吐鲁番地区一次强沙尘暴天气分析

Analysis of a Strong Sandstorm in Tur pan Area

对2001年4月7～8日发生在吐鲁番地区的强沙尘暴天气进行了天气成因分析。分析表明,此次天气是由乌拉尔山南下的强冷空气沿偏北路径引发的。前期持续增温和槽前暖平流为沙尘暴天气的发生提供了有利的热力条件;高空槽前强烈的正涡度平流为沙尘暴天气提供了动力条件;干暖舌的形成和维持对沙尘暴天气的发生、强弱及持续有较好的指示性;高空急流的振荡合并导致对流层中、下层锋区加强和大气层结不稳定,为沙尘暴天气的产生提供了有利的大尺度环流背景;吐鲁番盆地特殊的地形,为沙尘暴天气的形成和加强起到了推波助澜的作用;盆地土质疏松、含沙量大、植被稀少的地表则为沙尘暴天气的形成提供了有利的地理环境。

A strong sandstorm weather process o ccurred from 7th to 8th on April 2001i n Turpan area .The analysis shows that the event was caused by the leaning north stron g cold from the south of the Ural mount ain.Temperature rising and warm air current were the fa-vorable thermal condition to lead to the strong sandstorm.The developme nt and persistence of dry warmer sector was the index of its occurrence.The oscillation and com bination of upper air jet intensifie d the front in the middle and low troposphere and the unsteady at-mospheric levels which provided a fa vorable large -scale circulation background.The special topography in Turpan's basin played an important role to form and strengthen the sandstorm.The ground surface which has the loosen loam,a lot of sand and rare plants were provided a favorable condition geographically.