银川河东机场沙尘天气环流类型及动力结构研究

Study on the circulation type and dynamic structure of dust weather over Yinchuan Hedong airport

选取1998-2010年银川河东机场29次沙尘暴天气典型个例,采用天气学和统计分析方法研究了河东机场沙尘暴天气的环流类型及其动力机制。结果表明:银川河东机场沙尘暴天气的环流类型分为4类,即:新疆冷槽型、小槽发展型、强西北气流型、东高西低型,其中新疆冷槽型沙尘暴天气是河东机场最主要的沙尘暴环流类型;强沙尘暴天气发生时一般都伴随着高空急流加强;而沙尘暴天气爆发时散度场的分布为低层辐合高层辐散。

In this research some typical dust storms from 1998 to 2010 over Yinchuan A irporl were selected, and the circulation types and dynamic structure of dust weather were studied by the synoptic analysis methods. The results showed that the circulation type of dust weather over Yinchuan Hedong airport are divided into four types, namely, Xinxiang cold trough pattern, development of small type trough pattern, strong northwest airflow pal- tern, and high east and low west pattern. The main type of dust cirulation over Yinchuan Airport is Xiujiang cold trough pattern. When strong sandstorms oecuring, there are generally associated with upper-level jet existing and strengthening. When the upperlevel westerly jet and the subtropical jet oscillating and c.omplicating, frontal zone in the middle and lower troposphere（500hPa and 700hPa） will be strengthened significantly, and lead lo instability of atmospheric stratifcation and development of middle - lower pressure. When sandstorm breaking out,generally,low- level atmosphere for convergence zone, upperlevel for divergence zone, the atmospheric＇ structure is beneficial to maintaining ascending motion and making diffusion and suspension of dust in the air by the surface strong wind.