The Environmental Working Group Joint U.S.-Russian Arctic Sea Ice Atlas is part of the NOAA@NSIDC Environmental Working Group (EWG) Atlases data collection. The EWG Joint U.S.-Russian Arctic Sea Ice Atlas was developed by U.S. and Russian partners in the late 1990s. It is based on observations collected over the period 1950 through 1994 from satellite data, ice stations, icebreakers, and airborne ice surveys. Additionally, U.S. submarines operating in the Arctic over the period from 1977 through 1993 collected data used for a previously classified ice climatology. The Atlas contains four main sections: an introduction to Arctic sea ice, a section that describes primary sea ice data sets and analysis methods, a section with a graphical atlas containing two-dimensional color-coded ice charts and graphical products, and an Arctic sea ice data section. Note: The Russian chart component of this product has been replaced and updated by Sea Ice Charts of the Russian Arctic in Gridded Format, 1933-2006 and the U.S chart component by National Ice Center Arctic Sea Ice Charts and Climatologies in Gridded Format, 1972-2007 and U.S. National Ice Center Arctic and Antarctic Sea Ice Concentration and Climatologies in Gridded Format.