ICOADS Data Online at the NOAA Earth System Research Laboratory

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. Please refer to the ICOADS Website for more information about the ICOADS project, observational and summary products, and associated metadata.

The Physical Science Division (PSD) of NOAA's Earth System Research Laboratory (ESRL) provides online access to the ICOADS monthly summary statistics for 2° latitude x 2° longitude boxes (and for 1°x1° boxes starting in 1960). These online data are distributed in the netCDF format using metadata conventions developed at PSD. Among the conventions are the attributes scale_factor and add_offset, which are used to pack floating-point data into 16-bit integers (additional technical details). The netCDF files can be downloaded by anonymous FTP or by following hyperlinks below. PSD can supply Fortran code and can suggest other software that can be used to display and analyze the ICOADS data.

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).

For data starting in 1960, the netCDF files are further subdivided by gridbox size (2°x2° or 1°x1° boxes) and spatial domain, with the 1°x1° summaries available in global and equatorial formats. The equatorial products cover the latitude band 10.5°N to 10.5°S, and are global with respect to longitude. In contrast to the global 1°x1° boxes, the equatorial 1°x1°boxes are shifted half a degree in latitude (only) in comparison to the global domain, such that the center-latitude of the central row of boxes is the equator (e.g., 0-1°E, 0.5°S-0.5°N). Both the global and equatorial formats have a standard and enhanced product.

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

The following pages provide access to the data by box size, and selections within these pages provide access to the further subdivisions of data by spatial domain and product type (as applicable):

• ICOADS 2°x2° products (1800-Dec 2014; Release 3.0) extended by preliminary summaries updated monthly to near-real-time
• ICOADS 1°x1° products (1960-Dec 2014; Release 3.0) extended by preliminary summaries updated monthly to near-real-time
• ICOADS 2°x2° long-term monthly mean products (1981-2010 based on Release 3.0 enhanced (1981-2010); 1971-2000 based on Release 2.5 enhanced summaries; and 1950-79 based on original COADS Release 1 summaries)

1. Release 3.0 1662 through 2014
2. Following the Release 3.0 end date, data are based on a blend of NCEI real-time GTS BUFR and TAC data with minimal quality control. These data should be considered preliminary and will be subject to change in new releases.