青海高原一次沙尘重污染天气成因分析  

Analysis of the Transmission Characteristics of a Heavy Dust Pollution Weather in Qinghai Plateau

作　　者：郭晓宁 马秀梅 张青梅[1] 谈昌蓉 马元仓[1] 王娜 王钰 GUO Xiaoning;MA Xiumei;ZHANG Qingmei;TAN Changrong;MA Yuancang;WANG Na;WANG Yu(Meteorological Observatory of Qinghai Province,Xining 810001,China;Eco-Environmental Monitoring Center of Qinghai Province,Xining 810007,China)

机构地区：[1]青海省气象台,青海西宁810001 [2]青海省生态环境监测中心,青海西宁810007

出　　处：《中国环境监测》2020年第1期45-54,共10页Environmental Monitoring in China

基　　金：青海省科技厅应用基础研究项目(2018-ZJ-723);2018年青海省省级大气污染防治专项(2018015);青海省气象台2018年科学研究项目(2018-03)

摘　　要：利用常规观测的卫星云图资料、地面资料、探空资料、地面污染物监测数据,结合拉格朗日粒子扩散模型(LPDM)污染源溯源方法,对2018年2月青海高原一次沙尘重污染天气的主要成因以及沙尘传输特征进行了分析。结果表明:此次重污染天气受高空低槽东移影响,在300~700 hPa形成了强烈的辐散下沉,槽后的高空急流随之东移。在其东移过程中,受高空急流动量下传及偏北气流中的冷空气共同作用,青海东部出现了大风沙尘天气。边界层中逆温层的存在是此次污染天气持续的重要原因之一,加之未出现明显降水,不利于大气污染物的扩散。通过运用LPDM对此次污染天气的运动轨迹进行分析来看,气团影响的模拟高度层距离地面100 m,气团层趋势一致。研究区地处青藏高原,海拔较高,0~100 m高度的气团足迹可以反映出PM 10污染气团的输送路径。同时,0~100 m是主要的人为源排放空间,也是对人类活动影响较大的区域。气团足迹与PM 10浓度的变化趋势一致,即青海东部沙尘污染主要是由河西走廊沙尘倒灌进入青海东部导致,这与天气学分析结果一致。Using satellite cloud data,ground data,sounding data and ground pollutant monitoring data,combined with Lagrangian particle dispersion model(LPDM)pollution source tracing method,the main causes of a heavy dust pollution weather in eastern Qinghai Plateau in February 2018 and the characteristics of dust transmission were analyzed.The results showed that the heavily polluted weather was affected by the eastward movement of the high altitude and low trough.A strong divergence subsidence was formed between 300 hPa and 700 hPa.The upper jet flows behind the trough moved eastward.During the eastward movement,strong wind and dust weather appeared in eastern Qinghai due to the downward transmission of the high altitude jet flow and the cold air in the northward airflow.The existence of the inversion layer in the boundary layer was one of the important reasons for the persistence of the polluted weather.In addition,there was no obvious precipitation weather,which was not conducive to the diffusion of atmospheric pollutants.From the analysis of the trajectory of the polluted weather by LPDM,it can be seen that the simulated altitude affected by the air mass was 100 meters away,and the trend of the air mass layer was the same.The study area is located in the Qinghai-Tibet Plateau,with a high altitude.The air mass footprint of 0-100 meters can reflect the transport path of PM 10 polluted air mass.At the same time,0-100 m is the main anthropogenic source of emissions,and has a greater impact on human activities in the region.The change of air mass footprint was consistent with the change of PM 10 concentration.The dust pollution in eastern Qinghai was mainly caused by the dustfall from Hexi Corridor into eastern Qinghai,which was consistent with the synoptic analysis.

关 键 词：沙尘 污染 青海 拉格朗日粒子扩散模型 传输特征 

分 类 号：X830.2[环境科学与工程—环境工程]