High-Resolution Image

Spatially complete white-sky albedo at 0.86 µm from January 1-16, 2002 without (top) and with (bottom) overlaid snow albedo values. Snow albedo values are based on the MODIS-derived hemispherical snow albedo as a function of IGBP ecosystem classification. The location of the snow on the Earth's surface is derived from the National Snow and Ice Data Center (NSIDC) near-real time ice and snow extent (NISE) dataset that is available daily at 25 km resolution which itself is based on satellite-borne microwave radiometers.

The snow albedo statistics are used in tandem with the snow-free spatially complete surface albedo map to provide dynamically tailored surface albedo maps that are a necessary boundary condition in the estimation of cloud optical thickness and effective radius from reflected solar radiation measurements on MODIS. This algorithm starts with a base 16-day discrete wavelength snow-free spatially complete surface albedo map, defines where the snow is present (via NISE) and the underlying IGBP ecosystem class, and then overlays snow albedo values using the lookup table of snow albedo statistics.

(Submitted by Eric Moody and Michael King)