TIME SERIES of SEASONALLY FROZEN GROUND DEPTH in the RUSSIAN ARCTIC, 1930-1990 DATA ORGANIZATION Data files are named following the convention TMD2.sss.max where sss is the three-digit station identification number. These files provide yearly average freeze depths in meters. The supplementary composite file including the seasonally frozen ground depth of all 211 sites for each year is titled Composite_1930-1990_SFG.txt. The following files are also included in the directory: sf_station_locations.gif - This GIF file shows the distribution of the 211 ground-based stations where data was collected. Freeze_Depth-Station_List.xls - This Excel file includes a list of the 211 ground-based stations with their station ID, region ID, World Meteorological Organization ID, station name, latitude, longitude, and elevation (m). DOCUMENTATION We recommend that you read the complete documentation in detail before working with the data.