2020年12月湖南一次持续性重污染天气过程气象成因和数值模拟分析  

Meteorological causes and numerical simulation analysis of a typical persistent heavy pollution weather event in Hunan in December 2020

作　　者：赵恩榕 唐杰 陶雅琴 潘筱龙 杨云芸 张琴 ZHAO Enrong;TANG Jie;TAO Yaqin;PAN Xiaolong;YANG Yunyun;ZHANG Qin(Hunan Meteorological Observatory,Changsha 410118;Hunan Provincial Key Laboratory of Meteorological Disaster Prevention and Mitigation,Changsha 410118;Hunan Environmental Monitoring Center,Changsha 410014;State Environmental Protection Key Laboratory of Monitoring for Heavy Metal Pollutants,Changsha 410014)

机构地区：[1]湖南省气象台,长沙410118 [2]气象防灾减灾湖南省重点实验室,长沙410118 [3]湖南省环境监测中心站,长沙410014 [4]国家环境保护重金属污染监测重点实验室,长沙410014

出　　处：《环境科学学报》2024年第7期327-339,共13页Acta Scientiae Circumstantiae

基　　金：湖南省气象局创新发展专项(No.CXFZ2024-FZZX40,CXFZ2023-FZZX27);中国气象局2024年复盘总结专项(No.FPZJ2024-091);中国气象局决策气象服务专项(No.JCZX2023008);湖南省气象台青年创新基金科研项目(No.QNJJ202202)。

摘　　要：综合利用逐小时主要污染物浓度监测数据和各类气象观测数据,结合HYSPLIT的后向轨迹模式、PSCF分析及中尺度天气数值模式(WRF),对2020年12月18—28日湖南省一次持续时间长、影响范围广的重污染天气过程的气象条件演变特征、气象成因及地形影响进行综合分析.结果表明:中高纬多低槽阶段性东出引导低层冷空气活动频繁是此次远距离污染物传输的主要原因,江南高空环流平直,江汉、洞庭湖及湘江流域复杂地形影响是本次过程污染物聚集的主要原因;北方地区持续低温,湖南近地面温度较低配合逆温的存在、持续偏北风以及后续小风的维持、逆湿层的存在、50%~80%的相对湿度,是此次污染持续并爆发的重要条件.后向轨迹进一步验证了此次重污染天气过程是偏北风输入的外来源和静稳天气形势下本地源累积的共同结果,且发现本地源是本次大气污染过程的主要潜在源,湖北中东部、河南南部、江西西北部的区域输送也有一定贡献.WRF敏感性试验表明,大别山、幕连九山脉对华北、华东污染物向湖南传输具有阻挡作用,这指示人们在对污染物浓度进行业务预报时,也需关注地形的影响.By integrating hourly major pollutants monitoring data,various meteorological observations,the backward trajectory model HYSPLIT,PSCF analysis,and the mesoscale weather numerical model(WRF),this study extensively analyzes the evolution of meteorological conditions,underlying meteorological factors and topographic effects of a long-duration heavy pollution event in Hunan Province from December 18 to 28,2020.During this event,the long-distance pollutant transport is led by the frequent activity of low-level cold air,which is guided by the frequent eastward movement low troughs in the middle and high latitudes.And,the accumulation of pollutants is a combined result of the flat high-altitude circulation over the Jiangnan region,and the complex terrain in Jianghan Plain,Dongting Lake and Xiangjiang River Basin.Alongside the persistent low temperature in the norther regions,several weather conditions within Hunan significantly influence the maintenance and outbreak of this pollution event,including the low temperature and inversion layer near the ground,the continuous northerly wind and the subsequent light wind,humidity inversion layer and a suitable relative humidity at 50% ~ 80%.The results of backward trajectory further verify that the heavy pollution event is the result of the accumulation of external sources carried by northerly wind and local emissions under stable weather conditions.The local pollutant emission is the primary source of this event,with contribution from the regional transport from central and eastern Hubei,southern Henan and northwestern Jiangxi.WRF sensitivity experiments reveal that the Dabie Mountains,Mufu Mountains and Jiuling Mountains act as barriers blocking the transport of pollutants from North China and East China to Hunan,highlighting the importance of considering the terrain effect when forecasting pollutant concentrations.

关 键 词：细颗粒污染物(PM_(2.5)) 后向轨迹 PSCF分析 风廓线雷达 中尺度数值模式(WRF) 

分 类 号：X51[环境科学与工程—环境工程] X16