汾渭平原东部运城市空气污染变化特征及其气象因素影响分析  

Study on Characteristics and Impact of Meteorological Conditions on Air Pollution Variation in Yuncheng of Eastern Fenwei Plain

作　　者：周涛 周青[2] 张勇[2] 张传江[3] 李津 赵华 张茜茹 ZHOU Tao;ZHOU Qing;ZHANG Yong;ZHANG Chuanjiang;LI Jin;ZHAO Hua;ZHANG Xiru(Yuncheng Meteorological Service,Shanxi,Yuncheng 044000;Meteorological Observation Center of CMA,Beijing 100081;Jiangxi Climate Center,Nanchang 330096;Shanxi Meteorological Service Center,Taiyuan 030002)

机构地区：[1]山西省运城市气象局,运城044000 [2]中国气象局气象探测中心,北京100081 [3]江西省气候中心,南昌330096 [4]山西省气象服务中心,太原030002

出　　处：《气象科技》2022年第4期574-583,共10页Meteorological Science and Technology

基　　金：陕西省气象局秦岭和黄土高原生态环境气象重点实验室开放研究基金课题(2021K-10);山西省气象局重点项目(SXKZDTC20226302);山西省面上项目(SXKMSTQ20217137)共同资助。

摘　　要：本文综合利用2015—2020年地面气象观测资料、欧洲中心ERA5再分析资料及大气环境监测数据,分析了汾渭平原东部运城市污染物浓度的变化特征以及与天气形势和气象要素的关系。结果表明:(1)2015—2020年期间运城市PM_(2.5)、PM_(10)、SO_(2)、NO_(2)、CO 5种污染物年平均浓度呈下降趋势,而O_(3)浓度呈上升趋势;(2)冬季和夏季空气质量相对较差,首要污染物分别是PM_(2.5)和O_(3),边界层高度的变化与近地层风向风速、污染物浓度的关系密切,冬季(夏季)PM_(2.5)(O_(3))污染较重时边界层高度较低(较高),以东北风(东南风)为主,风速偏小(偏大);(3)最后利用自组织映射神经网络(SOM)算法分别对冬夏925 hPa位势高度场进行天气分型并开展不同天气形势下污染物浓度与气象要素的变化对比研究,发现冬季污染时以静稳天气为主,低层弱东北风将污染物输送至运城市,而夏季O_(3)污染较重时受热低压形势控制,利于O_(3)前体物汇合,太阳辐射较强时O_(3)浓度较高。Based on the observation from Automatic Weather Stations(AWS) and atmospheric environment monitoring stations,along with ERA5 reanalysis data between 2015 and 2020,the variation characteristics of main pollutants,as well as the relationship between synoptic pattern and meteorological elements in Yuncheng,a city of the eastern Fenwei Plain are comprehensively analyzed.The results show that the annual average concentrations of PM_(2.5),PM_(10),SO_(2),NO_(2),and CO in the city from 2015 to 2020 show a downward trend,while the annual average concentration of O_(3) shows an upward trend.The air quality in winter and summer is relatively poor,with PM_(2.5) and O_(3) as the major pollutant in winter and summer,respectively.There is a close relationship between the variation of Boundary Layer Height(BLH) and wind direction,wind speed and pollutant concentration in the eastern Fenwei Plain.In the winter,heavy PM_(2.5) pollution usually happens on the days with low BLH and relatively small northwesterly prevailing winds.In contrast,the heavy pollution in summer usually occurs on the days with tall BLH and relatively large south-easterly prevailing winds.Finally,using the Self-Organizing Map neural(SOM) network algorithm,the synoptic patterns are identified from geopotential height fields at the height of 925 hPa in winter and summer,and the relationship between the variation of pollutant concentration and meteorological elements under different synoptic patterns are elucidated.It is shown that the weather partterns characterized by weak northeasterly prevailing winds are found to be associated with heavy PM_(2.5) pollution,which is transported from the heavily polluted regions to Yuncheng,while O_(3) pollution in summer is linked to the synoptic pattern featured by heat low pressure and strong radiation,which is conductive to the gathering of O_(3) precursor.

关 键 词：运城市 PM_(2.5) O_(3) 污染 气象因素 天气分型 SOM 

分 类 号：X51[环境科学与工程—环境工程] P412[天文地球—大气科学及气象学]