2013sea stability on CD generally causes an increase of >20% in comparison to the one calculated based on neutral conditions in the tropical regions. Finally, spatially and temporally varying CD fields are therefore needed for a variety of climate and air\u2013sea interaction studies.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"23","pagerange":"5856-5864","doi":"10.1175\/2007JCLI1825.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5916","last_name":"Kara","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5917","last_name":"Wallcraft","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5918","last_name":"Metzger","first_name":"","first_name_abbr":"E. J.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5919","last_name":"Hurlburt","first_name":"","first_name_abbr":"H. E.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"}],"editors":[]},{"id":"19273","title":"Advances in the Use of Historical Marine Climate Data","abstract":"N\/A\r\n","book_title":"","series":"","published_year":"2007","published_month":"4","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"4","pagerange":"559-564","doi":"10.1175\/BAMS-88-4-559","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5920","last_name":"Kent","first_name":"","first_name_abbr":"E.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5514","last_name":"Woodruff","first_name":"","first_name_abbr":"S. D.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5891","last_name":"Rayner","first_name":"","first_name_abbr":"N.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5921","last_name":"Arbetter","first_name":"","first_name_abbr":"T.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5922","last_name":"Folland","first_name":"","first_name_abbr":"C.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5923","last_name":"Koek","first_name":"","first_name_abbr":"F.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5924","last_name":"Parker","first_name":"","first_name_abbr":"D.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5925","last_name":"Reynolds","first_name":"","first_name_abbr":"R.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5926","last_name":"Saunders","first_name":"","first_name_abbr":"R.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5927","last_name":"Smolyanitsky","first_name":"","first_name_abbr":"V.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5928","last_name":"Worley","first_name":"","first_name_abbr":"S.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5929","last_name":"Yoshida","first_name":"","first_name_abbr":"T.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19274","title":"Metadata from WMO Publication No. 47 and an Assessment of Voluntary Observing Ship Observation Heights in ICOADS","abstract":"It is increasingly recognized that metadata can significantly improve the quality of scientific analyses and that the availability of metadata is particularly important for the study of climate variability. The International Comprehensive Ocean\u2013Atmosphere Data Set (ICOADS) contains in situ observations frequently used in climate studies, and this paper describes the ship metadata that are available to complement ICOADS. This paper highlights the metadata available in World Meteorological Organization Publication No. 47 that include information on measurement methods and observation heights. Changing measurement methods and heights are known to be a cause of spurious change in the climate record. Here the authors focus on identifying measurement heights for air temperature and wind speed and also give information on SST measurement depths.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Atmos. Oceanic Technol.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"2","pagerange":"214-234","doi":"10.1175\/JTECH1949.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5930","last_name":"Kent","first_name":"","first_name_abbr":"E. C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5514","last_name":"Woodruff","first_name":"","first_name_abbr":"S. D.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5931","last_name":"Berry","first_name":"","first_name_abbr":"D. I.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19275","title":"Application of CALINE4 to roadside NO\/NO2 transformations","abstract":"\r\nThe CALINE4 roadway dispersion model has been applied to concentrations of NOx and NO2 measured near Gandy Boulevard in Tampa, FL (USA) during May 2002. A NOx emission factor of 0.86 gr mi\u22121 was estimated by treating NO+NO2 (NOx) as a conserved species and minimizing the differences between measured and calculated NOx concentrations. This emission factor was then used to calculate NO2 concentrations using the NO\/NO2 transformation reactions built into CALINE4. A comparison of measured and calculated NO2 concentrations indicates that for ambient O3 concentrations less than 40 ppb the model under-predicts the chemical transformation of NO. The enhanced transformation of NO may be due to reactions of NO with oxidants such as peroxy radicals that are present either in the atmosphere or in vehicle exhaust.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Atmos. Environ.","publisher":"","pages":"0","place_of_pub":"","volume":"41","number":"20","pagerange":"4270-4280","doi":"10.1016\/j.atmosenv.2006.06.066","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5932","last_name":"Kenty","first_name":"","first_name_abbr":"K. L.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5933","last_name":"Poor","first_name":"","first_name_abbr":"N. D.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5934","last_name":"Kronmiller","first_name":"","first_name_abbr":"K. G.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5935","last_name":"McClenny","first_name":"","first_name_abbr":"W.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5936","last_name":"King","first_name":"","first_name_abbr":"C.","orcid":"","pos":"4","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5937","last_name":"Atkeson","first_name":"","first_name_abbr":"T.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5938","last_name":"Campbell","first_name":"","first_name_abbr":"S. W.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19276","title":"Decadal- to interannual-scale source water variations in the Caribbean Sea recorded by Puerto Rican coral radiocarbon","abstract":"Water that forms the Florida Current, and eventually the Gulf Stream, coalesces in the Caribbean from both subtropical and equatorial sources. The equatorial sources are made up of, in part, South Atlantic water moving northward and compensating for southward flow at depth related to meridional overturning circulation. Subtropical surface water contains relatively high amounts of radiocarbon (14C), whereas equatorial waters are influenced by the upwelling of low 14C water and have relatively low concentrations of 14C. We use a 250 year record of \u039414C in a coral from southwestern Puerto Rico along with previously published coral \u039414C records as tracers of subtropical and equatorial water mixing in the northern Caribbean. Data generated in this study and from other studies indicate that the influence of either of the two water masses can change considerably on interannual to interdecadal time scales. Variability due to ocean dynamics in this region is large relative to variability caused by atmospheric 14C changes, thus masking the Suess effect at this site. A mixing model produced using coral \u039414C illustrates the time varying proportion of equatorial versus subtropical waters in the northern Caribbean between 1963 and 1983. The results of the model are consistent with linkages between multidecadal thermal variability in the North Atlantic and meridional overturning circulation. Ekman transport changes related to tradewind variability are proposed as a possible mechanism to explain the observed switches between relatively low and high \u039414C values in the coral radiocarbon records.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"Clim. Dyn.","publisher":"","pages":"0","place_of_pub":"","volume":"29","number":"1","pagerange":"51-62","doi":"10.1007\/s00382-007-0224-2","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5939","last_name":"Kilbourne","first_name":"","first_name_abbr":"K. H.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5940","last_name":"Quinn","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5941","last_name":"Guilderson","first_name":"","first_name_abbr":"T. P.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5378","last_name":"Webb","first_name":"","first_name_abbr":"R. S. ","orcid":"","pos":"3","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5942","last_name":"Taylor","first_name":"","first_name_abbr":"F. W.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19277","title":"The Atmospheric Radiation Measurement Program Cloud Profiling Radars: Second-Generation Sampling Strategies, Processing, and Cloud Data Products","abstract":"The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program operates millimeter-wavelength cloud radars in several climatologically distinct regions. The digital signal processors for these radars were recently upgraded and allow for enhancements in the operational parameters running on them. Recent evaluations of millimeter-wavelength cloud radar signal processing performance relative to the range of cloud dynamical and microphysical conditions encountered at the ARM Program sites have indicated that improvements are necessary, including significant improvement in temporal resolution (i.e., less than 1 s for dwell and 2 s for dwell and processing), wider Nyquist velocities, operational dealiasing of the recorded spectra, removal of pulse compression while sampling the boundary layer, and continuous recording of Doppler spectra. A new set of millimeter-wavelength cloud radar operational modes that incorporate these enhancements is presented. A significant change in radar sampling is the introduction of an uneven mode sequence with 50% of the sampling time dedicated to the lower atmosphere, allowing for detailed characterization of boundary layer clouds. The changes in the operational modes have a substantial impact on the postprocessing algorithms that are used to extract cloud information from the radar data. New methods for postprocessing of recorded Doppler spectra are presented that result in more accurate identification of radar clutter (e.g., insects) and extraction of turbulence and microphysical information. Results of recent studies on the error characteristics of derived Doppler moments are included so that uncertainty estimates are now included with the moments. The microscale data product based on the increased temporal resolution of the millimeter-wavelength cloud radars is described. It contains the number of local maxima in each Doppler spectrum, the Doppler moments of the primary peak, uncertainty estimates for the Doppler moments of the primary peak, Doppler moment shape parameters (e.g., skewness and kurtosis), and clear-air clutter flags.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"J. Atmos. Oceanic Technol.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"7","pagerange":"1199-1214","doi":"10.1175\/JTECH2033.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5492","last_name":"Kollias","first_name":"","first_name_abbr":"P.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5943","last_name":"Clothiaux","first_name":"","first_name_abbr":"E. E.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5944","last_name":"Miller","first_name":"","first_name_abbr":"M. A.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5945","last_name":"Luke","first_name":"","first_name_abbr":" E. P.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5946","last_name":"Johnson","first_name":"","first_name_abbr":" K. L.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5947","last_name":"Moran","first_name":"","first_name_abbr":"K. P.","orcid":"","pos":"5","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5948","last_name":"Widener","first_name":"","first_name_abbr":"K. B.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5478","last_name":"Albrecht","first_name":"","first_name_abbr":"B. A.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19278","title":"Influence of the Atlantic multidecadal oscillation on the winter climate of East China","abstract":"\r\nThe Atlantic Multidecadal Oscillation (AMO), the multidecadal variation of North Atlantic sea surface temperature (SST), exhibits an oscillation with a period of 65\u201380 years and an amplitude of 0.4\u00b0C. Observational composite analyses reveal that the warm phase AMO is linked to warmer winters in East China, with enhanced precipitation in the north of this region and reduced precipitation in the south, on multidecadal time scales. The pattern is reversed during the cold phase AMO. Whether the AMO acts as a forcing of the multidecadal winter climate of East China is explored by investigating the atmospheric response to warm AMO SST anomalies in a large ensemble of atmospheric general circulation model (AGCM) experiments. The results from three AGCMs are consistent and suggest that the AMO warmth favors warmer winters in East China. This influence is realized through inducing negative surface air pressure anomalies in the hemispheric-wide domain extending from the midlatitude North Atlantic to midlatitude Eurasia. These negative surface anomalies favor the weakening of the Mongolian Cold High, and thus induce a weaker East Asian Winter Monsoon.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Adv. Atmos. Sci.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"1","pagerange":"126-135","doi":"10.1007\/s00376-007-0126-6","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5456","last_name":"Li","first_name":"","first_name_abbr":"S.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"5","short_name":"PSD1","type":"other"},{"creator_id":"5949","last_name":"Bates","first_name":"","first_name_abbr":"G. T.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19279","title":"Dynamics of the Extratropical Response to a Tropical Atlantic SST Anomaly","abstract":"Previous atmospheric general circulation model (AGCM) experiments revealed that atmospheric responses to a tropical Atlantic sea surface temperature anomaly (SSTA) were asymmetric with respect to the sign of the SSTA. A positive SSTA produced a south\u2013north dipole in geopotential heights, much like the North Atlantic Oscillation (NAO), while a negative SSTA yielded an eastward-propagating wave train, with the northern lobe of the NAO absent.\r\n\r\nHere these height responses are decomposed into components that are symmetric or antisymmetric with respect to the sign of the SSTA. The symmetric, or notionally linear, component is a nearly south\u2013north dipole projecting on the NAO, while the antisymmetric, or notionally nonlinear, component is a different dipole. Experiments with a diagnostic linear baroclinic model (LBM) suggest that both components are maintained primarily by transient-eddy forcing. Dynamical mechanisms for the formation of the two components are explored using the LBM and a nonlinear barotropic vorticity equation model (BVM). Transient-eddy feedback is sufficient to explain the linear response. The NAO-like linear response occurs when the initial heating induces transient-eddy forcing in the exit of the Atlantic jet. The structure of the background absolute vorticity in this region is such that this transient-eddy forcing induces a nearly north\u2013south dipole in anomalous geopotential heights. When the nonlinear self-interaction of this transient-induced low-frequency perturbation is included in the BVM, the dipole axis tilts to the east or west, resulting in a response that is nonlinear about the sign of the forcing.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"3","pagerange":"560-574","doi":"10.1175\/JCLI4014.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5456","last_name":"Li","first_name":"","first_name_abbr":"S.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"5","short_name":"PSD1","type":"other"},{"creator_id":"5455","last_name":"Robinson","first_name":"","first_name_abbr":"W. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5339","last_name":"Hoerling","first_name":"","first_name_abbr":"M. P.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5676","last_name":"Weickmann","first_name":"","first_name_abbr":"K. M.","orcid":"","pos":"3","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19280","title":"Onset and end of the rainy season in South America in observations and the ECHAM 4.5 atmospheric general circulation model","abstract":"Rainfall in South America as simulated by a 24-ensemble member of the ECHAM 4.5 atmospheric general circulation model is compared and contrasted with observations (in areas in which data are available) for the period 1976\u20132001. Emphasis is placed on determining the onset and end of the rainy season, from which its length and rain rate are determined.\r\n\r\nIt is shown that over large parts of the domain the onset and ending dates are well simulated by the model, with biases of less than 10 days. There is a tendency for model onset to occur early and ending to occur late, resulting in a simulated rainy season that is on average too long in many areas. The model wet season rain rate also tends to be larger than observed.\r\n\r\nTo estimate the relative importance of errors in wet season length and rain rate in determining biases in the annual total, adjusted totals are computed by substituting both the observed climatological wet season length and rate for those of the model. Problems in the rain rate generally are more important than problems in the length.\r\n\r\nThe wet season length and rain rate also contribute substantially to interannual variations in the annual total. These quantities are almost independent, and it is argued that they are each associated with different mechanisms.\r\n\r\nThe observed onset dates almost always lie within the range of onset of the ensemble members, even in the areas with a large model onset bias. In some areas, though, the model does not perform well. In southern Brazil the model ensemble average onset always occurs in summer, whereas the observations show that winter is often the wettest period. Individual members, however, do occasionally show a winter rainfall peak. In southern Northeast Brazil the model has a more distinct rainy season than is observed. In the northwest Amazon the model annual cycle is shifted relative to that observed, resulting in a model bias.\r\n\r\nNo interannual relationship between model and observed onset dates is expected unless onset in the model and observations has a mutual relationship with SST anomalies. In part of the near-equatorial Amazon, there does exist an interannual relationship between onset dates. Previous studies have shown that in this area there is a relationship between SST anomalies and variations in seasonal total rainfall.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"10","pagerange":"2037-2050","doi":"10.1175\/JCLI4122.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5414","last_name":"Liebmann","first_name":"","first_name_abbr":"B.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5950","last_name":"Camargo","first_name":"","first_name_abbr":"S. J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5951","last_name":"Seth","first_name":"","first_name_abbr":"A.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"4","short_name":"NONE","type":"Contractor"},{"creator_id":"5952","last_name":"Marengo","first_name":"","first_name_abbr":" J. A.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5953","last_name":"Carvalho","first_name":"","first_name_abbr":"L. M. V.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"4","short_name":"NONE","type":"Contractor"},{"creator_id":"5415","last_name":"Allured","first_name":"","first_name_abbr":"D.","orcid":"","pos":"5","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5954","last_name":"Fu","first_name":"","first_name_abbr":"R.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5903","last_name":"Vera","first_name":"","first_name_abbr":"C. S.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19281","title":"Atmospheric bridge, oceanic tunnel, and global climatic teleconnections","abstract":"We review teleconnections within the atmosphere and ocean, their dynamics and their role in coupled climate variability. We concentrate on teleconnections in the latitudinal direction, notably tropical-extratropical and interhemispheric interactions, and discuss the timescales of several teleconnection processes. The tropical impact on extratropical climate is accomplished mainly through the atmosphere. In particular, tropical Pacific sea surface temperature anomalies impact extratropical climate variability through stationary atmospheric waves and their interactions with midlatitude storm tracks. Changes in the extratropics can also impact the tropical climate through upper ocean subtropical cells at decadal and longer timescales. On the global scale the tropics and subtropics interact through the atmospheric Hadley circulation and the oceanic subtropical cell. The thermohaline circulation can provide an effective oceanic teleconnection for interhemispheric climate interactions.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Rev. Geophys.","publisher":"","pages":"0","place_of_pub":"","volume":"45","number":"","pagerange":"RG2005","doi":"10.1029\/2005RG000172","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5419","last_name":"Liu","first_name":"","first_name_abbr":"Z.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"4","short_name":"NONE","type":"Contractor"},{"creator_id":"5358","last_name":"Alexander","first_name":"","first_name_abbr":"M. A.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19282","title":"Comparison of water vapor measurements by airborne Sun photometer and near-coincident in situ and satellite sensors during INTEX\/ITCT","abstract":"We have retrieved columnar water vapor (CWV) from measurements acquired by the 14-channel NASA Ames Airborne Tracking Sun photometer (AATS-14) during 19 Jetstream 31 (J31) flights over the Gulf of Maine in summer 2004 in support of the Intercontinental Chemical Transport Experiment (INTEX)\/Intercontinental Transport and Chemical Transformation (ITCT) experiments. In this paper we compare AATS-14 water vapor retrievals during aircraft vertical profiles with measurements by an onboard Vaisala HMP243 humidity sensor and by ship radiosondes and with water vapor profiles retrieved from AIRS measurements during eight Aqua overpasses. We also compare AATS CWV and MODIS infrared CWV retrievals during five Aqua and five Terra overpasses. For 35 J31 vertical profiles, mean (bias) and RMS AATS-minus-Vaisala layer-integrated water vapor (LWV) differences are \u22127.1% and 8.8%, respectively. For 22 aircraft profiles within 1 hour and 130 km of radiosonde soundings, AATS-minus-sonde bias and RMS LWV differences are \u22125.4% and 10.7%, respectively, and corresponding J31 Vaisala-minus-sonde differences are 2.3% and 8.4%, respectively. AIRS LWV retrievals within 80 km of J31 profiles yield lower bias and RMS differences compared to AATS or Vaisala retrievals than do AIRS retrievals within 150 km of the J31. In particular, for AIRS-minus-AATS LWV differences, the bias decreases from 8.8% to 5.8%, and the RMS difference decreases from 21.5% to 16.4%. Comparison of vertically resolved AIRS water vapor retrievals (LWVA) to AATS values in fixed pressure layers yields biases of \u22122% to +6% and RMS differences of \u223c20% below 700 hPa. Variability and magnitude of these differences increase significantly above 700 hPa. MODIS IR retrievals of CWV in 205 grid cells (5 \u00d7 5 km at nadir) are biased wet by 10.4% compared to AATS over-ocean near-surface retrievals. The MODIS-Aqua subset (79 grid cells) exhibits a wet bias of 5.1%, and the MODIS-Terra subset (126 grid cells) yields a wet bias of 13.2%.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D12S16","doi":"10.1029\/2006JD007733","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5955","last_name":"Livingston","first_name":"","first_name_abbr":"J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5956","last_name":"Schmid","first_name":"","first_name_abbr":"B.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5552","last_name":"Wolfe","first_name":"","first_name_abbr":"D.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19283","title":"The NOAA Twin Otter and its role in BRACE: A comparison of aircraft and surface trace gas measurements","abstract":"A DeHavilland DHC-6 Twin Otter, operated by the National Oceanic and Atmospheric Administration, was deployed in Tampa, FL to measure aerosols and primary and secondary trace gases in support of the Bay Regional Atmospheric Chemistry Experiment (BRACE). The Twin Otter repeatedly overflew the surface chemistry monitoring super site near Sydney, FL to assess the comparability of surface and airborne datasets and the spatial representativeness of the surface measurements. Prior to comparing the chemical datasets, we evaluated the comparability of the standards used to calibrate surface and airborne detectors, as well as the uniformity of wind fields aloft and at the surface. Under easterly flow, when the dearth of significant upwind emission sources promoted chemical homogeneity at Sydney, trace gas concentrations at the surface and aloft were generally well correlated; R2 ranged from 0.4396 for H2O2 to 0.9738 for O3, and was typically better than 0.70 for NO, NO2, NOY, HNO3, HCHO, and SO2. Mean ratios of aircraft-to-surface concentrations during 10 overflights of Sydney were as follows: 1.002\u00b10.265 (NO), 0.948\u00b10.183 (NO2), 1.010\u00b10.214 (NOY), 0.941\u00b10.263 (HCHO), and 0.952\u00b10.046 (O3). Poorer agreement and larger variability in measured ratios were noted for SO2 (1.764\u00b10.559), HNO3 (1.291\u00b10.391), and H2O2 (1.200\u00b10.657). Under easterly flow, surface measurements at Sydney were representative of conditions over horizontal scales as large as 50 km and agreed well with airborne values throughout the depth of the turbulently mixed boundary layer at mid-day. Westerly flow advected the Tampa urban plume over the site; under these conditions, as well as during transitional periods associated with the development of the land\u2013sea breeze, surface conditions were representative of smaller spatial scales. Finally, we estimate possible errors in future measurement-model comparisons likely to arise from fine scale (or subgrid;<2 km) variability of trace gas concentrations. Large subgrid variations in concentration fields were observed downwind of large emission point sources, and persisted across multiple model grid cells (distances>4 km) in coherent plumes. Variability at the edges of the well-mixed urban plume, and at the interface of the land\u2013sea breeze circulation, was significantly smaller. This suggests that even a failure of modeled wind fields to resolve the sea breeze return can induce moderate, but not overwhelming, errors in simulated concentration fields and dependent chemical processes.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Atmos. Environ.","publisher":"","pages":"0","place_of_pub":"","volume":"41","number":"20","pagerange":"4190-4209","doi":"10.1016\/j.atmosenv.2006.07.060","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5957","last_name":"Luke","first_name":"","first_name_abbr":"W. T.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5958","last_name":"Arnold","first_name":"","first_name_abbr":" J. R.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5936","last_name":"King","first_name":"","first_name_abbr":"C.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"}],"editors":[]},{"id":"19284","title":"Collocated Radar and Radiosonde Observations of a Double-Brightband Melting Layer in Northern California","abstract":"A strong elevated temperature inversion in a landfalling winter storm in northern California produced two simultaneous melting layers with associated radar bright bands. The storm was observed with scanning and profiling radars. Serial radiosonde launches from the scanning radar site precisely documented the evolving temperature structure of the air mass that produced the double bright band. The radiosonde and radar observations, which were coincident in location and time, clearly illustrate the cause (two melting layers) and effect (two bright bands) of this unusual phenomenon. An automated algorithm for determining the melting-layer height from profiling radar data was tested on this situation. In its operational form, the algorithm detects only the lower melting layer, but in modified form it is capable of detecting both melting layers simultaneously.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"5","pagerange":"2016-2024","doi":"10.1175\/MWR3383.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5426","last_name":"Martner","first_name":"","first_name_abbr":"B. E.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5440","last_name":"Neiman","first_name":"","first_name_abbr":"P. J.","orcid":"","pos":"1","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"2","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"}],"editors":[]},{"id":"19285","title":"Modeling backscatter properties of snowfall at millimeter wavelengths","abstract":"Ground-based vertically pointing and airborne\/spaceborne nadir-pointing millimeter-wavelength radars are being increasingly used worldwide. Though such radars are primarily designed for cloud remote sensing, they can also be used for precipitation measurements including snowfall estimates. In this study, modeling of snowfall radar properties is performed for the common frequencies of millimeter-wavelength radars such as those used by the U.S. Department of Energy\u2019s Atmospheric Radiation Measurement Program (Ka and W bands) and the CloudSat mission (W band). Realistic snowflake models including aggregates and single dendrite crystals were used. The model input included appropriate mass\u2013size and terminal fall velocity\u2013size relations and snowflake orientation and shape assumptions. It was shown that unlike in the Rayleigh scattering regime, which is often applicable for longer radar wavelengths, the spherical model does not generally satisfactorily describe scattering of larger snowflakes at millimeter wavelengths. This is especially true when, due to aerodynamic forcing, these snowflakes are oriented primarily with their major dimensions in the horizontal plane and the zenith\/nadir radar pointing geometry is used. As a result of modeling using the experimental snowflake size distributions, radar reflectivity\u2013liquid equivalent snowfall rates (Ze\u2013S) relations are suggested for \u201cdry\u201d snowfalls that consist of mostly unrimed snowflakes containing negligible amounts of liquid water. Owing to uncertainties in the model assumptions, these relations, which are derived for the common Ka- and W-band radar frequencies, have significant variability in their coefficients that can exceed a factor of 2 or so. Modeling snowfall attenuation suggests that the attenuation effects in \u201cdry\u201d snowfall can be neglected at the Ka band for most practical cases, while at the W band attenuation may need to be accounted for in heavier snowfalls observed at longer ranges.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Atmos. Sci.","publisher":"","pages":"0","place_of_pub":"","volume":"64","number":"5","pagerange":"1727-1736","doi":"10.1175\/JAS3904.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5398","last_name":"Matrosov","first_name":"","first_name_abbr":"S. Y.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"}],"editors":[]},{"id":"19286","title":"Potential for attenuation-based estimations of rainfall rate from CloudSat","abstract":"Attenuation of radar signals in rain increases with frequency while the variability of non-attenuated reflectivity of rainfall diminishes as resonance scattering effects become more pronounced at higher radar frequencies. At mm-wavelength frequencies, attenuation often becomes the dominant factor responsible for apparent reflectivity changes in vertical. This study presents an attenuation-based method to retrieve vertical profiles of rain rate from nadir-pointing W-band (94 GHz) radars. The quantitative assessments of retrieval errors are discussed, and an illustration of the retrievals using measurements from the spaceborne 94 GHz CloudSat radar is shown. As a consistency check, the spaceborne W-band radar retrievals are compared with concurrent estimates from a ground-based weather surveillance radar.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L05817","doi":"10.1029\/2006GL029161","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5398","last_name":"Matrosov","first_name":"","first_name_abbr":"S. Y.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"}],"editors":[]},{"id":"19287","title":"A Polarimetric Radar Approach to Identify Rain, Melting-Layer, and Snow Regions for Applying Corrections to Vertical Profiles of Reflectivity","abstract":"This article describes polarimetric X-band radar-based quantitative precipitation estimations (QPE) under conditions of low freezing levels when, even at the lowest possible elevation angles, radar resolution volumes at longer ranges are in melting-layer or snow regions while it rains at the ground. A specifically adjusted vertical-profile-of-reflectivity (VPR) approach is introduced. The mean VPR is constructed based on the range\u2013height indicator scans, and the effects of smoothing of brightband (BB) features with range are accounted for. A principal feature of the suggested QPE approach is the determination of the reflectivity BB boundaries and freezing-level heights on a beam-by-beam basis using the copolar correlation coefficient \u03c1hv, which is routinely available from the X-band radar measurements. It is shown that this coefficient provides a robust discrimination among the regions of rain, melting hydrometeors, and snow. The freezing-level estimates made using \u03c1hv were within 100\u2013200 m from the corresponding estimates of the 0\u00b0 isotherm heights from radiosonde soundings. The suggested VPR approach with the polarimetric determination of the reflectivity BB boundaries was used for QPE during the wintertime deployment of the NOAA X-band radar as part of the 2006 Hydrometeorological Test Bed (HMT-06) field experiment in the California Sierra Nevada foothills. It is shown that this approach noticeably improves radar-rainfall accumulation estimates. The use of the HMT-06 mean X-band reflectivity\u2013rain-rate (Zeh\u2013R) relation resulted in an approximately 65% relative standard deviation of radar estimates from the surface rain gauges if no VPR adjustments were made. Applying the VPR approach with polarimetric detection of the melting layer resulted in reduction of the corresponding relative standard deviation by about a factor of 2.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Appl. Meteor. Climatol.","publisher":"","pages":"0","place_of_pub":"","volume":"46","number":"2","pagerange":"154-166","doi":"10.1175\/JAM2508.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5398","last_name":"Matrosov","first_name":"","first_name_abbr":"S. Y.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5959","last_name":"Clark","first_name":"","first_name_abbr":"K. A.","orcid":"","pos":"1","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5365","last_name":"Kingsmill","first_name":"","first_name_abbr":"D. E.","orcid":"","pos":"2","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"}],"editors":[]},{"id":"19288","title":"Modification of the atmospheric boundary layer by a small island: observations from Nauru","abstract":"Nauru, a small island in the tropical Pacific, generates cloud plumes that may grow to over 100-km lengths. This study uses observations to examine the mesoscale disturbance of the marine atmospheric boundary layer by the island that produces these cloud plumes. Observations of the surface layer were made from two ships in the vicinity of Nauru and from instruments on the island. The structure of the atmospheric boundary layer over the island was investigated using aircraft flights. Cloud production over Nauru was examined using remote sensing instruments. The diurnal cycles of surface meteorology and radiation are characterized at a point near the west (downwind) coast of Nauru. The spatial variation of surface meteorology and radiation are also examined using surface and aircraft measurements. During the day, the island surface layer is warmer than the marine surface layer and wind speed is lower than over the ocean. Surface heating forces the growth of a thermal internal boundary layer, within which a plume of cumulus clouds forms. Cloud production begins early in the morning over the ocean near the island\u2019s lee shore; as heating intensifies during the day, cloud production moves upwind over Nauru. These clouds form a plume that may extend over 100 km downwind of Nauru. Aircraft observations showed that a plume of warm, dry air develops over the island that extends 15\u201320 km downwind before dissipating. Limited observations suggest that the cloud plume may be sustained farther downwind of Nauru by a pair of convective rolls. Suggestions for further investigation of the cloud plume are made.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"3","pagerange":"891-905","doi":"10.1175\/MWR3319.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5960","last_name":"Matthews","first_name":"","first_name_abbr":" S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5961","last_name":"Hacker","first_name":"","first_name_abbr":" J. M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5962","last_name":"Cole","first_name":"","first_name_abbr":"J.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5900","last_name":"Hare","first_name":"","first_name_abbr":"J.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"5","short_name":"PSD3","type":"other"},{"creator_id":"5963","last_name":"Long","first_name":"","first_name_abbr":"C. N.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5964","last_name":"Reynolds","first_name":"","first_name_abbr":"R. M.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19289","title":"Analysis of Radiosonde and Ground-Based Remotely Sensed PWV Data from the 2004 North Slope of Alaska Arctic Winter Radiometric Experiment","abstract":"During 9 March\u20139 April 2004, the North Slope of Alaska Arctic Winter Radiometric Experiment was conducted at the Atmospheric Radiation Measurement Program\u2019s (ARM) \u201cGreat White\u201d field site near Barrow, Alaska. The major goals of the experiment were to compare microwave and millimeter wavelength radiometers and to develop forward models in radiative transfer, all with a focus on cold (temperature from 0\u00b0 to \u221240\u00b0C) and dry [precipitable water vapor (PWV) < 0.5 cm] conditions. To supplement the remote sensors, several radiosonde packages were deployed: Vaisala RS90 launched at the ARM Duplex and at the Great White and Sippican VIZ-B2 operated by the NWS. In addition, eight dual-radiosonde launches were conducted at the Duplex with Vaisala RS90 and Sippican GPS Mark II, the latter one modified to include a chilled mirror humidity sensor. Temperature comparisons showed a nighttime bias between VIZ-B2 and RS90, which reached 3.5\u00b0C at 30 hPa. Relative humidity comparisons indicated better than 5% average agreement between the RS90 and the chilled mirror. A bias of about 20% for the upper troposphere was found in the VIZ-B2 and the Mark II measurements relative to both RS90 and the chilled mirror.\r\n\r\nComparisons in PWV were made between a microwave radiometer, a microwave profiler, a global positioning system receiver, and the radiosonde types. An RMS agreement of 0.033 cm was found between the radiometer and the profiler and better than 0.058 cm between the radiometers and GPS. RS90 showed a daytime dry bias on PWV of about 0.02 cm.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"J. Atmos. Oceanic Technol.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"3","pagerange":"415-431","doi":"10.1175\/JTECH1982.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5429","last_name":"Mattioli","first_name":"","first_name_abbr":"V.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5430","last_name":"Westwater","first_name":"","first_name_abbr":"E. R.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5345","last_name":"Cimini","first_name":"","first_name_abbr":"D.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5965","last_name":"Liljegren","first_name":"","first_name_abbr":"J. C.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5966","last_name":"Lesht","first_name":"","first_name_abbr":"B. M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5431","last_name":"Gutman","first_name":"","first_name_abbr":"S. I.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5967","last_name":"Schmidlin","first_name":"","first_name_abbr":"F. J.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19290","title":"Evaluation of several PM2.5 forecast models using data collected during the ICARTT\/NEAQS 2004 field study","abstract":"Real-time forecasts of PM2.5 aerosol mass from seven air quality forecast models (AQFMs) are statistically evaluated against observations collected in the northeastern United States and southeastern Canada from two surface networks and aircraft data during the summer of 2004 International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)\/New England Air Quality Study (NEAQS) field campaign. The AIRNOW surface network is used to evaluate PM2.5 aerosol mass, the U.S. EPA STN network is used for PM2.5 aerosol composition comparisons, and aerosol size distribution and composition measured from the NOAA P-3 aircraft are also compared. Statistics based on midday 8-hour averages, as well as 24-hour averages are evaluated against the AIRNOW surface network. When the 8-hour average PM2.5 statistics are compared against equivalent ozone statistics for each model, the analysis shows that PM2.5 forecasts possess nearly equivalent correlation, less bias, and better skill relative to the corresponding ozone forecasts. An analysis of the diurnal variability shows that most models do not reproduce the observed diurnal cycle at urban and suburban monitor locations, particularly during the nighttime to early morning transition. While observations show median rural PM2.5 levels similar to urban and suburban values, the models display noticeably smaller rural\/urban PM2.5 ratios. The ensemble PM2.5 forecast, created by combining six separate forecasts with equal weighting, is also evaluated and shown to yield the best possible forecast in terms of the statistical measures considered. The comparisons of PM2.5 composition with NOAA P-3 aircraft data reveals two important features: (1) The organic component of PM2.5 is significantly underpredicted by all the AQFMs and (2) those models that include aqueous phase oxidation of SO2 to sulfate in clouds overpredict sulfate levels while those AQFMs that do not include this transformation mechanism underpredict sulfate. Errors in PM2.5 ammonium levels tend to correlate directly with errors in sulfate. Comparisons of PM2.5 composition with the U.S. EPA STN network for three of the AQFMs show that sulfate biases are consistently lower at the surface than aloft. Recommendations for further research and analysis to help improve PM2.5 forecasts are also provided.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D10S20","doi":"10.1029\/2006JD007608","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5968","last_name":"McKeen","first_name":"","first_name_abbr":"S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5969","last_name":"Chung","first_name":"","first_name_abbr":"S. H.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5433","last_name":"Wilczak","first_name":"","first_name_abbr":"J. M.","orcid":"","pos":"2","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5434","last_name":"Grell","first_name":"","first_name_abbr":"G.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5428","last_name":"Djalalova","first_name":"","first_name_abbr":"I.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19291","title":"Analysis of the Dominant Mode of Convectively Coupled Kelvin Waves in the West African Monsoon","abstract":"The dominant mode of convectively coupled Kelvin waves has been detected over the Atlantic and Africa during northern summer by performing composite analyses on observational fields based on an EOF reconstructed convection index over West Africa. Propagating eastward, many waves originate from the Pacific sector, interact with deep convection of the marine ITCZ over the Atlantic and the continental ITCZ over West and central Africa, and then weaken over East Africa and the Indian Ocean. It has been shown that they are able to modulate the life cycle and track of individual westward-propagating convective systems. Their mean kinematic characteristics comprise a wavelength of 8000 km, and a phase speed of 15 m s\u22121, leading to a period centered on 6 to 7 days. The African Kelvin wave activity displays large seasonal variability, being highest outside of northern summer when the ITCZ is close to the equator, facilitating the interactions between convection and these equatorially trapped waves. The convective and dynamical patterns identified over the Atlantic and Africa show some resemblance to the theoretical equatorially trapped Kelvin wave solution on an equatorial \u03b2 plane. Most of the flow is in the zonal direction as predicted by theory, and there is a tendency for the dynamical fields to be symmetric about the equator, even though the ITCZ is concentrated well north of the equator at the full development of the African monsoon. In the upper troposphere and the stratosphere, the temperature contours slope sharply eastward with height, as expected from an eastward-moving heat source that forces a dry Kelvin wave response. It is finally shown that the mean impact of African Kelvin waves on rainfall and convection is of the same level as African easterly waves.","book_title":"","series":"","published_year":"2007","published_month":"4","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"8","pagerange":"1487-1503","doi":"10.1175\/JCLI4059.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5970","last_name":"Mounier","first_name":"","first_name_abbr":"F.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5611","last_name":"Kiladis","first_name":"","first_name_abbr":"G. N.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5971","last_name":"Janicot","first_name":"","first_name_abbr":"S.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19292","title":"Sound propagation in an unstable atmospheric layer","abstract":"The equation of sound propagation in an unstable medium produced by the presence of supersaturated water vapor in it, which can appear in a hurricane area, is derived. This equation takes into account the effects of sound velocity dispersion, amplification, damping, and nonlinear effects. Some solutions to this equation are presented, illustrating the specific features of sound propagation in an unstable medium.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"Acoust. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"53","number":"3","pagerange":"417-420","doi":"10.1134\/S1063771007030153","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5571","last_name":"Naugolnykh","first_name":"","first_name_abbr":"K. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"},{"creator_id":"5972","last_name":"Rybak","first_name":"","first_name_abbr":"S. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19293","title":"Interannual to Decadal Predictability of Tropical and North Pacific Sea Surface Temperatures","abstract":"A multivariate empirical model is used to show that predictability of the dominant patterns of tropical and North Pacific oceanic variability, El Ni\u00f1o\u2013Southern Oscillation (ENSO), and the Pacific decadal oscillation (PDO), is mostly limited to little more than a year, despite the presence of spectral peaks on decadal time scales. The model used is a linear inverse model (LIM) derived from the observed simultaneous and 1-yr lag correlation statistics of July\u2013June-averaged SST from the Hadley Centre Global Sea Ice and Sea Surface Temperature (HadISST) dataset for the years 1900\u20132002. The model accurately reproduces the power spectra of the data, including interannual and interdecadal spectral peaks that are significant relative to univariate red noise. Eigenanalysis of the linear dynamical operator yields propagating eigenmodes that correspond to these peaks but have very short decay times and, thus, limited predictability.\r\n\r\nLonger-term predictability does exist, however, due to two stationary eigenmodes that are more weakly damped. These eigenmodes do not strongly correspond to the canonical ENSO and PDO patterns. Instead, one is similar to the 1900\u20132002 trend and might represent anthropogenic effects, while the second represents multidecadal fluctuations of a pattern that potentially represents natural decadal variability; however, neither attribution can be made unambiguously with the analysis presented in this paper. Predictability of these two stationary eigenmodes is significantly enhanced by tropical\u2013North Pacific coupling. Neither stationary eigenmode is well captured in the control run of any coupled GCM in the CMIP-3 project of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), perhaps because in all of the GCMs tropical SST decadal variability is too weak and North Pacific SSTs are too independent of the Tropics.\r\n\r\nA key implication of this analysis is that the PDO may represent not a single physical mode but rather the sum of several phenomena, each of which represents a different red noise with its own autocorrelation time scale and spatial pattern. The sum of these red noises can give rise to apparent PDO \u201cregime shifts\u201d and seeming characteristics of a long memory process. Such shifts are not predictable beyond the time scale of the most rapidly decorrelating noise, less than two years, although the expected duration of regimes may be determined from the relative amplitudes of different eigenmodes.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"11","pagerange":"2333-2356","doi":"10.1175\/JCLI4165.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5502","last_name":"Newman","first_name":"","first_name_abbr":"M.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19294","title":"Mesoscale model performance with assimilation of wind profiler data: Sensitivity to assimilation parameters and network configuration","abstract":"The performance of the nudging scheme in the MM5 numerical model is evaluated for a 4-day simulation of an ozone episode during the TexAQS-2000 field study. Quality-controlled horizontal wind data from five boundary layer profilers spaced 30\u201350 km apart are used as input data for the nudging as well as for quantification of model errors. Observations from selected profilers are withheld to provide independent data to evaluate the performance of the model. A series of experiments are conducted to estimate the overall model performance as well as the dependence of the model performance on nudging parameters and on profiler network configuration. Within the profiler network, nudging generally reduces 4-day average biases in the wind components to less than 0.3 m s\u22121 and yields rms errors averaging 1.75 m s\u22121 to 2.08 m s\u22121, with the best model performance at about 500\u20131500 m above ground level. Rms errors without data assimilation are about twice as large. Model errors, with and without assimilation, are generally largest at night. Wind fields that are more accurate in a statistical sense can be obtained by simpler analysis schemes, but the consistent dynamical evolution of all meteorological variables, such as the pattern of temperatures associated with corrected sea breeze location and intensity, are lost. Tests with a reduced profiler network showed that a single profiler in an appropriate upstream location can produce model performance equivalent to that from a four-profiler network surrounding the validation station.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D09119","doi":"10.1029\/2006JD007633","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5973","last_name":"Nielsen-Gammon","first_name":"","first_name_abbr":"J. W.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5974","last_name":"McNider","first_name":"","first_name_abbr":"R. T.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5551","last_name":"Angevine","first_name":"","first_name_abbr":"W. M.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5975","last_name":"Knupp","first_name":"","first_name_abbr":"K.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19295","title":"Pad\u00e9 approximation in time-domain boundary conditions of porous surfaces","abstract":"Formulation and implementation of time-domain boundary conditions (TDBCs) at the surface of a reactive porous material are made challenging by the slow decay, complexity, or noncausal nature of many commonly used models of porous materials. In this paper, approaches are described that improve computational efficiency and enforce causality. One approach involves approximating the known TDBC for the modified Zwikker-Kosten impedance model as a summation of decaying exponential functions. A second approach, which can be applied to any impedance model, involves replacing the characteristic admittance with its Pad\u00e9 approximation. Then, approximating fractional derivatives with decaying exponentials, a causal and recursive TDBC is formulated","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"122","number":"1","pagerange":"107-112","doi":"10.1121\/1.2743153","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5443","last_name":"Ostashev","first_name":"","first_name_abbr":"V. E.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5804","last_name":"Collier","first_name":"","first_name_abbr":"S. L.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19296","title":"Radiation force and shear motions in inhomogeneous media","abstract":"An action of radiation force induced by ultrasonic beam in waterlike media such as biological tissues (where the shear modulus is small as compared to the bulk compressibility) is considered. A new, nondissipative mechanism of generation of shear displacement due to a smooth (nonreflecting) medium inhomogeneity is suggested, and the corresponding medium displacement is evaluated. It is shown that a linear primary acoustic field in nondissipative, isotropic elastic medium cannot excite a nonpotential radiation force and, hence, a shear motion, whereas even smooth inhomogeneity makes this effect possible. An example is considered showing that the generated displacement pulse can be significantly longer than the primary ultrasound pulse. It is noted that, unlike the dissipative effect, the nondissipative action on a localized inhomogeneity (such as a lesion in a tissue) changes its sign along the beam axis, thus stretching or compressing the focus area.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"121","number":"3","pagerange":"1324-1331","doi":"10.1121\/1.2532113","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5821","last_name":"Ostrovsky","first_name":"","first_name_abbr":"L. A.","orcid":"","pos":"0","branch_id":"9","staff_type_id":"4","short_name":"ASG","type":"Contractor"},{"creator_id":"5976","last_name":"Sutin","first_name":"","first_name_abbr":"A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19297","title":"Rain in shallow cumulus over the ocean - The RICO campaign","abstract":"Shallow, maritime cumuli are ubiquitous over much of the tropical oceans, and characterizing their properties is important to understanding weather and climate. The Rain in Cumulus over the Ocean (RICO) field campaign, which took place during November 2004\u2013January 2005 in the trades over the western Atlantic, emphasized measurements of processes related to the formation of rain in shallow cumuli, and how rain subsequently modifies the structure and ensemble statistics of trade wind clouds. Eight weeks of nearly continuous S-band polarimetric radar sampling, 57 flights from three heavily instrumented research aircraft, and a suite of ground- and ship-based instrumentation provided data on trade wind clouds with unprecedented resolution. Observational strategies employed during RICO capitalized on the advances in remote sensing and other instrumentation to provide insight into processes that span a range of scales and that lie at the heart of questions relating to the cause and effects of rain from shallow maritime cumuli.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"12","pagerange":"1912-1928","doi":"10.1175\/BAMS-88-12-1912","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5486","last_name":"Rauber","first_name":"","first_name_abbr":"R. M.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5977","last_name":"Stevens","first_name":"","first_name_abbr":"B.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19298","title":"Applications of Monsoon Research: Opportunities to Inform Decision Making and Reduce Regional Vulnerability","abstract":"This article presents ongoing efforts to understand interactions between the North American monsoon and society in order to develop applications for monsoon research in a highly complex, multicultural, and binational region. The North American monsoon is an annual precipitation regime that begins in early June in Mexico and progresses northward to the southwestern United States. The region includes stakeholders in large urban complexes, productive agricultural areas, and sparsely populated arid and semiarid ecosystems. The political, cultural, and socioeconomic divisions between the United States and Mexico create a broad range of sensitivities to climate variability as well as capacities to use forecasts and other information to cope with climate.\r\n\r\nThis paper highlights methodologies to link climate science with society and to analyze opportunities for monsoon science to benefit society in four sectors: natural hazards management, agriculture, public health, and water management. A list of stakeholder needs and a calendar of decisions is synthesized to help scientists link user needs to potential forecasts and products. To ensure usability of forecasts and other research products, iterative scientist\u2013stakeholder interactions, through integrated assessments, are recommended. These knowledge-exchange interactions can improve the capacity for stakeholders to use forecasts thoughtfully and inform the development of research, and for the research community to obtain feedback on climate-related products and receive insights to guide research direction. It is expected that integrated assessments can capitalize on the opportunities for monsoon science to inform decision making and, in the best instances, reduce regional climate vulnerabilities and enhance regional sustainability.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"9","pagerange":"1608-1627","doi":"10.1175\/JCLI4098.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5978","last_name":"Ray","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5979","last_name":"Garfin","first_name":"","first_name_abbr":"G. M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5980","last_name":"Wilder","first_name":"","first_name_abbr":"M.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5981","last_name":"V\u00e1squez-Le\u00f3n","first_name":"","first_name_abbr":"M. ","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5982","last_name":"Lenart","first_name":"","first_name_abbr":"M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5983","last_name":"Comrie","first_name":"","first_name_abbr":"A. C.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19299","title":"Foreword to the special issue on the 9th specialist meeting on microwave radiometry and remote sensing applications (MicroRad ","abstract":"The 38 papers in this special issue were originally presented at the 9th Specialist Meeting on Microwave Radiometry and Remote Sensing Applications (MicroRad '06). These papers are organized into topical areas and applications, which are in the general order of the MicroRad technical sessions: Radiometer Calibration and RFI Mitigation (4); Synthetic Aperture Radiometry (3); Land and Vegetation (6); Ocean Salinity (5); Ocean Wind (4); Atmosphere (3); Temperature and Humidity Sounding (8); and Precipitation (5).","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"IEEE Trans. Geosci. Remote Sens.","publisher":"","pages":"0","place_of_pub":"","volume":"45","number":"7","pagerange":"1903-1906","doi":"10.1109\/TGRS.2007.900318","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5984","last_name":"Reising","first_name":"","first_name_abbr":"S. C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5470","last_name":"Marzano","first_name":"","first_name_abbr":"F. S.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5555","last_name":"Njoku","first_name":"","first_name_abbr":"E. G.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5430","last_name":"Westwater","first_name":"","first_name_abbr":"E. R.","orcid":"","pos":"3","branch_id":"12","staff_type_id":"5","short_name":"CET","type":"other"}],"editors":[]},{"id":"19300","title":"Analysis of a Reconstructed Oceanic Kelvin Wave Dynamic Height Dataset for the Period 1974\u20132005","abstract":"Intraseasonal oceanic Kelvin waves are the dominant mode of variability in the thermocline of the equatorial Pacific. Dynamic height data from the Tropical Atmosphere Ocean (TAO) Array of buoys moored in the tropical Pacific offer a convenient grid on which to study the waves but can only be effectively applied to study basinwide wave activity since about 1988 because of insufficient data at earlier times. Kelvin wave signals are also present in sea level data from island and coastal sites from the University of Hawaii Sea Level Center, some of which are available from before 1970 and up to 2003. This work describes a technique for reconstructing equatorial dynamic height data back to 1974, by utilizing regression relationships between the TAO data and daily sea level time series from 11 stations in the tropical Pacific. The reconstructed data are analyzed for skill in approximating Kelvin wave signals when TAO data are available. Reconstructed Kelvin wave signals prior to the TAO period are then analyzed for consistency with the wind stress anomalies that are responsible for generating the waves.\r\n\r\nA regression analysis showing intraseasonal patterns of convection and winds that occur during periods of adjustment toward El Ni\u00f1o conditions is applied during the period 1974\u201387 for comparison with an earlier result calculated from TAO data for 1988\u20132005. Systematic changes in Kelvin wave phase speed with respect to ENSO documented for the latter period are confirmed in the earlier reconstructed dataset.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"17","pagerange":"4341-4355","doi":"10.1175\/JCLI4249.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5604","last_name":"Roundy","first_name":"","first_name_abbr":"P. E.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5611","last_name":"Kiladis","first_name":"","first_name_abbr":"G. N.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19301","title":"Multiscale Impacts of Variable Heating in Climate","abstract":"\r\nWhile it is obvious that the mean diabatic forcing of the atmosphere is crucial for maintaining the mean climate, the importance of diabatic forcing fluctuations is less evident in this regard. Such fluctuations do not appear directly in the equations of the mean climate but affect the mean indirectly through their effects on the time-mean transient-eddy fluxes of heat, momentum, and moisture. How large are these effects? What are the effects of tropical phenomena associated with substantial heating variations such as ENSO and the MJO? To what extent do variations of the extratropical surface heat fluxes and precipitation affect the mean climate? What are the effects of the rapid \u201cstochastic\u201d components of the heating fluctuations? Most current climate models misrepresent ENSO and the MJO and ignore stochastic forcing; they therefore also misrepresent their mean effects. To what extent does this contribute to climate model biases and to projections of climate change?\r\n\r\nThis paper provides an assessment of such impacts by comparing with observations a long simulation of the northern winter climate by a dry adiabatic general circulation model forced only with the observed time-mean diabatic forcing as a constant forcing. Remarkably, despite the total neglect of all forcing variations, the model reproduces most features of the observed circulation variability and the mean climate, with biases similar to those of some state-of-the-art general circulation models. In particular, the spatial structures of the circulation variability are remarkably well reproduced. Their amplitudes, however, are progressively underestimated from the synoptic to the subseasonal to interannual and longer time scales. This underestimation is attributed to the neglect of the variable forcing. The model also excites significant tropical variability from the extratropics on interannual scales, which is overwhelmed in reality by the response to tropical heating variability. It is argued that the results of this study suggest a role for the stochastic, and not only the coherent, components of transient diabatic forcing in the dynamics of climate variability and the mean climate.","book_title":"","series":"","published_year":"2007","published_month":"12","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"23","pagerange":"5677-5695","doi":"10.1175\/2007JCLI1411.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5342","last_name":"Sardeshmukh","first_name":"","first_name_abbr":"P. D.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5501","last_name":"Sura","first_name":"","first_name_abbr":"P.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[]},{"id":"19302","title":"CloudSat spaceborne 94 GHz radar bright bands in the melting layer: An attenuation-driven upside-down lidar analog","abstract":"The CloudSat satellite supports a W-band (94 GHz) cloud profiling radar. At this 3.2 mm wavelength, ground-based measurements of rainfall associated with melting snowflakes do not show the radar reflectivity peak that is characteristic of bright band measurements at longer (Rayleigh scattering-dominated) wavelengths. Nonetheless, examination of downward-looking CloudSat returns in precipitation often indicate an obvious signal peak in the melting region. Through melting layer microphysical and scattering model simulations, we demonstrate that this downward-viewing radar feature is analogous to the lidar bright band observed from the ground in that it owes its existence to strong attenuation. In the upward-looking lidar case, the strong attenuation comes from large low-density snowflakes. In the downward-looking 94 GHz radar case, it is due to the effects of the greater refractive index of water particles compared to ice: it is comparable to an upside-down lidar bright band. A W-band radar dark band, which contributes to the visibility of the bright band, is shown to be due to attenuation in the snowfall. For comparison, the bright and dark bands for an upward viewing lidar are also modeled: the latter is simulated by a reduction in light backscattering efficiency of ice-containing raindrops.","book_title":"","series":"","published_year":"2007","published_month":"8","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L16818","doi":"10.1029\/2007GL030291","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5489","last_name":"Sassen","first_name":"","first_name_abbr":"K.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5985","last_name":"Matrosov","first_name":"","first_name_abbr":"S.","orcid":"","pos":"1","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5986","last_name":"Campbell","first_name":"","first_name_abbr":"J.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19303","title":"HEPEX: The Hydrological Ensemble Prediction Experiment","abstract":"The Hydrological Ensemble Prediction Experiment (HEPEX) is an international project to advance technologies for hydrological forecasting. Its goal is \u201cto bring the international hydrological and meteorological communities together to demonstrate how to produce and utilize reliable hydrological ensemble forecasts to make decisions for the benefit of public health and safety, the economy, and the environment.\u201d HEPEX is an open group composed primarily of researchers, forecasters, water managers, and users. HEPEX welcomes new members.\r\n\r\nIn the first workshop, held in the spring of 2004, HEPEX participants formulated scientific questions that, once addressed, should help produce valuable hydrological ensemble prediction to serve users' needs. During the second HEPEX workshop, held in the summer of 2005, a series of coordinated test-bed demonstration projects was set up as a method for answering these questions. The test beds are collections of data and models for specific hydrological basins or subbasins, where relevant meteorological and hydrological data have been archived. The test beds will facilitate the intercomparison of various hydrological prediction methods and linkages to users. The next steps for HEPEX are to complete the work planned for each test bed and to use the results to engineer more valuable automated hydrological prediction systems.","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"10","pagerange":"1541-1547","doi":"10.1175\/BAMS-88-10-1541","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5987","last_name":"Schaake","first_name":"","first_name_abbr":"J. C.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5988","last_name":"Buizza","first_name":"","first_name_abbr":"R.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5989","last_name":"Clark","first_name":"","first_name_abbr":"M.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19304","title":"Wind Profiler Observations over the Central Equatorial Pacific: Optimizing Processing to Improve Quality and Height Coverage","abstract":"UHF (boundary layer) and VHF (troposphere\u2013stratosphere) wind profilers have operated at Christmas Island (2\u00b0N, 157\u00b0W) in the central equatorial Pacific from 1986 to 2002. Observed profiles of winds are sparse over the tropical oceans, but these are critical for understanding convective organization and the interaction of convection and waves. While the zonal winds below about 10 km have previously shown good agreement with the National Centers for Environmental Prediction\u2013National Center for Atmospheric Research (NCEP\u2013NCAR) reanalysis (RI), significant differences were found above a height of 10 km that were attributed to the low detectability of the wind signal in the profiler observations. Meridional winds at all levels show less agreement, with differences attributed to errors of representativeness and the sparseness of observations in the region. This paper builds on previous work using the Christmas Island wind profilers and presents the results of reprocessing the 17-yr profiler record with techniques that enhance the detectability of the signal at upper heights. The results are compared with nearby rawinsonde soundings obtained during a special campaign at Christmas Island and the RI, NCEP\u2013Department of Energy (DOE) reanalysis (RII), and the 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40). The newly processed profiler zonal and meridional wind observations show good agreement with rawinsonde observations from 0.5 to 19 km above sea level, with difference statistics similar to other studies. There is also significant improvement in the agreement of RI and RII reanalysis and profiler upper-level zonal and meridional winds from previous studies. A comparison of RII and ERA-40 reanalysis shows that difference statistics between the reanalyses are similar in magnitude to differences between the profiler and the individual reanalyses.","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"J. Atmos. Oceanic Technol.","publisher":"","pages":"0","place_of_pub":"","volume":"24","number":"10","pagerange":"1710-1725","doi":"10.1175\/JTECH2072.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5674","last_name":"Schafer","first_name":"","first_name_abbr":"R.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5670","last_name":"Avery","first_name":"","first_name_abbr":"S. K.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5990","last_name":"Gage","first_name":"","first_name_abbr":"K. S.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"5","short_name":"PSD1","type":"other"},{"creator_id":"5611","last_name":"Kiladis","first_name":"","first_name_abbr":"G. N.","orcid":"","pos":"3","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19305","title":"Retrieval of effective radius and liquid water path from ground-based instruments: A case study at Barrow, Alaska","abstract":"Two methods for retrieving cloud droplet effective radius re from ground-based near-infrared spectral measurements of path-integrated liquid water paths (PLWPs) are described. In one method the PLWP is compared with column measurements of liquid water path (LWP) from a dual channel microwave radiometer (MWR) to estimate the cloud path enhancement, which is then used to derive the cloud droplet effective radius. In the second method, PLWP is combined with absolutely calibrated zenith radiances at 500 nm to retrieve re and LWP simultaneously. Both techniques are used in a case study of marine stratocumulus at the Barrow, Alaska (71.32\u00b0N, 156.62\u00b0W) Atmospheric Radiation Measurement Program (ARM) site on 17 September 2004. The first method performed best for moderately thick clouds (LWP \u2265 100 g m\u22122), but the accuracy is limited by uncertainties in the MWR LWP on which it relies. The second method performed well over a wider range of values with 1\u03c3 retrieval errors of <4 g m\u22122 (\u223c4%) and \u223c3 \u03bcm (\u223c7%) for 15 \u2264 LWP \u2264 170 g m\u22122. The LWPs retrieved using the radiance-PLWP method were highly correlated (r2 = 0.96) with LWPs from the MWR (with a bias subtracted) derived using the ARM statistical method. A limited comparison (LWP < 100 g m\u22122) to millimeter wave cloud radar showed that values of re retrieved using the radiance-PLWP method were consistently higher (by \u223c3 \u03bcm) than the LWC-weighted mean re from the radar. Additional field studies are needed to resolve this discrepancy, although this first comparison is promising.","book_title":"","series":"","published_year":"2007","published_month":"11","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D21203","doi":"10.1029\/2007JD008737","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5586","last_name":"Schofield","first_name":"","first_name_abbr":"R.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5580","last_name":"Daniel","first_name":"","first_name_abbr":"J. S.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5437","last_name":"Shupe","first_name":"","first_name_abbr":"M. D.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19306","title":"Predicting Drought on Seasonal-to-Decadal Time Scales","abstract":"N\/A","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"10","pagerange":"1625-1630","doi":"10.1175\/BAMS-88-10-1625","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5991","last_name":"Schubert","first_name":"","first_name_abbr":" S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5992","last_name":"Koster","first_name":"","first_name_abbr":"R.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5339","last_name":"Hoerling","first_name":"","first_name_abbr":"M. P.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5993","last_name":"Seager","first_name":"","first_name_abbr":"R.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5641","last_name":"Lettenmaier","first_name":"","first_name_abbr":"D.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5337","last_name":"Kumar","first_name":"","first_name_abbr":"A.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5635","last_name":"Gutzler","first_name":"","first_name_abbr":"D.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19307","title":"Supplement to Predicting Drought on Seasonal-to-Decadal Time Scales: A National Drought Attribution and Prediction Consortium","abstract":"N\/A","book_title":"","series":"","published_year":"2007","published_month":"10","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"10","pagerange":"S9-S10","doi":"10.1175\/BAMS-88-10-Schubert","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5652","last_name":"Schubert","first_name":"","first_name_abbr":"S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5992","last_name":"Koster","first_name":"","first_name_abbr":"R.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5339","last_name":"Hoerling","first_name":"","first_name_abbr":"M. P.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5993","last_name":"Seager","first_name":"","first_name_abbr":"R.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5641","last_name":"Lettenmaier","first_name":"","first_name_abbr":"D.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5337","last_name":"Kumar","first_name":"","first_name_abbr":"A.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5635","last_name":"Gutzler","first_name":"","first_name_abbr":"D.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19308","title":"Sub-seasonal variance of surface meteorological parameters in buoy observations and reanalyses","abstract":"Tropical Atmosphere Ocean (TAO)\/Triangle Trans-Ocean Buoy Network (TRITON) and Eastern Pacific Investigation of Climate (EPIC) moorings across the equatorial Pacific are used to evaluate the mean climate and sub-seasonal variance in surface meteorological variables in the NCEP\/NCAR, NCEP\/DOE, and ERA40 reanalyses. This study focuses on the June\u2013November time period when tropical storms are most frequent in the region. For the mean fields, the reanalysis surface products compare better with the moorings than the 1000 hPa products. In contrast, the variance in the 1000 hPa ERA40 state variables is in best agreement with the mooring variance. As long as these disparities exist, air-sea interaction studies and our ability to drive ocean models with observed fluxes will be limited.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L12708","doi":"10.1029\/2007GL029506","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5994","last_name":"Serra","first_name":"","first_name_abbr":"Y. L.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5577","last_name":"Cronin","first_name":"","first_name_abbr":"M. F.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5611","last_name":"Kiladis","first_name":"","first_name_abbr":"G. N.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19309","title":"A ground-based multiple remote-sensor cloud phase classifier","abstract":"A method for classifying cloud phase from a suite of ground-based sensors is outlined. The method exploits the complementary strengths of cloud radar, depolarization lidar, microwave radiometer, and temperature soundings to classify clouds observed in the vertical column as ice, snow, mixed-phase, liquid, drizzle, rain, or aerosol. Although the classification has been specifically designed for observations of Arctic clouds, the general framework is applicable to other locations with minor modifications. An example classification demonstrates the application to actual measurements.","book_title":"","series":"","published_year":"2007","published_month":"11","publication":"Geophys. Res. Lett.","publisher":"","pages":"0","place_of_pub":"","volume":"34","number":"","pagerange":"L22809","doi":"10.1029\/2007GL031008","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5437","last_name":"Shupe","first_name":"","first_name_abbr":"M. D.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"}],"editors":[]},{"id":"19311","title":"Bottom-up forcing and the decline of Steller sea lions (Eumetopias jubatas) in Alaska: assessing the ocean climate hypothesis","abstract":"Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976\u201377 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affected the rates of birth and death of sea lions. Recent studies of the spatial and temporal variations in the ocean climate system of the North Pacific support this hypothesis. Ocean climate changes appear to have created adaptive opportunities for various species that are preyed upon by Steller sea lions at mid-trophic levels. The east\u2013west asymmetry of the oceanic response to climate forcing after 1976\u201377 is consistent with both the temporal aspect (populations decreased after the late 1970s) and the spatial aspect of the decline (western, but not eastern, sea lion populations decreased). These broad-scale climate variations appear to be modulated by regionally sensitive biogeographic structures along the Aleutian Islands and Gulf of Alaska, which include a transition point from coastal to open-ocean conditions at Samalga Pass westward along the Aleutian Islands. These transition points delineate distinct clusterings of different combinations of prey species, which are in turn correlated with differential population sizes and trajectories of Steller sea lions. Archaeological records spanning 4000 yr further indicate that sea lion populations have experienced major shifts in abundance in the past. Shifts in ocean climate are the most parsimonious underlying explanation for the broad suite of ecosystem changes that have been observed in the North Pacific Ocean in recent decades.","book_title":"","series":"","published_year":"2007","published_month":"1","publication":"Fish. Oceanogr.","publisher":"","pages":"0","place_of_pub":"","volume":"16","number":"1","pagerange":"46-67","doi":"10.1111\/j.1365-2419.2006.00408.x","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5997","last_name":"Trites","first_name":"","first_name_abbr":"A. W.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5361","last_name":"Miller","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5855","last_name":". .","first_name":"","first_name_abbr":".","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5358","last_name":"Alexander","first_name":"","first_name_abbr":"M. A.","orcid":"","pos":"3","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19312","title":"Vertical-Mode and Cloud Decomposition of Large-Scale Convectively Coupled Gravity Waves in a Two-Dimensional Cloud-Resolving Model","abstract":"This paper describes an analysis of large-scale [O(1000 km)] convectively coupled gravity waves simulated using a two-dimensional cloud-resolving model. The waves develop spontaneously under uniform radiative cooling and approximately zero-mean-flow conditions, with wavenumber 2 of the domain appearing most prominently and right-moving components dominating over left-moving components for random reasons. The analysis discretizes the model output in two ways. First, a vertical-mode transform projects profiles of winds, temperature, and heating onto the vertical modes of the model\u2019s base-state atmosphere. Second, a cloud-partitioning algorithm sorts sufficiently cloudy grid columns into three categories: shallow convective, deep convective, and stratiform anvil.\r\n\r\nResults show that much of the tilted structures of the waves can be captured by just two main vertical spectral \u201cbands,\u201d each consisting of a pair of vertical modes. The \u201cslow\u201d modes have propagation speeds of 16 and 18 m s\u22121 (and roughly a full-wavelength vertical structure through the troposphere), while the \u201cfast\u201d modes have speeds of 35 and 45 m s\u22121 (and roughly a half-wavelength structure). Deep convection anomalies in the waves are more or less in phase with the low-level cold temperature anomalies of the slow modes and in quadrature with those of the fast modes. Owing to the characteristic life cycle of deep convective cloud systems, shallow convective heating peaks 2 h prior to maximum deep convective heating, while stratiform heating peaks 3 h after. The onset of deep convection in the waves is preceded by a gradual deepening of shallow convection lasting a period of many hours.\r\n\r\nResults of this study are in broad agreement with simple two-mode models of unstable large-scale wave growth, under the name \u201cstratiform instability.\u201d Differences here are that 1) the key dynamical modes have speeds in the range 16\u201318 m s\u22121, rather than 23\u201325 m s\u22121 (owing to a shallower depth of imposed radiative cooling), and 2) deep convective heating, as well as stratiform heating, is essential for the generation and maintenance of the slow modes.","book_title":"","series":"","published_year":"2007","published_month":"4","publication":"J. Atmos. Sci.","publisher":"","pages":"0","place_of_pub":"","volume":"64","number":"4","pagerange":"1210-1229","doi":"10.1175\/JAS3884.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5998","last_name":"Tulich","first_name":"","first_name_abbr":"S. N.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5999","last_name":"Randall","first_name":"","first_name_abbr":"D. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5422","last_name":"Mapes","first_name":"","first_name_abbr":"B. E.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19313","title":"Thin Liquid Water Clouds: Their Importance and Our Challenge","abstract":"Many of the clouds important to the Earth's energy balance, from the Tropics to the Arctic, contain small amounts of liquid water. Longwave and shortwave radiative fluxes are very sensitive to small perturbations of the cloud liquid water path (LWP), when the LWP is small (i.e., < 100 g m\u22122; clouds with LWP less than this threshold will be referred to as \u201cthin\u201d). Thus, the radiative properties of these thin liquid water clouds must be well understood to capture them correctly in climate models. We review the importance of these thin clouds to the Earth's energy balance, and explain the difficulties in observing them. In particular, because these clouds are thin, potentially mixed phase, and often broken (i.e., have large 3D variability), it is challenging to retrieve their microphysical properties accurately. We describe a retrieval algorithm intercomparison that was conducted to evaluate the issues involved. The intercomparison used data collected at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site and included 18 different algorithms to evaluate their retrieved LWP, optical depth, and effective radii. Surprisingly, evaluation of the simplest case, a single-layer overcast stratocumulus, revealed that huge discrepancies exist among the various techniques, even among different algorithms that are in the same general classification. This suggests that, despite considerable advances that have occurred in the field, much more work must be done, and we discuss potential avenues for future research.)","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"2","pagerange":"177-190","doi":"10.1175\/BAMS-88-2-177","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5853","last_name":"Turner","first_name":"","first_name_abbr":"D. D.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6000","last_name":"Vogelmann","first_name":"","first_name_abbr":"A. M.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6001","last_name":"Austin","first_name":"","first_name_abbr":"R. T.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6002","last_name":"Barnard","first_name":"","first_name_abbr":"J. C.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6003","last_name":"Cady-Pereira","first_name":"","first_name_abbr":"K. ","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6004","last_name":"Chiu","first_name":"","first_name_abbr":"J. C.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6005","last_name":"Clough","first_name":"","first_name_abbr":"S. A.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6006","last_name":"Flynn","first_name":"","first_name_abbr":"C.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6007","last_name":"Khaiyer","first_name":"","first_name_abbr":"M. M.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6008","last_name":"Liljegren","first_name":"","first_name_abbr":"J.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6009","last_name":"Johnson","first_name":"","first_name_abbr":"K.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6010","last_name":"Lin","first_name":"","first_name_abbr":"B.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6011","last_name":"Long","first_name":"","first_name_abbr":"C.","orcid":"","pos":"12","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5352","last_name":"Marshak","first_name":"","first_name_abbr":"A.","orcid":"","pos":"13","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5398","last_name":"Matrosov","first_name":"","first_name_abbr":"S. Y.","orcid":"","pos":"14","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5851","last_name":"McFarlane","first_name":"","first_name_abbr":"S. A.","orcid":"","pos":"15","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6012","last_name":"Miller","first_name":"","first_name_abbr":"M.","orcid":"","pos":"16","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6013","last_name":"Min","first_name":"","first_name_abbr":"Q.","orcid":"","pos":"17","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5480","last_name":"Minnis","first_name":"","first_name_abbr":"P.","orcid":"","pos":"18","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6014","last_name":"O'Hirok","first_name":"","first_name_abbr":"W. ","orcid":"","pos":"19","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5397","last_name":"Wang","first_name":"","first_name_abbr":"Z.","orcid":"","pos":"20","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6015","last_name":"Wiscombe","first_name":"","first_name_abbr":"W.","orcid":"","pos":"21","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19314","title":"Tomographic reconstruction of atmospheric turbulence with the use of time-dependent stochastic inversion","abstract":"Acoustic travel-time tomography allows one to reconstruct temperature and wind velocity fields in the atmosphere. In a recently published paper [ S. Vecherin et al., J. Acoust. Soc. Am. 119, 2579 (2006) ], a time-dependent stochastic inversion (TDSI) was developed for the reconstruction of these fields from travel times of sound propagation between sources and receivers in a tomography array. TDSI accounts for the correlation of temperature and wind velocity fluctuations both in space and time and therefore yields more accurate reconstruction of these fields in comparison with algebraic techniques and regular stochastic inversion. To use TDSI, one needs to estimate spatial-temporal covariance functions of temperature and wind velocity fluctuations. In this paper, these spatial-temporal covariance functions are derived for locally frozen turbulence which is a more general concept than a widely used hypothesis of frozen turbulence. The developed theory is applied to reconstruction of temperature and wind velocity fields in the acoustic tomography experiment carried out by University of Leipzig, Germany. The reconstructed temperature and velocity fields are presented and errors in reconstruction of these fields are studied.","book_title":"","series":"","published_year":"2007","published_month":"9","publication":"J. Acoust. Soc. Am.","publisher":"","pages":"0","place_of_pub":"","volume":"122","number":"3","pagerange":"1416-1425","doi":"10.1121\/1.2756798","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5769","last_name":"Vecherin","first_name":"","first_name_abbr":"S. N.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5443","last_name":"Ostashev","first_name":"","first_name_abbr":"V. E.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19315","title":"The Mixed-Phase Arctic Cloud Experiment","abstract":"The Mixed-Phase Arctic Cloud Experiment (M-PACE) was conducted from 27 September through 22 October 2004 over the Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) on the North Slope of Alaska. The primary objectives were to collect a dataset suitable to study interactions between microphysics, dynamics, and radiative transfer in mixed-phase Arctic clouds, and to develop\/evaluate cloud property retrievals from surface- and satellite-based remote sensing instruments. Observations taken during the 1977\/98 Surface Heat and Energy Budget of the Arctic (SHEBA) experiment revealed that Arctic clouds frequently consist of one (or more) liquid layers precipitating ice. M-PACE sought to investigate the physical processes of these clouds by utilizing two aircraft (an in situ aircraft to characterize the microphysical properties of the clouds and a remote sensing aircraft to constraint the upwelling radiation) over the ACRF site on the North Slope of Alaska. The measurements successfully documented the microphysical structure of Arctic mixed-phase clouds, with multiple in situ profiles collected in both single- and multilayer clouds over two ground-based remote sensing sites. Liquid was found in clouds with cloud-top temperatures as cold as \u221230\u00b0C, with the coldest cloud-top temperature warmer than \u221240\u00b0C sampled by the aircraft. Remote sensing instruments suggest that ice was present in low concentrations, mostly concentrated in precipitation shafts, although there are indications of light ice precipitation present below the optically thick single-layer clouds. The prevalence of liquid down to these low temperatures potentially could be explained by the relatively low measured ice nuclei concentrations.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Bull. Amer. Meteor. Soc.","publisher":"","pages":"0","place_of_pub":"","volume":"88","number":"2","pagerange":"205-221","doi":"10.1175\/BAMS-88-2-205","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"6016","last_name":"Verlinde","first_name":"","first_name_abbr":"J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6017","last_name":"Harrington","first_name":"","first_name_abbr":"J. Y.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6018","last_name":"McFarquhar","first_name":"","first_name_abbr":"G. M.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6019","last_name":"Yannuzzi","first_name":"","first_name_abbr":"V. T.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6020","last_name":"Avramov","first_name":"","first_name_abbr":"A.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6021","last_name":"Greenberg","first_name":"","first_name_abbr":"S.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6022","last_name":"Johnson","first_name":"","first_name_abbr":"N.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6023","last_name":"Zhang","first_name":"","first_name_abbr":"G.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6024","last_name":"Poellot","first_name":"","first_name_abbr":"M. R.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6025","last_name":"Mather","first_name":"","first_name_abbr":"J. H.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5853","last_name":"Turner","first_name":"","first_name_abbr":"D. D.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6026","last_name":"Eloranta","first_name":"","first_name_abbr":"E. W.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6027","last_name":"Zak","first_name":"","first_name_abbr":"B. D.","orcid":"","pos":"12","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6028","last_name":"Prenni","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"13","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5580","last_name":"Daniel","first_name":"","first_name_abbr":"J. S.","orcid":"","pos":"14","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6029","last_name":"Kok","first_name":"","first_name_abbr":"G. L.","orcid":"","pos":"15","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6030","last_name":"Tobin","first_name":"","first_name_abbr":"D. C.","orcid":"","pos":"16","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6031","last_name":"Holz","first_name":"","first_name_abbr":"R.","orcid":"","pos":"17","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5489","last_name":"Sassen","first_name":"","first_name_abbr":"K.","orcid":"","pos":"18","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6032","last_name":"Spangenberg","first_name":"","first_name_abbr":"D.","orcid":"","pos":"19","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5480","last_name":"Minnis","first_name":"","first_name_abbr":"P.","orcid":"","pos":"20","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6033","last_name":"Tooman","first_name":"","first_name_abbr":"T. P.","orcid":"","pos":"21","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6034","last_name":"Ivey","first_name":"","first_name_abbr":"M. D.","orcid":"","pos":"22","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6035","last_name":"Richardson","first_name":"","first_name_abbr":"S. J.","orcid":"","pos":"23","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6036","last_name":"Bahrmann","first_name":"","first_name_abbr":"C. P.","orcid":"","pos":"24","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5437","last_name":"Shupe","first_name":"","first_name_abbr":"M. D.","orcid":"","pos":"25","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"6037","last_name":"DeMott","first_name":"","first_name_abbr":"P. J.","orcid":"","pos":"26","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5396","last_name":"Heymsfield","first_name":"","first_name_abbr":"A. J.","orcid":"","pos":"27","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5586","last_name":"Schofield","first_name":"","first_name_abbr":"R.","orcid":"","pos":"28","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19316","title":"Tangent plane approximation and some of its generalizations","abstract":"A review of the tangent plane approximation proposed by L.M. Brekhovskikh is presented. The advantage of the tangent plane approximation over methods based on the analysis of integral equations for surface sources is emphasized. A general formula is given for the scattering amplitude of scalar plane waves under an arbitrary boundary condition. The direct generalization of the tangent plane approximation is shown to yield approximations that include a correct description of the Bragg scattering and allow one to avoid the use of a two-scale model.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"Acoust. Phys.","publisher":"","pages":"0","place_of_pub":"","volume":"53","number":"3","pagerange":"298-304","doi":"10.1134\/S1063771007030062","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5507","last_name":"Voronovich","first_name":"","first_name_abbr":"A. G.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"}],"editors":[]},{"id":"19317","title":"A Comparison of Hybrid Ensemble Transform Kalman Filter\u2013Optimum Interpolation and Ensemble Square Root Filter Analysis Schemes","abstract":"A hybrid ensemble transform Kalman filter (ETKF)\u2013optimum interpolation (OI) analysis scheme is described and compared with an ensemble square root filter (EnSRF) analysis scheme. A two-layer primitive equation model was used under perfect-model assumptions. A simplified observation network was used, and the OI method utilized a static background error covariance constructed from a large inventory of historical forecast errors. The hybrid scheme updated the ensemble mean using a hybridized ensemble and static background-error covariance. The ensemble perturbations in the hybrid scheme were updated by the ETKF scheme. The EnSRF ran parallel data assimilation cycles for each member and serially assimilated the observations. The EnSRF background-error covariance was estimated fully from the ensemble.\r\n\r\nFor 50-member ensembles, the analyses from the hybrid scheme were as accurate or nearly as accurate as those from the EnSRF, depending on the norm. For 20-member ensembles, the analyses from the hybrid scheme were more accurate than analyses from the EnSRF under certain norms. Both hybrid and EnSRF analyses were more accurate than the analyses from the OI. Further reducing the ensemble size to five members, the EnSRF exhibited filter divergence, whereas the analyses from the hybrid scheme were still better than those updated by the OI. Additionally, the hybrid scheme was less prone to spurious gravity wave activity than the EnSRF, especially when the ensemble size was small. Maximal growth in the ETKF ensemble perturbation space exceeded that in the EnSRF ensemble perturbation space. The relationship of the ETKF ensemble variance to the analysis error variance, a measure of a spread\u2013skill relationship, was similar to that of the EnSRF ensemble. The hybrid scheme can be implemented in a reasonably straightforward manner in the operational variational frameworks, and the computational cost of the hybrid is expected to be much less than the EnSRF in the operational settings.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"3","pagerange":"1055-1076","doi":"10.1175\/MWR3307.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5788","last_name":"Wang","first_name":"","first_name_abbr":"X.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5395","last_name":"Whitaker","first_name":"","first_name_abbr":"J. S.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5787","last_name":"Bishop","first_name":"","first_name_abbr":"C. H.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19318","title":"On the Theoretical Equivalence of Differently Proposed Ensemble\u20133DVAR Hybrid Analysis Schemes","abstract":"Hybrid ensemble\u2013three-dimensional variational analysis schemes incorporate flow-dependent, ensemble-estimated background-error covariances into the three-dimensional variational data assimilation (3DVAR) framework. Typically the 3DVAR background-error covariance estimate is assumed to be stationary, nearly homogeneous, and isotropic. A hybrid scheme can be achieved by 1) directly replacing the background-error covariance term in the cost function by a linear combination of the original background-error covariance with the ensemble covariance or 2) through augmenting the state vector with another set of control variables preconditioned upon the square root of the ensemble covariance. These differently proposed hybrid schemes are proven to be equivalent. The latter framework may be a simpler way to incorporate ensemble information into operational 3DVAR schemes, where the preconditioning is performed with respect to the background term.","book_title":"","series":"","published_year":"2007","published_month":"1","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"1","pagerange":"222-227","doi":"10.1175\/MWR3282.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5788","last_name":"Wang","first_name":"","first_name_abbr":"X.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"},{"creator_id":"6038","last_name":"Snyder","first_name":"","first_name_abbr":"C.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19319","title":"A Synoptic\u2013Dynamic Model of Subseasonal Atmospheric Variability","abstract":"A global synoptic\u2013dynamic model (GSDM) of subseasonal variability is proposed to provide a framework for real-time weather\u2013climate monitoring and to assist with the preparation of medium-range (e.g., week 1\u20133) predictions. The GSDM is used with a regional focus over North America during northern winter. A case study introduces the time scales of the GSDM and illustrates two circulation transitions related to eastward-moving wave energy signals and their connection to remote tropical forcing. Global and zonal atmospheric angular momentum (AAM) is used to help define the synoptic evolution of the GSDM components and to link regional synoptic variations with physical processes like the global mountain and frictional torque. The core of the GSDM consists of four stages based on the Madden\u2013Julian oscillation (MJO) recurrence time. Additionally, extratropical behaviors including teleconnection patterns, baroclinic life cycles, and monthly oscillations provide intermediate and fast time scales that are combined with the quasi-oscillatory (30\u201370 day) MJO to define multiple time-\/space-scale linear relationships. A unique feature of the GSDM is its focus on global and regional circulation transitions and the related extreme weather events during periods of large global AAM tendency.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"2","pagerange":"449-474","doi":"10.1175\/MWR3293.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5897","last_name":"Weickmann","first_name":"","first_name_abbr":"K.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"6039","last_name":"Berry","first_name":"","first_name_abbr":"E.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19320","title":"Comparing the impact of meteorological variability on surface ozone during the NEAQS (2002) and ICARTT (2004) field campaigns","abstract":"This paper investigates linkages between weather, climate, and air quality that contributed to the large difference in the number of ozone exceedances encountered in the northeastern United States (U.S.) during 2002 and 2004. Major air quality research field campaigns were conducted in the northeast during July and August of each year. Both the 2002 New England Air Quality Study (NEAQS-02) and the International Consortium for Atmospheric Research on Transport and Transformation 2004 field study (ICARTT-04) had research components focused on regional air quality. The primary environmental difference between the two field campaigns was the underlying climatic conditions. The July\u2013August period in 2002 was much sunnier, warmer, and drier than normal. In contrast, the July\u2013August period in 2004 was cloudier, cooler, and much wetter than normal. We conclude that these extreme climatic conditions were the underlying cause for the significant difference in the number of ozone exceedances that occurred during NEAQS-02 and ICARTT-04. We rule out the impact of other meteorological processes as the primary cause of this difference. We gauge horizontal transport using surface and upper air wind observations collected on Appledore Island (ADI), off the coast of New Hampshire and Maine, along with back trajectories based solely on wind observations collected by profiler networks deployed for each study. The wind conditions that favor pollutant transport to the northeast were more prevalent in 2004 than in 2002, yet the number of ozone exceedances in 2004 was more than a factor of three less than in 2002. Neither was daytime boundary layer mixing the cause for this discrepancy. Unlike other parts of the U.S. where poor air quality is generally associated with shallow boundary layers, in New England the boundary layers were deeper on high-ozone days than on clean days because the same sunny, warm, and dry conditions that favor boundary layer ozone production also produce deeper boundary layers. Both field campaigns were synoptically active. Lulls in synoptic activity explained most of the high-ozone events observed in 2002, whereas even an extended lull in synoptic activity during the summer of 2004 did not produce a single high-ozone day.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D10S14","doi":"10.1029\/2006JD007590","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5856","last_name":"Darby","first_name":"","first_name_abbr":"L. S.","orcid":"","pos":"1","branch_id":"18","staff_type_id":"1","short_name":"NIDIS","type":"Federal"},{"creator_id":"5857","last_name":"Senff","first_name":"","first_name_abbr":"C. J.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5638","last_name":"King","first_name":"","first_name_abbr":"C. W. ","orcid":"","pos":"3","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5858","last_name":"Banta","first_name":"","first_name_abbr":"R. M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6040","last_name":"Koermer","first_name":"","first_name_abbr":"J.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5433","last_name":"Wilczak","first_name":"","first_name_abbr":"J. M.","orcid":"","pos":"6","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5440","last_name":"Neiman","first_name":"","first_name_abbr":"P. J.","orcid":"","pos":"7","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5551","last_name":"Angevine","first_name":"","first_name_abbr":"W. M.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5864","last_name":"Talbot","first_name":"","first_name_abbr":"R.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19321","title":"Upper-ocean thermal structure and heat content off the US West Coast during the 1997\u20131998 El Ni\u00f1o event based on AXBT and satellite altimetry data","abstract":"During the 1997\/1998 El Ni\u00f1o event, extensive oceanic temperature profiles were taken off the coast of California in January and February 1998 using Airborne Expendable Bathythermographs (AXBTs). These AXBT measurements are compared with altimetry-based upper-ocean temperature estimates using TOPEX and ERS satellite altimetry data. The altimetry-based temperature estimates are well correlated with the AXBT data, in particular when combining the two satellite data sets together to form a blended altimeter temperature estimate. Both the AXBT and altimetry data show that the nearshore coastal El Ni\u00f1o signal differed from that further offshore. The AXBT data show that near shore, the warm anomalies extended to much greater depths and had greater amplitude. A time series of the satellite-derived layer-averaged temperatures, averaged separately over the nearshore and offshore halves of the AXBT analysis domain, also shows a larger El Ni\u00f1o signal in the nearshore half. The role of local atmospheric forcing of the coastal oceanic temperature anomalies is analyzed using NCEP reanalysis and coastal upwelling data sets. The forcing terms include Ekman pumping, radiation, surface heat fluxes, precipitation, and alongshore wind stresses that drive coastal upwelling (expressed as a coastal downwelling index, CDI). The temperature forcing from all of the terms except the CDI anomalies are small. The CDI anomalies can explain most of the slowly varying temperature changes that occur near the coast during a two-year period spanning the El Ni\u00f1o event, as well as some of the larger amplitude, rapid (monthly) warming episodes that appear to be part of the El Ni\u00f1o signal. Several distinct rapid warming episodes, however, are not correlated with the CDI anomalies, and therefore we conclude that the nearshore El Ni\u00f1o signal originates from a combination of both a remote oceanic pathway and local atmospheric forcing.","book_title":"","series":"","published_year":"2007","published_month":"7","publication":"Prog. Oceanogr.","publisher":"","pages":"0","place_of_pub":"","volume":"74","number":"1","pagerange":"48-70","doi":"10.1016\/j.pocean.2007.02.006","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5433","last_name":"Wilczak","first_name":"","first_name_abbr":"J. M.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"6041","last_name":"Leben","first_name":"","first_name_abbr":"R. R.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6042","last_name":"McCollumb","first_name":"","first_name_abbr":"D. S.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19322","title":"Comparison of Ensemble-MOS Methods Using GFS Reforecasts","abstract":"Three recently proposed and promising methods for postprocessing ensemble forecasts based on their historical error characteristics (i.e., ensemble-model output statistics methods) are compared using a multidecadal reforecast dataset. Logistic regressions and nonhomogeneous Gaussian regressions are generally preferred for daily temperature, and for medium-range (6\u201310 and 8\u201314 day) temperature and precipitation forecasts. However, the better sharpness of medium-range ensemble-dressing forecasts sometimes yields the best Brier scores even though their calibration is somewhat worse. Using the long (15 or 25 yr) training samples that are available with these reforecasts improves the accuracy and skill of these probabilistic forecasts to levels that are approximately equivalent to gains of 1 day of lead time, relative to using short (1 or 2 yr) training samples.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"Mon. Wea. Rev.","publisher":"","pages":"0","place_of_pub":"","volume":"135","number":"6","pagerange":"2379-2390","doi":"10.1175\/MWR3402.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"6043","last_name":"Wilks","first_name":"","first_name_abbr":"D. S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5386","last_name":"Hamill","first_name":"","first_name_abbr":"T. M.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"}],"editors":[]},{"id":"19323","title":"Chemical speciation of organic aerosol during the International Consortium for Atmospheric Research on Transport and Transformation 2004: Results from in situ measurements","abstract":"We report the first ever hourly in situ measurements of speciated organic aerosol composition. Measurements were made during July and August 2004 at Chebogue Point, Nova Scotia, using a novel thermal desorption aerosol GC\/MS-FID (TAG) instrument as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT). Hourly time resolution measurements of organic marker compounds were used to define several different source types contributing to the aerosols observed, including two aged anthropogenic sources from the United States, oxidized biogenic aerosols from Maine and Canada, local biogenic contributions to secondary organic aerosol (SOA), local anthropogenic contributions to hydrocarbon-like organic aerosol (HOA), and a potential marine or dairy source. These TAG-defined sources were used to separate aerosol mass spectrometer (AMS) measurements of total organics, SO42\u2212, NO3\u2212, and NH4+, along with total aerosol black carbon (BC) into several distinct particle types. Average organic aerosol mass ranged from 33% of the total aerosol mass during anthropogenic U.S. outflow events to 81% of total aerosol mass during biogenic oxidation events arriving from Maine and Canada during 26 July to 15 August 2004.","book_title":"","series":"","published_year":"2007","published_month":"3","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D10S26","doi":"10.1029\/2006JD007601","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5709","last_name":"Williams","first_name":"","first_name_abbr":"B. J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5707","last_name":"Goldstein","first_name":"","first_name_abbr":"A. H.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5706","last_name":"Millet","first_name":"","first_name_abbr":"D. B.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5708","last_name":"Holzinger","first_name":"","first_name_abbr":"R.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6044","last_name":"Kreisberg","first_name":"","first_name_abbr":"N. M.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6045","last_name":"Hering","first_name":"","first_name_abbr":"S. V.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"6","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"},{"creator_id":"5712","last_name":"Worsnop","first_name":"","first_name_abbr":"D. R.","orcid":"","pos":"7","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5710","last_name":"Allan","first_name":"","first_name_abbr":"J. D.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5711","last_name":"Jimenez","first_name":"","first_name_abbr":"J. L.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19324","title":"Vertical Structure of Precipitation and Related Microphysics Observed by NOAA Profilers and TRMM during NAME 2004","abstract":"In support of the 2004 North American Monsoon Experiment (NAME) field campaign, NOAA established and maintained a field site about 100 km north of Mazatl\u00e1n, Mexico, consisting of wind profilers, precipitation profilers, surface upward\u2013downward-looking radiometers, and a 10-m meteorological tower to observe the environment within the North American monsoon. Three objectives of this NOAA project are discussed in this paper: 1) to observe the vertical structure of precipitating cloud systems as they passed over the NOAA profiler site, 2) to estimate the vertical air motion and the raindrop size distribution from near the surface to just below the melting layer, and 3) to better understand the microphysical processes associated with stratiform rain containing well-defined radar bright bands.\r\n\r\nTo provide a climatological context for the profiler observations at the field site, the profiler reflectivity distributions were compared with Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) reflectivity distributions from the 2004 season over the NAME domain as well as from the 1998\u20132005 seasons. This analysis places the NAME 2004 observations into the context of other monsoon seasons. It also provides a basis for evaluating the representativeness of the structure of the precipitation systems sampled at this location. The number of rain events observed by the TRMM PR is dependent on geography; the land region, which includes portions of the Sierra Madre Occidental, has more events than the coast and gulf regions. Conversely, from this study it is found that the frequencies of occurrence of stratiform rain and reflectivity profiles with radar bright bands are mostly independent of region. The analysis also revealed that the reflectivity distribution at each height has more year-to-year variability than region-to-region variability. These findings suggest that in cases with a well-defined bright band, the vertical profile of the reflectivity relative to the height of the bright band is similar over the gulf, coast, and land regions.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"9","pagerange":"1693-1712","doi":"10.1175\/JCLI4102.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5493","last_name":"Williams","first_name":"","first_name_abbr":"C. R. ","orcid":"","pos":"0","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"1","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5990","last_name":"Gage","first_name":"","first_name_abbr":"K. S.","orcid":"","pos":"2","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5373","last_name":"Ralph","first_name":"","first_name_abbr":"F. M.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"1","short_name":"PSD2","type":"Federal"}],"editors":[]},{"id":"19325","title":"Time-domain calculations of sound interactions with outdoor ground surfaces","abstract":"A time-domain formulation for sound propagation in rigid-frame porous media, including waveform attenuation and dispersion, is developed. The new formulation is based on inversion of the relaxation functions from a previous model [Wilson DK, Ostashev VE, Collier SL. J Acoust Soc Am 2004;116:1889\u201392], thereby casting the convolution integrals in a form amenable to numerical implementation. Numerical techniques are developed that accurately implement the relaxational equations and transparently reduce to previous results in low- and high-frequency limits. The techniques are demonstrated on calculations of outdoor sound propagation involving hills, barriers, and ground surfaces with various material properties. We also compare the relaxation formulation to a widely applied phenomenological model developed by Zwikker and Kosten. The two models can be made equivalent if the resistance constant, structure constant, and compression modulus in the ZK model are allowed to be weakly frequency dependent. But if the ZK parameters are taken to be constant, as is typically the case, the relaxation model provides more accurate calculations of attenuation by acoustically soft porous materials such as snow, gravel, and forest litter.","book_title":"","series":"","published_year":"2007","published_month":"2","publication":"Appl. Acoust.","publisher":"","pages":"0","place_of_pub":"","volume":"68","number":"","pagerange":"173-200","doi":"10.1016\/j.apacoust.2005.10.004","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5445","last_name":"Wilson","first_name":"","first_name_abbr":"D. K.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5443","last_name":"Ostashev","first_name":"","first_name_abbr":"V. E.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5356","last_name":"al.","first_name":"","first_name_abbr":"et","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19326","title":"Shipboard multisensor merged wind profiles from the New England Air Quality Study 2004","abstract":"The New England Air Quality Study (NEAQS) was a regional portion of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) planned by groups in North America and Europe to develop a better understanding of the factors that shape air quality in their respective regions and the remote North Atlantic. The NOAA research vessel Ronald H. Brown was only one of a number of platforms given the task of monitoring the emissions of aerosol and ozone precursors and the atmosphere in which they reside. Two remote and one in situ sensor were used to measure wind profiles. A radar wind profiler (RWP) permanently deployed on the ship and corrected in real time for ship motion provided continuous hourly profiles at 60- and 100-m vertical resolutions. A high-resolution Doppler lidar (HRDL) was also operated during the experiment and provided continuous low-level wind profiles. Rawinsondes were launched 4\u20136 times daily and provided a detailed profile of winds. Initial results show that the RWP, HRDL, and rawinsonde data compare very well. The ability of HRDL to monitor low-level winds below the minimum range gate of the RWP, while the RWP wind data extend to a much greater height than can be reached by HRDL, make the two systems complementary. Single merged profiles were generated using the RWP and HRDL data, which in turn were used to calculate trajectories to help better understand the transport of pollutants within the Gulf of Maine.","book_title":"","series":"","published_year":"2007","published_month":"4","publication":"J. Geophys. Res. Atmos.","publisher":"","pages":"0","place_of_pub":"","volume":"112","number":"","pagerange":"D10S15","doi":"10.1029\/2006JD007344","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5834","last_name":"Wolfe","first_name":"","first_name_abbr":"D. E.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5553","last_name":"Brewer","first_name":"","first_name_abbr":"W. A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5602","last_name":"Tucker","first_name":"","first_name_abbr":"S. C.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5442","last_name":"White","first_name":"","first_name_abbr":"A. B.","orcid":"","pos":"3","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"5794","last_name":"White","first_name":"","first_name_abbr":"D. E.","orcid":"","pos":"4","branch_id":"22","staff_type_id":"2","short_name":"PSD2","type":"CIRES"},{"creator_id":"6046","last_name":"Welsh","first_name":"","first_name_abbr":"D. C.","orcid":"","pos":"5","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"6047","last_name":"Ruffieux","first_name":"","first_name_abbr":"D.","orcid":"","pos":"6","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"7","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"6048","last_name":"Ratterree","first_name":"","first_name_abbr":"M.","orcid":"","pos":"8","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5537","last_name":"Intrieri","first_name":"","first_name_abbr":"J. M.","orcid":"","pos":"9","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6049","last_name":"McCarty","first_name":"","first_name_abbr":"B. J.","orcid":"","pos":"10","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6050","last_name":"Law","first_name":"","first_name_abbr":"D. C.","orcid":"","pos":"11","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19328","title":"On Air\u2013Sea Interaction at the Mouth of the Gulf of California","abstract":"Surface flux, wind profiler, oceanic temperature and salinity, and atmospheric moisture, cloud, and wind observations gathered from the R\/V Altair during the North American Monsoon Experiment (NAME) are presented. The vessel was positioned at the mouth of the Gulf of California halfway between La Paz and Mazatlan (23.5\u00b0N, 108\u00b0W), from 7 July to 11 August 2004, with a break from 22 to 27 July. Experiment-mean findings include a net heat input from the atmosphere into the ocean of 70 W m\u22122. The dominant cooling was an experiment-mean latent heat flux of 108 W m\u22122, equivalent to an evaporation rate of 0.16 mm h\u22121. Total accumulated rainfall amounted to 42 mm. The oceanic mixed layer had a depth of approximately 20 m and both warmed and freshened during the experiment, despite a dominance of evaporation over local precipitation. The mean atmospheric boundary layer depth was approximately 410 m, deepening with time from an initial value of 350 m. The mean near-surface relative humidity was 66%, increasing to 73% at the top of the boundary layer. The rawinsondes documented an additional moist layer between 2- and 3-km altitude associated with a land\u2013sea breeze, and a broad moist layer at 5\u20136 km associated with land-based convective outflow. The observational period included a strong gulf surge around 13 July associated with the onset of the summer monsoon in southern Arizona. During this surge, mean 1000\u2013700-hPa winds reached 12 m s\u22121, net surface fluxes approached zero, and the atmosphere moistened significantly but little rainfall occurred. The experiment-mean wind diurnal cycle was dominated by mainland Mexico and consisted of a near-surface westerly sea breeze along with two easterly return flows, one at 2\u20133 km and another at 5\u20136 km. Each of these altitudes experienced nighttime cloudiness. The corresponding modulation of the radiative cloud forcing diurnal cycle provided a slight positive feedback upon the sea surface temperature. Two findings were notable. One was an advective warming of over 1\u00b0C in the oceanic mixed layer temperature associated with the 13 July surge. The second was the high nighttime cloud cover fraction at 5\u20136 km, dissipating during the day. These clouds appeared to be thin, stratiform, slightly supercooled liquid-phase clouds. The preference for the liquid phase increases the likelihood that the clouds can be advected farther from their source and thereby contribute to a higher-altitude horizontal moisture flux into the United States.","book_title":"","series":"","published_year":"2007","published_month":"5","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"9","pagerange":"1649-1661","doi":"10.1175\/JCLI4089.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"5438","last_name":"Zuidema","first_name":"","first_name_abbr":"P.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5382","last_name":"Fairall","first_name":"","first_name_abbr":"C. W.","orcid":"","pos":"1","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"6056","last_name":"Hartten","first_name":"","first_name_abbr":"L. M.","orcid":"","pos":"2","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5457","last_name":"Hare","first_name":"","first_name_abbr":"J. E.","orcid":"","pos":"3","branch_id":"23","staff_type_id":"2","short_name":"PSD3","type":"CIRES"},{"creator_id":"5552","last_name":"Wolfe","first_name":"","first_name_abbr":"D.","orcid":"","pos":"4","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"}],"editors":[]},{"id":"19329","title":"What maintains the SST front north of the eastern Pacific equatorial cold tongue?","abstract":"A coupled ocean\u2013atmosphere regional model suggests a mechanism for formation of a sharp sea surface temperature (SST) front north of the equator in the eastern Pacific Ocean in boreal summer and fall. Meridional convergence of Ekman transport at 5\u00b0N is forced by eastward turning of the southeasterly cross-equatorial wind, but the SST front forms considerably south of the maximum Ekman convergence. Geostrophic equatorward flow at 3\u00b0N in the lower half of the isothermally mixed layer enhances mixed layer convergence.\r\n\r\nCold water is upwelled on or south of the equator and is advected poleward by mean mixed layer flow and by eddies. The mixed layer current convergence in the north confines the cold advection, so the SST front stays close to the equator. Warm advection from the north and cold advection from the south strengthen the front. In the Southern Hemisphere, a continuous southwestward current advects cold water far from the upwelling core.\r\n\r\nThe cold tongue is warmed by the net surface flux, which is dominated by solar radiation. Evaporation and net surface cooling are at a maximum just north of the SST front where relatively cool dry air is advected northward over warm SST. The surface heat flux is decomposed into a response to SST alone, and an atmospheric feedback. The atmospheric feedback enhances cooling on the north side of the front by 178 W m\u22122, about half of which is due to enhanced evaporation from cold dry advection, while the other half is due to cloud radiative forcing.","book_title":"","series":"","published_year":"2007","published_month":"6","publication":"J. Climate","publisher":"","pages":"0","place_of_pub":"","volume":"20","number":"11","pagerange":"2500-2514","doi":"10.1175\/JCLI4173.1","isbn":"","official_url":"","pub_type_id":"1","type":"Article","pub_status_id":"3","authors":[{"creator_id":"6057","last_name":"de Szoeke","first_name":"","first_name_abbr":"S. P.","orcid":"","pos":"0","branch_id":"22","staff_type_id":"5","short_name":"PSD2","type":"other"},{"creator_id":"6058","last_name":"Xie","first_name":"","first_name_abbr":"S.-P.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6059","last_name":"Miyama","first_name":"","first_name_abbr":"T.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6060","last_name":"Richards","first_name":"","first_name_abbr":"K. J.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"6061","last_name":"Small","first_name":"","first_name_abbr":"R. J. O.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[]},{"id":"19310","title":"The Role of El Ni\u00f1o\u2014Southern Oscillation in Regulating its Background State","abstract":"A nonlinear aspect of the El Ni\u00f1o\u2014Southern Oscillation (ENSO)\u2014its regulatory effect on the background state (the climatological state)\u2014is described. In particular, it is shown that ENSO acts as a basin-scale heat \u201cmixer\u201d that prevents any significant increase from occurring in the time-mean difference between the warm-pool SST (Tw) and the temperature of the thermocline water (Tc). When this temperature contrast is forced to increase, the amplitude of ENSO increases\u2014El Ni\u00f1o becomes warmer and La Ni\u00f1a becomes colder. A stronger La Ni\u00f1a event results in more heat transported to the subsurface of the western Pacific. A stronger El Ni\u00f1o event then warms the eastern Pacific and cools the western Pacific. The effect of a stronger La Ni\u00f1a event does not cancel the effect from a stronger El Ni\u00f1o event. The long-term mean effect of ENSO\u2014the recurrent occurrence of El Ni\u00f1o and La Ni\u00f1a events\u2014is to mix heat downward across the equatorial Pacific and prevent the time-mean difference between Tw and Tc from exceeding a critical value.\r\nThe results have implications for several climatic issues and these implications are discussed. In particular, it is noted that our existing paradigm to understand the response of ENSO to global warming needs to be modified. It is emphasized that it is the tendency in the stability forced by an increase in the greenhouse effect, not the actual changes in the time-mean climate, that ENSO responds to. Changes in the latter\u2014changes in the mean climate\u2014are a residual between the effect of the changes in the radiative forcing and the effect of the changes in the ENSO behavior.","book_title":"Nonlinear Dynamics in Geosciences","series":"","published_year":"2007","published_month":"1","publication":"","publisher":"Springer","pages":"0","place_of_pub":"New York","volume":"","number":"","pagerange":"537-555","doi":"10.1007\/978-0-387-34918-3_29","isbn":"978-0-387-34917-6","official_url":"","pub_type_id":"3","type":"Book_Section","pub_status_id":"3","authors":[{"creator_id":"5755","last_name":"Sun","first_name":"","first_name_abbr":"D.-Z.","orcid":"","pos":"0","branch_id":"21","staff_type_id":"2","short_name":"PSD1","type":"CIRES"}],"editors":[{"id":"5995","last_name":"Elsner","first_name":"","first_name_abbr":" J.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"5996","last_name":"Tsonis","first_name":"","first_name_abbr":"A.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}]},{"id":"19327","title":"The evolving SST record from ICOADS","abstract":"Sea surface temperature (SST) is a key oceanic variable \u2013 widely used for research, including global climate change assessments and atmospheric reanalyses. This paper reviews the evolution of the SST data and products available from the International Comprehensive Ocean-Atmosphere Data Set (ICOADS), since that project\u2019s inception in 1981. Climate-scale SST products based on ICOADS (or related in situ data) are also reviewed. Measurements of SST have been made since around the early 1800s from ships, augmented in recent decades by in situ measurements from buoys and other automated Ocean Data Acquisition Systems (ODAS). SST, unlike some other ICOADS variables such as surface air temperature or humidity, is observed from space with reasonable accuracy. However, without reference to in situ measurements most satellite-based SST products will contain large-scale biases due to varying atmospheric composition and imperfect instrumental calibration. ICOADS is vital to the removal of such biases, which are especially large following volcanic eruptions. We describe products combining in situ and satellite SSTs that exploit the strengths of each type of measurement, to yield both high resolution and high accuracy. Finally, we discuss future developments anticipated for ICOADS and SST products, such as further blending of metadata and enhanced product uncertainty assessments.","book_title":"Climate Variability and Extremes During the Past 100 Years.","series":"","published_year":"2007","published_month":"1","publication":"","publisher":"Springer","pages":"0","place_of_pub":"Berlin","volume":"33","number":"","pagerange":"65-83","doi":"10.1007\/978-1-4020-6766-2_4","isbn":"","official_url":"","pub_type_id":"3","type":"Book_Section","pub_status_id":"3","authors":[{"creator_id":"5514","last_name":"Woodruff","first_name":"","first_name_abbr":"S. D.","orcid":"","pos":"0","branch_id":"23","staff_type_id":"1","short_name":"PSD3","type":"Federal"},{"creator_id":"5515","last_name":"Diaz","first_name":"","first_name_abbr":"H. F.","orcid":"","pos":"1","branch_id":"21","staff_type_id":"1","short_name":"PSD1","type":"Federal"},{"creator_id":"5930","last_name":"Kent","first_name":"","first_name_abbr":"E. C.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5517","last_name":"Reynolds","first_name":"","first_name_abbr":"R. W.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"creator_id":"5516","last_name":"Worley","first_name":"","first_name_abbr":"S. J.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}],"editors":[{"id":"6051","last_name":"Broennimann","first_name":"","first_name_abbr":"S.","orcid":"","pos":"0","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"6052","last_name":"Luterbacher","first_name":"","first_name_abbr":"J.","orcid":"","pos":"1","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"6053","last_name":"Ewen","first_name":"","first_name_abbr":"T.","orcid":"","pos":"2","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"5515","last_name":"Diaz","first_name":"","first_name_abbr":"H. F.","orcid":"","pos":"3","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"6054","last_name":"Stolarski","first_name":"","first_name_abbr":"R. S.","orcid":"","pos":"4","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"},{"id":"6055","last_name":"Neu","first_name":"","first_name_abbr":"U.","orcid":"","pos":"5","branch_id":"1","staff_type_id":"5","short_name":"NONE","type":"other"}]}] }