塔城3.12东风沙尘暴天气模拟分析

新疆塔城向来以水草丰美著称于世，但2005年底和2006年初却连续发生3场大的沙尘暴，引起恐慌。本文采用mm5v3模式做气象场实验，hysplit4.7轨迹模式做扩散与沙尘来源分析。利用卫星遥感图做对比。分析了3?12东风沙尘暴天气。研究表明：500hPa图上乌拉尔山脊向东北发展，在新疆北疆形成一个东西向的横槽，北疆北部为一致的东风，受其引导，北疆地面形成大范围的东风，经过塔城老风口，在塔城地区形成强的下坡风。加之当时该区域积雪过早融化耕地裸露，大风卷起土壤形成这次沙尘暴。mm5v3模式模式较好的模拟了强的东风下坡风；经过与遥感对比，hysplit4.7轨迹模式较好的模拟了起沙沙源地和扩散过程。

Simulation of Tacheng 3.12 East-wind Sandstorm

Tacheng has always been famous for its lush plants. However, the occurrences of three heavy sandstorms there since the end of 2005 till the beginning of 2006 has caused great panic. To learn them in depth, this paper conducts a meteorological experiment by mm5v3 and then analyzed their divergence and source by the trace model hysplit4.7, while the whole weather process was studied through comparing different satellite remote sensing images. It is showed that, the Urals ridge over 500hPa developed toward northeast and formed a east-west trough over northern Xinjiang. Derived by the east wind on north part of northern Xinjiang over this level, a large-range band of east wind formed on the ground layer here. This eastward stream passed the wind-gap in Tacheng and caused strong downslope wind, which caused this heavy sandstorm while blowing over the bare agricultural field where the snow melted earlier than average. The eastward downhill wind has been well simulated by mm5v3, the source area and diffusion process of the sand has been successfully simulated by hysplit4.7 while compared with the remote sensing dataset.