(National Oceanic and Atmospheric Administration) Derived from the Northern Hemisphere EASE-Grid Weekly Snow Cover and Sea Ice Extent which combines snow cover and sea ice extent at weekly intervals for October 1978 through August 1995, and snow cover only for January 1971 through October 1978. (Sea ice data was not available prior to October 23, 1978.) This data set also includes monthly climatologies describing average extent, probability of occurrence, and variance. The data are provided in a 25 km grid, in an azimuthal, equal area projection (the NSIDC NL EASE-Grid). This dataset has been interpolated to a 1×1 grid.
The snow cover extent is based on the digital NOAA-NESDIS Weekly Northern Hemisphere Snow Charts, revised by D. Robinson (Rutgers University) and regridded to the EASE-Grid. The original NOAA-NESDIS weekly snow charts are derived from the manual interpretation of AVHRR, GOES and other visible-band satellite data. Sea ice extent is based on the NSIDC polar stereographic sea ice concentration grids, derived from Scanning Multi-channel Microwave Radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) passive microwave brightness temperature data. Weekly values are binary where (1/0) indicated coverage or no coverage. Monthly percent of coverage values are calculated from the weekly values for that month and are therefore not integral.
Link to Dataset
NH Ease-Grid Snow Cover
Date last updated: September 1, 1995