Soil Moisture Retrieved from Microwave Satellite Data and Its Relationship with the Asian Dust (Hwangsa) Frequency in East Asia during the Period from 2003 to 2010

摘要

A soil moisture retrieval algorithm using AMSR-E microwave satellite data has been developed by the National Institute of Meteorological Research (NIMR). This algorithm is based on a simple inversion method that does not require a prior soil texture data. In this study, the relationship between soil moisture retrieved from the NIMR algorithm and the occurrence of Asian dust (Hwangsa) is statistically analyzed. The frequency of occurrence of Asian dust events was recorded at 410 sites in China from 2003-2010 in three regions; the Gobi desert, Inner Mongolia and Northeast China. Results showed low soil moisture values of around 0.1 g cm~(-3) in the Gobi desert and Inner Mongolia-lowest in summer and a little higher in winter. Soil moisture values in Northeast China were marginally higher than in other regions, but lowest in winter and higher in summer. About 55% of Asian dust in the Gobi desert occurred when the monthly mean soil moisture was less than the monthly mean soil moisture for eight years. Approximately 75% of Asian dust in Northeast China occurred when soil moisture was the same as the monthly mean soil moisture for eight years. While soil moisture in the Gobi desert and Inner Mongolia declined in spring, it increased in Northeast of China.