2020年泰州一次持续性大雾过程的诊断分析

Diagnostic Analysis of a Persistent Foggy Process in Taizhou in 2020

利用地面观测资料、ERA5再分析资料和微波辐射计资料,对2020年2月11—15日泰州地区的一次持续性大雾天气过程进行诊断分析。结果表明:此次大雾天气500hPa前期受纬向偏西气流控制,后期东北冷涡东移南落,多短波槽过境活动,为大雾天气的形成提供了有利的天气背景条件。大雾持续阶段,低层有暖湿气流,辐合辐散过程相间,低层弱辐合上升运动使得湿层可以达到一定的高度并维持,提供了有利的水汽条件,弱辐散下沉运动则为逆温层的形成提供了有利条件。最终大雾消散主要是由于冷空气的入侵,逆温层遭到破坏。

Ground observation data,ERA5 reanalysis data and microwave radiometer data are used to diagnose and analyze a persistent foggy weather process in Taizhou from February 11 to 15,2020.The results show that during the heavy fog,500hPa was controlled by the zonal westward air flow in the early stage,the northeast cold vortex moved eastward and falls southward,and that there were short-wave troughs transit activities in the late stage,which provided favorable weather background conditions for the formation of foggy weather.In the sustained stage of heavy fog,there was a warm and moist flow in the lower layer,the convergence and divergence processes were alternated,the weak convergence upward movement in the lower layer enabled the wet layer to reach a certain height and maintain,which provided favorable moisture conditions,and weak divergence downward movement provided favorable conditions for the formation of the inversion layer.The final dissipation of fog was mainly due to the invasion of cold air and the destruction of the inversion layer.