干旱区生态环境知识资源中心

This study presents dust event spatiotemporal distribution and regional trends, and the impact of surface wind and precipitation on dust occurrences in Mongolia. We used data collected between 2000 and 2013 from 113 meteorological stations in natural forest steppe, steppe, Gobi Desert, and mountain zones. We analyzed the relationship between dusty days, derived using the sum of days with dust storms and/or drifting dust, and days with strong winds (at a threshold wind speed of a constant 6.5 m s(-1), hereafter, strong wind days) and precipitation by comparing the dusty days in dust-frequent years, dust-less years, and dust-mean years. Dusty days in dust-frequent years were associated with strong wind days when the precipitation is about 10 mm and dust occurrences were suppressed by large amounts of precipitation (approximately 22 mm) in dust-less years over the southeastern part of the Gobi Desert in May. We propose a potential dust index (PDI) based on the correlations among dusty days, strong winds and precipitation. The PDI performed as predicted in most areas of the country in the spring season.