塔里木盆地春季沙尘暴频次与大气环流的关系

使用1961-2009年春季NCEP/NCAR再分析资料和塔里木盆地37个气象站沙尘暴频次资料,分析了塔里木盆地春季沙尘暴频次与大气环流的关系。结果表明:①近40 a,在500 hPa高度场上,两者在巴黎盆地和蒙古国中西部存在显著负相关,在乌拉尔河附近存在正相关,蒙古国中西部500 hPa高度场在升高,而乌拉尔地区的在降低,两地间经向环流的减小引起盆地沙尘暴减少。②塔里木盆地春季沙尘暴频次突变与显著负相关区蒙古国西部500 hPa高度场突变相联系,两者的变化趋势基本是相反的,盆地沙尘暴频次突变出现在1985年,500 hPa位势高度突变提前于沙尘暴频次突变,出现在1980年和1984年。③在年际、年代际尺度上,春季500 hPa位势高度场上蒙古国西部气旋和东欧平原反气旋增强的环流形势配置是塔里木盆地沙尘暴多值年的典型背景。

Relationship between Spring Sandstorm Frequency in the Tarim Basin and Atmospheric Circulation

The relationship between spring sandstorm frequency in the Tarim Basin and atmospheric circulation is analyzed based on the NCEP/NCAR reanalysis data during 1961-2009 and the monthly sandstorm frequency data from 37 weather stations in Tarim Basin.Results show that their relationship is close.There is significantly negative relationship between spring sandstorm frequency in the Tarim Basin and the atmospheric circulation at 500 hPa geopotential height in the Paris Basin and the middle-west Mongolia;there is positive relationship with atmospheric circulation in the Ural River.The 500 hPa geopotential height increased in the middle-west Mongolia in recent 50 years,decreased in the Ural River;the decrease of longitude circulation between these two areas caused the decrease of sandstorm frequency in the Tarim Basin.The abrupt change of spring sandstorm frequency in the Tarim Basin is associated with the abrupt change of 500 hPa geopotential height in the west of Mongolia,and their variation trend is almost opposite.The abrupt change of sandstorm frequency happened in 1985,but that of the 500 hPa geopotential height happened in 1980 and 1984.The enhancement of 500 hPa geopotential height cyclone in the west Mongolia and anticyclone in the East Europe Plain is the typical circulation situation of frequent sandstorm events in spring in the Tarim Basin.