Development of a passive microwave global snow monitoring algorithm for the Advanced Microwave Scanning Radiometer-EOS

This paper describes research conducted to develop an integrated snow monitoring algorithm at global and regional scales for the Advanced Microwave Scanning Radiometer - EOS (AMSR-E) due for launch on Aqua in 2001. The AMSR-E will have improved spatial and spectral resolution for snow cover monitoring compared with the currently available Special Sensor Microwave Imager (SSM/I) instrument. Two algorithm calibration elements are proposed which epitomise the calibration effort. The first, which is described, is the production of a monthly geographically distributed SWE coefficient is produced that reflects long-term average monthly characteristics of SWE. The second element, which is still under development and is not described, is to encompass local variability in SWE determined by geographic variations in snowpack physical characteristics. Simulated AMSR-E PM observations (derived from SSM/I data) of land surfaces and ancillary data (forest fraction) are combined through emipirical statistical and geostatistical models to produce global monthly coefficients that are used to estimate SWE from a physically-based model