Journal of Arid Meteorology ›› 2022, Vol. 40 ›› Issue (5): 879-887.DOI: 10.11755/j.issn.1006-7639(2022)-05-0879

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Influence of topography and weather situation on air pollution in Linfen City

PEI Kunning(), WANG Yan(), YAN Shiming, JIANG Yunsheng, GUO Wei   

  1. Shanxi Institute of Meteorological Sciences, Taiyuan 030002, China
  • Received:2021-03-31 Revised:2021-07-27 Online:2022-10-31 Published:2022-11-10
  • Contact: WANG Yan

地形和天气形势对临汾市大气污染的影响

裴坤宁(), 王雁(), 闫世明, 蒋云盛, 郭伟   

  1. 山西省气象科学研究所,山西 太原 030002
  • 通讯作者: 王雁
  • 作者简介:裴坤宁(1995—),女,山西长治人,硕士,助理工程师,主要从事大气环境研究. E-mail: 1872636982@qq.com
  • 基金资助:
    山西省自然基金(201601D011084);山西省自然基金(201901D111465);山西省气象局重点项目(SXKZDDQ20185105);山西省气象局青年基金(SXKQNDW20205241);山西省气象局青年基金(SXKQNDW20217151)

Abstract:

In order to study the transport characteristics of air pollution in Linfen City, based on the hourly air quality index (AQI) data in Linfen City from the Ministry of Ecology and Environment from 2016 to 2017, the six-hour reanalysis data and the global data assimilation system (GDAS) data with a horizontal resolution of 1°×1° from the National Centers for Environmental Prediction (NCEP), the influence of topography and weather situation on air pollution during the 24 pollution processes in Linfen City was analyzed by using backward trajectory clustering analysis of HYSPLIT4 (hybrid single-particle lagrangian integrated trajectory) model. The results are as follows: (1) The sea-level circulation situation during the 24 pollution processes mainly included the following six types: front of Mongolian high pressure bottom type, front of low pressure type, rear of North China high pressure type, front of invert trough near the Hetao area type, uniform pressure field and low pressure belt type. (2) The 24 h and 60 h backward trajectory can represent the impact of topography conditions and weather conditions on pollution in Linfen City, respectively. (3) The 24 h backward trajectories show that the air flow can sink and transport pollutants along the leeward slope of the Lüliang Mountain. The pollution in Linfen City was formed from inverted “concave” shape terrain opening to the south and the southwest wind near the ground. The air flow can also return to Linfen City after touching the surrounding mountains. Among them, the transportation along the subsidence of the Lüliang Mountain from the northwest direction was main. (4) The 60 hour backward trajectories show that the air flow transporting pollutants met with the easterly or southerly airflow under the influence of the weather situation, and then turned back to Linfen City. The pollutant particles hygroscopic grew with the increase of humidity caused by southwesterly or easterly wind. The topography and weather situation have an impact on the transport route of air pollution in Linfen City.

Key words: topography, weather situation, air pollution, Linfen City

摘要:

为了研究临汾市大气污染的输送特征,利用生态环境部发布的2016—2017年临汾市逐小时空气质量指数(air quality index,AQI)、美国国家环境预报中心(National Centers for Environmental Prediction,NCEP)提供的水平分辨率为1°×1°的逐6 h再分析资料和全球资料同化系统(global data assimilation system,GDAS)数据,基于HYSPLIT4(hybrid single-particle lagrangian integrated trajectory)模式,采用气流后向轨迹聚类分析法研究地形及天气形势对临汾市24次污染过程的影响,结果表明:(1)24次污染过程的海平面环流形势主要有以下6种类型:蒙古高压底前部型、低压前部型、华北高压后部型、河套倒槽前部型、均压场和低压带型。(2)模拟后推24 h和60 h的聚类轨迹分别可以代表地形条件和天气形势对临汾市大气污染的影响。(3)模拟后推24 h的聚类轨迹显示,气流可沿吕梁山背风坡下沉输送污染物,向南开口的倒“凹”字型地形配合近地面西南风可造成临汾市污染,也可通过碰触周围山体后折返回流到临汾市。其中,以西北方向沿吕梁山下沉输送为主。(4)模拟后推60 h的聚类轨迹显示,在有利天气形势影响下携带污染物的气流与偏东或偏南的气流相遇后发生转折回流至临汾市,地面西南或偏东风使湿度增加,造成污染物粒子吸湿增长。地形和天气形势均对临汾市大气污染的输送路径有影响。

关键词: 地形, 天气形势, 大气污染, 临汾市

CLC Number: