ICOADS R2.5 2 Degree

One-Line Description:

• The International Comprehensive Ocean-Atmosphere Data Set (ICOADS) is the most extensive collection of surface marine data spanning the past three centuries, together with simple gridded monthly summary products extending from 1800 forward.

Temporal Coverage:

• Monthly values for 1800/01 - 2007/12.
• Preliminary monthly values for 2008/01 - present.

  IMPORTANT: The time period of these products is defined in two segments.

  1. Release 2.5 1800 through 2007
  2. Following the Release 2.5 end date data are based exclusively on real-time GTS data with minimal quality control. These data should be considered preliminary and will be subject to change in new releases.

Spatial Coverage:

• 2.0 degree latitude x 2.0 degree longitude global grid (90x180).
• 89.0N - 89.0S, 1.0E - 359.0E.

Levels:

• Sea Surface

Update Schedule:

• Irregular (dependent on project resources and data availability considerations)
• Monthly (preliminary segment)

Download/Plot Data: (FTP Access)

Variable	Statistic	Level	Download File	Create Plot/Subset
Sea Surface Temperature (S)	Multiple	Surface	sst.*.nc
Air Temperature (A)	Multiple	Surface	air.*.nc
Scalar Wind (W)	Multiple	Surface	wspd.*.nc
U-wind (U)	Multiple	Surface	uwnd.*.nc
V-wind (V)	Multiple	Surface	vwnd.*.nc
Sea Level Pressure (P)	Multiple	Surface	slp.*.nc
Cloudiness (C)	Multiple	Surface	cldc.*.nc
Specific Humidity (Q)	Multiple	Surface	shum.*.nc
Relative Humidity (R)	Multiple	Surface	rhum.*.nc
Sea-air Temperature difference (S-A)	Multiple	Surface	smina.*.nc
Sensible Heat Parameter ([S-A]*W)	Multiple	Surface	sflx.*.nc
Sat Sp Hum at SST minus Sp Hum (Qs-Q)	Multiple	Surface	qsminq.*.nc
Latent Heat Parameter ([Qs-Q]*W)	Multiple	Surface	lflx.*.nc
U-wind Stress (U*W)	Multiple	Surface	upstr.*.nc
V-wind Stress (V*W)	Multiple	Surface	vpstr.*.nc
Sensible Heat Trans Eastward Param (U*A)	Multiple	Surface	uairt.*.nc
Sensible Heat Trans Northward Param (V*A)	Multiple	Surface	vairt.*.nc
Latent Heat Trans Eastward Param (U*Q)	Multiple	Surface	uspeh.*.nc
Latent Heat Trans Northward Param (V*Q)	Multiple	Surface	vspeh.*.nc
Zonal Latent Heat Parameter (U*[Qs-Q])	Multiple	Surface	ulflx.*.nc
Meridional Latent Heat Parameter (V*[Qs-Q])	Multiple	Surface	vlflx.*.nc
Scalar Wind cubed (W*W*W)	Multiple	Surface	wspd3.*.nc

Variable	Statistic	Level	Download File	Create Plot/Subset
Multiple	First Sextile	Surface	*.sextile1.nc
Multiple	Third Sextile (Median)	Surface	*.sextile3.nc
Multiple	Fifth Sextile	Surface	*.sextile5.nc
Multiple	Mean	Surface	*.mean.nc
Multiple	Number of Observations	Surface	*.nobs.nc
Multiple	Standard Deviation	Surface	*.stddev.nc
Multiple	Mean Day of Month of Observations	Surface	*.mean_day.nc
Multiple	Fraction of Observations in Daylight	Surface	*.day_fraction.nc
Multiple	Mean Longitude (Off SW Corner of Box) of Observations	Surface	*.mean_lon.nc
Multiple	Mean Latitude (Off SW Corner of Box) of Observations	Surface	*.mean_lat.nc

Usage Restrictions:

• None

Detailed Description:

• The netCDF files are subdivided into "standard" and "enhanced" products, which reflect the "trimming" (quality control) procedure used and the data mixture. In the standard products, the data have been edited using climatological 3.5 standard-deviation (sigma) limits, with the observations limited (as nearly as practical) to those from ships. In the "enhanced" products, in contrast, the data have been edited using broader 4.5 sigma limits to better represent extreme climate events, with observations from ships plus from other in situ marine platform types (e.g., drifting and moored buoys).
  
  Please refer to the ICOADS Website for more information about the ICOADS project, observational and summary products, and associated metadata.

Caveats:

• Small numerical biases in previous netCDF files are described here.

Related File Naming & Structure Information:

File Names:

• var.stat.nc   (In directory: /Datasets/icoads2.5/2degree/)

Dataset Format and Size:

• PSL standard NetCDF >80 Mbyte file for each global file (packed).
• PSL standard NetCDF >161 Mbyte file for each global wspd3 file.

Missing Data:

• Missing data is flagged with a value of 32766s.
• Missing data is flagged with a value of -9.96921e+36f.

Citation:

• Please note: If you acquire ICOADS2.5 data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as ICOADS2.5 data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the ICOADS2.5 data set freely available online in the future. Thank you!

References:

• Please refer to the ICOADS Website Publications page.

Original Source:

• Multinational. The US contribution is the result of a cooperative project between the National Oceanic and Atmospheric Administration (NOAA)--specifically its Earth System Research Laboratories (ESRL), its National Climatic Data Center (NCDC), and the Cooperative Institute for Research in Environmental Sciences (CIRES), conducted jointly with the University of Colorado--and the National Science Foundation's National Center for Atmospheric Research (NCAR).

Contact:

• NetCDF questions:
  
  Physical Sciences Laboratory: Data Management
  NOAA/ESRL/PSL
  325 Broadway
  Boulder, CO 80305-3328
  psl.data@noaa.gov
  
• Data questions:
  
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