MODIS/Terra Snow Cover 8-Day L3 Global 500m Grid (MOD10A2) contains data fields for maximum snow cover extent over an 8-day compositing period and a chronology of snow occurrence observations in HDF-EOS format, along with corresponding metadata. MOD10A2 consists of 1200 km by 1200 km tiles of 500 m resolution data gridded in a sinusoidal map projection. MODIS/Terra V004 data extend from 24 ... February 2000 to present. MODIS snow cover data are based on a snow mapping algorithm that employs a Normalized Difference Snow Index (NDSI) and other criteria tests. The only data available for Version 4 (V004) is the Golden Month, which is a sample of V004 data covering the time period 29 August 2002 (day of year 241) through 7 October 2002 (day of year 280). The Golden Month is only available by special request by contacting NSIDC User Services. Please note that NSIDC now has a complete series of Version 5 data, which is the highest version number now available and represents the best quality of data.