塔里木盆地沙尘天气日数的变化及其与北大西洋涛动的联系

Variation of Dust Storm Days in Tarim Basin and Its Relation with North Atlantic Oscillation

基于塔里木盆地35站1961—2007年的沙尘暴、扬沙日数的观测资料,分析了塔里木盆地春、夏季沙尘天气日数的时空变化特征及其变化的可能原因。结果表明,沙尘暴和扬沙日数呈显著减少趋势,沙尘暴日数在盆地的西南部,扬沙日数在盆地的东北部,减少幅度最大。春、夏季沙尘暴日数的气候突变发生在20世纪80年代的中后期,而扬沙日数在90年代的中后期。春、夏季沙尘天气日数以单月发生为主,连续2月及以上发生概率较大的区域集中在天山南坡,尤其在阿克苏地区。近20a来,沙尘天气日数异常站数迅速减少,尤其在2000年后。相关分析表明,前冬北大西洋涛动指数与春、夏季沙尘暴日数有较好的相关关系,可以作为其短期气候预测的一个因子。

The spatial and temporal variation characteristics of sandstorm and blowing sand days in spring and summer in the Tarim Basin and its reason were analyzed based on observation data of sandstorm and blowing sand days at 35 stations during 1961—2007.The sandstorm and blowing sand days presented obviously descending trend,and the sandstorm and blowing sand days had the maximum descending range in southwest and northeast basin,respectively.The abrupt change of sandstorm days in spring and summer happened in middle-late 1980s,but the abrupt change of the blowing sand days occurred in middle-late 1990s in Tarim Basin.Most of the sand-dust weather lasted for one month,and that lasted for two months or more mainly occurred in northern parts of the Tarim Basin,especially in Aksu area.In the recent 20 years,the number of the stations recorded sand-dust days anomaly decreased rapidly,especially after 2000.The correlation analysis showed that the North Atlantic Oscillation index in previous winter had good correlation with sandstorm and blowing sand days in spring and summer in the Tarim Basin,and it could be used as a predictive factor for dust storm days in the study region.