Temporal Coverage: 24 February 2000 - present (Terra); 3 July 2002 - present (Aqua)
The MODIS Normalized Difference Snow Index (NDSI) snow cover layer shows the presence of snow cover over land and water bodies as an index related to the presence of snow. NDSI snow cover is derived from the cloud free snow reflectance sensed by the MODIS instrument, and hence this layer shows presence of snow during day time and under cloud clear condition only. NDSI snow cover though could be retrieved in the valid range of (0, 1.0) at every pixel, additional tests like surface temperature screening linked with the surface height is used for accurate detection. Snow is precipitation that forms from water vapor in the atmosphere where temperatures are below 0° Celsius. If the ground temperature is also below freezing, snow will accumulate on the ground as bright, white layer of snowpack. Snow cover reflects sunlight back into the atmosphere, helping to cool the Earth’s surface. Snowmelt is used for drinking water, water for crop irrigation, and can moisturize soil to reduce the risk of wildfire in many areas in the world. When snow melts in the spring, too much snow can cause springtime flooding.
The MODIS Snow Cover (Normalized Difference Snow Index) layer is available from both the Terra (MOD10) and Aqua (MYD10) satellites. The sensor and imagery resolution is 500 m and the temporal resolution is daily.
References: NSIDC - MYD10L2; NSIDC - MOD10L2; NASA Earth Observations - Snow Cover
Temporal coverage: 24 February 2000 - present (Terra); July 2002 - present (Aqua)
Temporal coverage: March 2000 - present (Terra); July 2002 - present (Aqua)