AMIP with Observed Radiative Forcing, Climatological Sea Ice and Polar SST

Description: AMIP conditions in which sea ice is set to a repeating seasonal cycle of 1979-1989 (pre-emergnce of the melt out). SST is defined as described below.

Experiment ID: amip_clim_polar

Years: 1979-2012

Forcings

Sea Surface Temperature (SST)

The SST in the polar regions are specified as follows:

  • For the grid points where the 1979-89 climatological sea-ice coverage of a month (e.g. January) is 100%, SST = -1.8 C
  • For the grid points where the 1979-89 climatological sea-ice coverage of a month is greater than 0, but less than 100%, SST is specified to the value of 1979-89 climatology of the respective month.
  • For the grid points where the 1979-89 climatological sea-ice coverage of a month is 0, SST is specified as observed monthly value of that particular year-month (e.g. January of 2013).

SST values are from the dataset described here:

Hurrell, James W., James J. Hack, Dennis Shea, Julie M. Caron, James Rosinski, 2008: A New Sea Surface Temperature and Sea Ice Boundary Dataset for the Community Atmosphere Model. J. Climate, 21, 5145–5153. doi: 0.1175/2008JCLI2292.1

Forcing file: SST & Sea Ice
Sea Ice (SIC) A repeating seasonal cycle of roughly 1979-1989 (pre-emergnce of the melt out). Values are from the dataset described here:

Hurrell, James W., James J. Hack, Dennis Shea, Julie M. Caron, James Rosinski, 2008: A New Sea Surface Temperature and Sea Ice Boundary Dataset for the Community Atmosphere Model. J. Climate, 21, 5145–5153. doi: 0.1175/2008JCLI2292.1

Forcing file: SST & Sea Ice
Greenhouse Gases (GHG) Values from:

Meinshausen, M., S. J. Smith, K. V. Calvin, J. S. Daniel, M. Kainuma, J.-F. Lamarque, K. Matsumoto, S. A. Montzka, S. C. B. Raper, K. Riahi, A. M. Thomson, G. J. M. Velders and D. van Vuuren (2011). The RCP Greenhouse Gas Concentrations and their Extension from 1765 to 2300. Climatic Change (Special Issue). doi: 10.1007/s10584-011-0156-z

which are the CMIP5 Recommendations for annual average, global mean concentrations.
Ozone (03) ECHAM5: Values from the AC&C/SPARC ozone database:

Cionni, I., V. Eyring, J. F. Lamarque, W. J. Randel, D. S. Stevenson, F. Wu, G. E. Bodeker, T. G. Shepherd, D. T. Shindell, and D. W. Waugh, 2011: Ozone database in support of CMIP5 simulations: results and corresponding radiative forcing, Atmos. Chem. Phys. Discuss., 11, 10875-10933, doi: 10.5194/acpd-11-10875-2011 , 2011.

CAM4: values from:

Lamarque, J.-F., Emmons, L. K., Hess, P. G., Kinnison, D. E., Tilmes, S., Vitt, F., Heald, C. L., Holland, E. A., Lauritzen, P. H., Neu, J., Orlando, J. J., Rasch, P. J., and Tyndall, G. K., 2012: '''CAM- chem: description and evaluation of interactive atmospheric chemistry in the Community Earth System Model''', Geosci. Model Dev., 5, 369–411,doi: 10.5194/gmd-5-369-2012, 2012.

Aerosols ECHAM5 uses a built-in, time independent aerosol model which is based on atmosphere layers, and land and water surface types, described here:

Tanre, D., Geleyn, J.-F. and Slingo, J. M. (1984): First results of the introduction of an advanced aerosol-radiation interaction in the ecmwf low resolution global model. In: Aerosols and Their Climatic Effects, edited by Gerber, H. and Deepak, A., pp. 133–177. A. Deepak, Hampton, Va.

CAM4 uses time-varying aerosol content, and volcano aerosols from 1979-2005. After 2005, RCP6 aerosols (with no volcanoes) are used.