山谷风对太原市污染物质量浓度的影响  

Influence of Valley Wind on the Mass Concentration of Pollutants in Taiyuan

作　　者：李艳红[1] 赵彩萍[1] 李梦军[1] 荆肖军[1] 李兆奇 Li Yanhong;Zhao Caiping;Li Mengjun;Jing Xiaojun;Li Zhaoqi(Taiyuan Meteorological Office,Taiyuan 030082,China)

机构地区：[1]太原市气象局,太原030082

出　　处：《气象与环境科学》2022年第3期22-28,共7页Meteorological and Environmental Sciences

基　　金：中国气象局预报员专项(CMAYBY2020-017);山西省气象局科研项目(SXKMSFW20195625)。

摘　　要：为揭示山谷风对太原城区局地风和污染物输送、扩散的重要作用,利用太原市2014年12月至2017年11月地面风场和同期PM_(10)、PM_(2.5)和O_(3)质量浓度逐时及日平均资料,分析山谷风对污染物浓度的影响。结果表明:(1)受山地—平原的共同作用,太原市城区实测风表现出明显的山谷风特征,白天以偏南风为主,夜间以偏北风为主,风向转换的时间在日出日落前后。(2)2014年12月至2017年11月期间太原市有山谷风日520天,占总天数的48%,春夏季的较少,秋冬季的较多。(3)山谷风与实测风风速分布及昼夜变化相近,无山谷风日风速日变化幅度较小,其他类型天气风速较大,受局地环流影响较小。(4)PM_(10)和PM_(2.5)质量浓度山谷风日的最高,无山谷风日的次之,其他类型的最低。(5)个例研究表明,山谷风对污染物浓度及其分布有重要影响,污染物浓度随山谷风环流呈现明显的日变化。In order to reveal the important role of valley wind on the local wind field and pollutant transport and diffusion in Taiyuan city,the influence of valley wind on pollutant concentration is analyzed by using the surface wind data and the hourly and daily average data ofρ(PM_(10)),ρ(PM_(2.5))andρ(O_(3))from December 2014 to November 2017.The results show that:(1)Due to the joint action of mountain and plain,the measured wind field in Taiyuan city shows obvious valley wind features.The wind direction is mainly southerly in the daytime but northerly in the nighttime.The time of wind direction conversion is around sunrise and sunset.(2)From December 2014 to November 2017,there were 520 days of valley wind days in Taiyuan,accounting for 48%of the total days.There were fewer valley winds in spring and summer,but more in autumn and winter.(3)The distribution and diurnal variation of valley wind speed are similar to that of measured wind speed.The diurnal variation range of daily wind speed without valley wind is weak.The wind speed in other types of weather is larger,less affected by local circulation.(4)The pollutant concentrations ofρ(PM_(10))andρ(PM_(2.5))in the valley wind days are the highest,followed by that in the non-valley wind days,and the lowest concentration is found in other types of weather.(5)A case study shows that the valley wind circulation has an important influence on the pollutant concentration and its distribution,and the pollutant concentration has obvious diurnal variations with the mountain valley wind circul.

关 键 词：太原 山谷风 污染物 质量浓度 影响 

分 类 号：X51[环境科学与工程—环境工程]