准噶尔盆地南缘“2008.04.17”沙尘暴天气成因分析

利用常规观测资料、地面气象自动站资料和数值预报产品T213资料,对2008年4月17日下午准噶尔盆地南缘石河子垦区出现的沙尘暴天气过程的成因进行了分析。结果表明:西西伯利亚冷槽的斜压性结构使其强烈发展,为沙尘暴的发生提供了动力条件。而西西伯利亚冷槽的垂直结构强迫出一支下沉气流,为沙尘暴的发生提供了动量下传机制。沙尘暴是高空急流及高空锋区,在中、高纬地区共同作用的结果。沙尘暴爆发过程中,动力场、热力场的交换非常明显。沙尘暴发生在地面冷锋后部、冷高压前部、3h变压、变温最大处和气流辐散的地区。

Analysis of a sandstorm weather case in April 17,2008 in the south of Junggar Basin

Using data of basic observation,automatic meteorological ground stations and numerical forecasting product T213,we analyzed the causes of a sandstorm weather process in April 17,2008 pm.in Shihezi city of Junggar Basin.This weather process was formed under the West Siberian Cold Trough moving towards southeast and developing greatly.The involvement of very cold air made the West Siberian Cold Trough developed further,which provided the forcing condition for sandstorm.The vertical structure of Siberian Cold Trough provided the mechanism of momentum transmitting downwards for sandstorm.High-altitude jet and High-altitude front zone concurred to produce Sandstorm in the medium and high-latitude regions.And there also was an exchange of Dynamic and Thermal Fields.The Strong sandstorm occurred under the conditions of the rear of cold front,the front of cold high pressure,changes in air pressure for 3h,the region of the greatest change in temperature and the airflow divergence.