石嘴山市2020年2次大雾过程对比分析

Comparative Analysis of Two Heavy Fog Processes in Shizuishan City in 2020

利用常规气象观测资料对2020年9月10日和14日石嘴山市2次大雾天气过程的环流背景、影响系统及大雾过程前后的大气层结特征、气象要素场、物理条件等进行综合分析,结果表明:2次大雾天气是由高空浅脊、低压槽、冷平流等天气系统作用影响形成的。其中,500 hPa中纬度西风气流、850 hPa弱偏南气流、地面位于减弱冷高压后部为大雾天气的形成提供了有利的环境场,伴有晴空辐射,是典型的辐射雾。前期降雨使近地面层湿度增大是此次大雾形成的主要原因。

Based on the conventional meteorological observation data,the circulation background,influence system,atmospheric structure characteristics,meteorological element field and physical conditions of the two heavy fog weather processes in Shizuishan on September 10 and 14,2020 were comprehensively analyzed.The results showed that the two heavy fog weather events were formed by the effects of the weather systems such as high-altitude shallow ridge,low-pressure trough and cold advection.Among them,500 hPa mid latitude westerly air flow,850 hPa weak southerly air flow,the ground was located at the rear of the weakened cold high pressure,which provided a favorable environmental field for the formation of foggy weather,accompanied by clear sky radiation,and was a typical radiation fog.The main reason for the formation of the heavy fog was that the humidity of the near ground layer increased due to the rainfall in the early stage.