The Environmental Working Group Joint U.S.-Russian Atlas of the Arctic Ocean is part of the NOAA@NSIDC Environmental Working Group (EWG) Atlases data collection. The Environmental Working Group (EWG) was established in 1995 under the framework of the U.S.-Russian Joint Commission on Economic and Technological Cooperation. The EWG Arctic Climatology Group took on the task of compiling digital data on arctic regions. This atlas of the Arctic Ocean was developed by specialists from the Environmental Research Institute of Michigan with Russian and U.S. partners. Separate volumes for winter and summer have file names G01961a and G01961b respectively. More than 1.3 million individual temperature and salinity observations collected from Russian and western drifting stations, ice breakers, and airborne expeditions were used to develop the products contained in the winter volume. The primary products of the Atlas are gridded mean fields for decadal periods (1950s,1960s, 1970s, 1980s) of temperature, salinity, density and dynamic height, Atlantic water layer depth, and temperature and salinity profiles and transects. The original individual observations that were used to derive these fields are not provided with the Atlas and are not available. Note that the Polar Science Center Hydrographic Climatology (PHC) ocean database (version 3.0) is available from the Polar Science Center, Applied Physics Laboratory, University of Washington. This is a global gridded database with a high-quality description of arctic seas achieved by merging data from several sources, including data from the Environmental Working Group Joint U.S.-Russian Atlas of the Arctic Ocean. The PHC or later versions may be more suitable for your research. As of January 2023, contact Michael Steele, Applied Physics Laboratory, 1013 NE 40th Street, Seattle, WA 98105 if you are interested in learning more about the PHC.