2016年冬季四川盆地一次重度灰霾事件形成机制研究  

Formation and Evolution Mechanisms of A Severe Haze Event in the Sichuan Basin in Winter 2016

作　　者：任鑫冰 杨显玉 文军 王式功 REN Xinbing;YANG Xianyu;WEN Jun;WANG Shigong(College of Atmospheric Sciences,Chengdu University of Information Technology/Sichuan Key Laboratory of Plateau Atmosphere and Environment,Chengdu 610225,Sichuan,China;Chengdu Plain Urban Meteorology and Environment Sichuan Provincial Field Scientific Observation and Research Station,Chengdu 610225,Sichuan,China;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室,四川成都610225 [2]成都平原城市气象与环境四川省野外科学观测研究站,四川成都610225 [3]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029 [4]中国科学院大学地球与行星科学学院,北京100049

出　　处：《高原气象》2024年第3期775-789,共15页Plateau Meteorology

基　　金：国家自然科学基金项目(42175174);成都信息工程大学科技创新能力提升计划项目(KYQN202239);国家留学基金资助项目(CSC202008510035)。

摘　　要：深入理解重度灰霾污染事件的形成和演化机制对于区域尺度空气质量的管控以及霾污染防治政策的制定具有重要的意义。本文应用中尺度气象模式WRF和区域空气质量模型CMAQ,结合实际观测数据,研究了2016年12月23日至2017年1月7日发生在四川盆地成都地区的一次重度灰霾事件。主要分析了在此污染期间气象要素场的时间变化,PM_(2.5)浓度和通风系数的时空变化,量化了各个物理化学过程对PM_(2.5)的相对贡献以及污染源区的分布,以研究此次重污染霾事件的形成和演化机制。研究表明:(1)霾事件期间低温和低风速的环境条件为污染物的积累创造了有利条件。(2)盆地北侧的偏北气流和南侧的偏西南气流以及较低的通风系数(大气的湍流扩散能力弱)是污染物积累的主要原因,成都地区PM_(2.5)浓度在东北气流的作用下达到峰值。污染物的消散主要是因为偏北气流的加强和较高的通风系数(大气的湍流扩散能力强)。(3)此次霾事件中气溶胶过程和排放源的正贡献加强,PM_(2.5)的增加主要在夜间(平流过程和扩散过程的负贡献减弱)且增加幅度更大,使得PM_(2.5)总体上逐渐增加。(4)PSCF和CWT分析表明,在此次霾事件期间,致使成都地区PM_(2.5)浓度升高的主要气流为其东北方向和西南方向的气流,潜在的污染源区在总体上呈东北-西南向的分布状态。Studying the formation and evolution mechanism of heavy pollution haze events is beneficial to control the regional scale air quality and to formulate the prevention policies of severe haze pollution.Based on the WRF-CMAQ model and actual observation data,a severe haze event which occurred in Chengdu of Sichuan Basin from December 23,2016 to January 7,2017 was reproduced.The distribution of temporal and spatial variations of PM_(2.5) concentration and ventilation coefficient,the physical and chemical processes and the distribution of potential pollution source areas were analyzed to study the formation and evolution mechanism of this severe pollution haze event.Major results were as follows:(1)The environmental conditions of low temperature and low wind speed during the haze event created favorable conditions for the accumulation of pollutants.(2)The northerly airflow in the north of the basin,the southwesterly airflow in the south and the lower ventilation coefficient value(weak turbulent diffusion capability of atmosphere)were the main reasons for the accumulation of pollutants.The PM_(2.5) concentration in Chengdu reached the peak under the influence of the northeast airflow.The dissipation of pollutants was mainly because of the strengthening of the northerly airflow and the higher ventilation coefficient value(strong turbulent diffusion capability of atmosphere).(3)The positive contribution of the aerosol process and emission sources in this haze event was strengthened.And the increase in PM_(2.5) was mainly at night(the negative contribution of the advection process and the weak diffusion process)and the magnitude of the increase was greater relative to the decrease,resulting in an overall gradual increase in PM_(2.5).(4)PSCF and CWT analysis showed that the airflows with high PM_(2.5) concentration in Chengdu mainly came from its northeast and southwest directions during this haze event,and the potential pollution source areas were generally distributed in a northeast-southwest band.

关 键 词：霾事件 CMAQ PM_(2.5) 成都 四川盆地 

分 类 号：X513[环境科学与工程—环境工程]