Spatial and temporal series analysis of snow cover extent and snow water equivalent for satellite passive microwave data in the northern hemisphere (1978–2010)

Snow water equivalent (SWE) is a critical parameter for climatological and hydrological studies over northern high-latitude areas. Based on the long time observation and monitoring of SWE, we can discover the climate changes tendency. Most conventional SWE retrieval algorithms, well known as NASA algorithms, depend on the difference between brightness temperatures near 19 (or 18) and 37 GHz. Until now, there are as many as 6 PMRs' data to derive hemisphere-scale snowpack since 1978. In this paper, we collected the microwave radiometry's SWE products in the Equal-Area Scalable Earth Grid (EASE-GRID) to do time series analysis in the northern hemisphere during the period 1978–2010, including the Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor Microwave Imager (SSM/I) and The Advanced Microwave Scanning Radiometer-EOS (AMSRE). After adjusting the systematical difference of these three snow products in winter, the snow cover extent and SWE changes for 1978–2010 are available. We found in the past 33 years, both SWE/snow mass and snow cover decreased. Besides, in order to gain the information of spatial variations of snow cover extent and SWE in the northern hemisphere, several interesting area such as China, North America, Eurasia, Siberia, and Arctic Circle are illustrated.