GHRSST Reanalysis/GCOS SST-SI Intercomparison Data Sets

All GCOS data sets are available in Matlab (V7.3) and netCDF formats. The netCDF files are COARDS/CF compliant and conform to the GHRSST format and content conventions. Please note the file names follow the proposed GHRSST Data Specification 2.0 filename convention. Note also that unlike other GHRSST files, these intercomparison data sets contain 3-dimensional cubes of data, not just a single swath or grid in time. You can click on the netCDF or Matlab links in the tables, or navigate to the following locations to access all of the data sets:

• FTP: ftp://data.nodc.noaa.gov/pub/data.nodc/GCOS
• HTTP: http://data.nodc.noaa.gov/GCOS
• OPeNDAP: Coming soon!

Satellite Era Data Sets

The initial set of intercomparison products is listed below in two tables, one for the weekly and one for the monthly data. These data span only the time period in which modern satellite-based records are available, or roughly 1981 to the present. Click on the links in the tables to access more information about each product, the complete data sets, their climatologies, and the Matlab software used to reformat the data for this project.

Historical Data Sets

The set of historical intercomparison products is listed in the table below. These are primarily in situ-based data that span the majority of the time period in which sea surface temperature observations have been collected, or roughly 1850 to the present. Click on the links in the tables to access more information about each product, the complete data sets, their climatologies, and the Matlab software used to reformat the data for this project.

*Please note that the Matlab scripts available on this website are designed to illustrate the processing steps taken for each data set. They were written to cater to specific pathways on the author's computer, and are by no means complete. They will not function independently to load or parse GCOS data sets. Please direct any questions about processing or reading this data to Tess Brandon at tess.brandon@noaa.gov.

About Processing of GCOS Data Sets

The SST products used in this project were gathered from a variety of sources, and originally existed in a variety of formats. The primary task was therefore to reprocess all of these products to a standard format. Each GCOS data set contains four gridded three-dimensional variables: sea surface temperature, analysed error/standard deviation of sea surface temperature, percentage of sea ice cover, and a composite sea/land/lake/ice mask. Variables that are not available for a given data set are populated with missing values. The three dimensions that define these variables are time, latitude and longitude.

Weekly one degree data sets are on a grid with pixel centers located at latitudes from -89.5 degrees to 89.5 degrees and longitudes from -179.5 degrees to 179.5 degrees. All data sets are forced onto the same time series, which runs from week 44 (November) of 1981 through the last week of 2007, resulting in 1366 weeks. For some products this excludes historical data that is not considered useful for the intercomparison efforts of this project. Weeks that are not available for a given product are populated with missing values. All weekly data sets were created from either weekly or daily files, and averaged in time according to the center day of each week as defined by the SST-Sea Ice Intercomparion Week Centers. For daily products, three days before and after this center day were averaged to create standard weekly averages.

Monthly five degree data sets are on a grid with pixel centers located at latitudes from -87.5 degrees to 87.5 degrees and longitudes from -177.5 degrees to 177.5 degrees. All data sets are forced onto the same time series, which for the satellite era runs from January of 1981 through December of 2007, resulting in 324 months. Historical data sets are forced onto a time series that runs from January of 1850 through June of 2008, resulting in 1902 months. Months that are not available for a given product are populated with missing values. All monthly data sets for the satellite era were created from either daily or monthly files, and represent calendar months (see our Calendar Date Conversion Chart). Center days for each month in the satellite era are defined in the file times_monthly.txt. All historical monthly data sets were created from monthly files. The unit of time used for all of these files, "months since January of 1850", can be found in the file times_monthly_retro.txt.

For ease of comparison among the data sets, a GCOS binary land mask was created at both one degree and five degree resolution from the National Geophysical Data Center's Global Gridded 2-minute Bathymetry product. Click on the Matlab or netCDF links in the table below to download these land masks: