干旱气象 ›› 2021, Vol. 39 ›› Issue (1): 102-111.

• 论文 • 上一篇    下一篇

重庆市荣昌区冬季PM2.5污染的气象因素及区域传输特征

张新科1,胡长金1,何跃2,刘芮伽3   


  1. (1.重庆市荣昌区气象局,重庆荣昌402460;2.重庆市气象台,重庆 401147;
    3.重庆市荣昌区生态环境局,重庆荣昌402460)

  • 出版日期:2021-03-01 发布日期:2021-03-10
  • 基金资助:
    2020年重庆市气象部门业务技术攻关项目“荣昌区空气质量预报方法及污染潜在源区研究”(YWJSGG-202008)资助

Meteorological Influencing Factors and Regional Transmission Characteristic of PM2.5 in the Winter in Rongchang District, Chongqing

ZHANG Xinke1, HU Changjin1, HE Yue2, LIU Ruijia3   

  1. (1. Rongchang Meteorological Service of Chongqing, Rongchang 402460, Chongqing, China;
    2. Chongqing Meteorological Observatory, Chongqing 401472, China;
    3. Rongchang Ecology and Environment Bureau of Chongqing, Rongchang 402460,Chongqing, China)
  • Online:2021-03-01 Published:2021-03-10

摘要: 利用2016—2018年重庆市荣昌区冬季PM2.5质量浓度监测数据,结合地面气象观测资料、L波段探空雷达资料、ERA-Interim 再分析资料及全球资料同化系统(GDAS)数据,并与HYSPILT模型相结合,分析荣昌区冬季PM2.5污染的气象影响因素及区域传输特征。结果表明:(1)2016—2018年荣昌区冬季PM2.5污染超标频率高达56.3%,但空气质量有好转趋势。PM2.5质量浓度日变化有2个峰值,分别出现在12:00和23:00;(2)荣昌区冬季PM2.5污染主要受降水、逆温层、低层风速等气象条件影响。当925 hPa以下和700~600 hPa存在明显逆温层结,500 hPa呈西北气流或平直西风气流,850 hPa以下为偏东北弱风时不利于PM2.5扩散,易发生重度污染天气。日降水量R>2.0 mm时,降水对PM2.5具有明显的正清除,且清除能力随着降水等级的增大而增大,R<1.0 mm 时,降水对PM2.5表现为负清除,微量降水期间不利的扩散条件加之颗粒物吸湿增长作用反而导致PM2.5质量浓度增加,空气质量恶化;(3)荣昌区冬季PM2.5污染主要受距离荣昌区西北和东北方向约300 km范围内的成渝城市群城市间污染物区域输送影响,外域颗粒污染物的传输是荣昌区冬季PM2.5污染的重要原因。

关键词:
关键词:PM2.5污染,
气象条件, 区域传输, 重庆荣昌

Abstract: Based on the mass concentrations of fine particulate matter (PM2.5) in Rongchang District in winter from 2016 to 2018, surface meteorological observation data, L-band radar sounding data, ERA-Interim reanalysis data and GDAS (global data assimilation system) data, combined with the HYSPILT model, the meteorological influencing factors and regional transmission of PM2.5 in winter were analyzed. The results are as follows: (1) The frequency of PM2.5 mass concentration exceeding 75 μg·m-3 was as high as 56.3% in winter in Rongchang District from 2016 to 2018, but the air quality became better year by year. The diurnal variation of the PM2.5 mass concentration in winter had two peak values, appearing at 12:00 and 23:00. (2) PM2.5 pollution was mainly influenced by precipitation, temperature inversion and low-level wind speed. The obvious temperature inversion stratification near 925 hPa and 700-600 hPa in the surface layer, northwesterly or flat westerly airflow on 500 hPa, and weak northeast wind below 850 hPa, were unfavorable to PM2.5 pollutant diffusion and prone to occur severe pollution weather. The precipitation more than 2.0 mm had a clear clearance effect on PM2.5, the scavenging ability increased with the increase of precipitation level. The precipitation less than 1.0 mm had negative effect in the removal of PM2.5. Unfavourable diffusion condition  and hygroscopic growth of particulate matter led PM2.5 mass concentration to increase during micro precipitation period. (3) The PM2.5 pollution situation was mainly affected by the regional transportion between Chengdu and Chongqing urban agglomerations within about 300 km from the northwest and northeast of Rongchang District. The transmission of particulate pollutants in the outer domain was an important cause of PM2.5 pollution in winter in Rongchang District.




Key words: Key words: fine particulate matters (PM2.5), meteorological conditions, regional transmission, Rongchang District, Chongqing