2022年3月17日海西州大风沙尘天气过程分析

Analysis of a Strong Sind and Dust Weather Processes in Haixi Prefecture of Qinghai Province on March 17,2022

利用青海省海西州8个国家地面气象观测站常规地面资料及格尔木、都兰、茫崖3个站探空资料,对2022年3月17日海西地区沙尘天气特征进行了分析。结果表明:此次过程影响范围广,持续时间长,沙尘天气日变化明显且有东强西弱的特点;过程中500 hPa上海西州境内等压线呈西北-东南向,位势梯度较大,同时高空有强劲的急流;茫崖、格尔木和都兰逆温层被破坏后约3 h、4 h、1 h后各站出现沙尘天气;此次过程中冷空气进入海西地区的速度较快且冷空气强度不大,西部各站点日3 h变压较东部而言变化幅度偏小强度偏弱,变化幅度较东部小约1~2 hPa,变化时间较东部长约3 h;过程中500 hPa上有冷温槽,东部温度梯度为1.3℃/100公里,等温线密集且东密西疏和3 h变压梯度东高西低是此次大风沙尘天气过程东强西弱的主要原因。分析结果可为今后类似大风沙尘天气过程预报提供参考依据。

Based on the conventional ground data of eight national surface meteorological observation stations in Haixi Prefecture of Qinghai Province,and the sounding data of Golmud,Dulan and Mangya,the characteristics of sand and dust weather in Haixi on March 17,2022 were analyzed.The results showed that the process had a wide range of influence,a long duration,and obvious diurnal variation of sand and dust weather,which was strong in the east and weak in the west;The isobars in Haixi Prefecture at 500hPa in the process were in a northwest-southeast direction,with a large geopotential gradient,and there was a strong jet stream in the upper altitude;About 3 hours,4 hours,and 1 hour after the destruction of the inversion layer of Mangya,Golmud and Dulan,there was a dust weather at each station;In the process the cold air entered Haixi area fastly and its intensity was not large,the daily 3h pressure change range of the stations in the west was smaller than that in the east,the change range was about 1-2 hPa smaller than that in the east,and the change time was about 3h longer than that in the east;There was a cold temperature trough at 500hPa in the process,and the temperature gradient in the east was 1.3℃/100 km,the dense isotherm and the 3-hour pressure gradient of high in the east and low in the west were the main reasons for the strong east and weak west of the windy and dusty weather process.The analysis results could provide a reference for the prediction of similar windy and dusty weather processes in the future.