Estimate of fractional snow cover using MODIS data

Information from the Moderate Resolution Imaging Spectroradiometer (MODIS), launched on the Terra satellite in December 1999, is considered a powerful means to improve global snow cover maps and to generate a fractional snow cover product. Estimates of snow fraction are viewed as useful for atmospheric and hydrologic snowmelt runoff modeling, monitoring changes in snow coverage and energy fluxes, as well as for several other applications. Within the framework of the current study the performance of different potential approaches to snow fraction retrieval has been assessed. Statistical relationships were developed between the normalized difference snow index (NDSI) from MODIS observations and the fraction of snow-cover at 500-meter grid resolution. The accuracy of the snow fraction regression with NDSI meets or exceeds the quality of other assessed methods. It confirmed that using of NDSI for fractional snow retrieval is very promising. Plans include further development and improvement of fractional snow retrieval for MODIS cell size (500/spl times/500 m).