北京市一次先PM_(2.5)后沙尘污染过程特征及预报效果分析  

A Pollution Process of PM_(2.5) and Ensued Sand-Dust in Beijing:Characteristics and Analysis of Forecast Effects

作　　者：潘锦秀 刘保献 安欣欣 李云婷 孙峰 郭元喜 张章 王莉华 PAN Jinxiu;LIU Baoxian;AN Xinxin;LI Yunting;SUN Feng;GUO Yuanxi;ZHANG Zhang;WANG Lihua(Beijing Key Laboratory of Airborne Particulate Matter Monitoring Technology,Beijing Municipal Ecological and Environmental Monitoring Center,Beijing 1(XX)48,China)

机构地区：[1]北京市生态环境监测中心大气颗粒监测技术北京市重点实验室,北京100048

出　　处：《环境科学与技术》2022年第4期109-115,共7页Environmental Science & Technology

基　　金：国家重点研发计划课题(2017YFC0213004)。

摘　　要：该文利用韩国天气图、中国气象局气象要素、PM_(2.5)和PM_(2.5)质量浓度及NAQPM_(2.5)S模式模拟资料对2021年3月8-17日的一次先PM_(2.5)污染后沙尘传输作用的污染过程对空气质量影响、形成原因及数值模型预报效果进行了初步分析。结果表明:此次污染过程造成北京市空气质量持续10 d超标,污染过程主要经历2个不同的阶段,第一阶段为以PM_(2.5)为首污阶段(8-14日):不利的大气扩散条件叠加区域传输影响,导致北京市持续68 h空气重污染,PM_(2.5)峰值浓度达到264μg/m^(3);第二阶段为沙尘影响阶段,前期受上游强沙尘影响而形成的PM_(2.5)峰值浓度超过7 000μg/m^(3)的严重污染过程,后期在西南风作用下受沙尘回流影响。此次污染过程的成因PM_(2.5)污染时段为静稳、高湿度、偏南风的不利大气扩散条件影响,数值模式结果表明区域传输达到69%;沙尘污染时段随着蒙古气旋的发展引起冷空气南下造成华北地区、华中、华东等地大面积的沙尘天气,而后暖空气盛行的一支南风造成沙尘回流重新影响华北地区。NAQPM_(2.5)S模式对PM_(2.5)污染阶段预报效果较好,而受本身技术机制、污染源清单准确性等因素影响对沙尘过程导致漏报。During the period of March 8-17, 2021, the air pollution of PM_(2.5) and ensued sand-dust took place in Beijing.This paper intended to depict the pollution process as well as the preliminary analysis on the effectiveness of the pollution forecast. Thus, based on the information of the weather map from Korea, meteorological elements of the China Meteorological Administration, and mass concentrations data of PM_(2.5) and PM_(2.5), and the data for the forecast by NAQPM_(2.5)S model simulation,the influence of the pollution process of PM_(2.5) pollution followed by sand transport on air quality, the formation mechanism and the prediction effectiveness of the numerical model were analyzed. Results of the analysis showed that this pollution process caused worsened air quality of Beijing, exceeding the relevant air quality standard for as long as ten days;the pollution process experienced two phases: the first one was PM_(2.5) pollution, and during the primary stage (March 8-14), adverse atmospheric diffusion conditions superimposed the regional transmission effect, resulting in severe air pollution in Beijing for 68 h,with the peak concentration as high as 264μg/m^(3);and the second was the impacts of sand-dust, i.e. the earlier upwind strong dust storm caused the peak PM_(2.5)concentration exceeding 7000μg/m^(3), and later affected by southwest wind, the sand-dust backflow occurred. The cause of PM_(2.5)pollution process was analyzed: owing to the weather condition of static stability and high humidity, as well as the adverse atmospheric diffusion condition due to the southerly winds, and according to the calculation by the numerical model, the regional transmission was up to 69%;and during the dust pollution period, with the development of the Mongolian cyclone, the cold air moved southward resulting in sand-dust weather over a large area covering north,central and east China, and then the warm south-wind was prevailing leading to the return of sand-dust which affect north China once more. To sum up, NAQPM_(2.5)S

关 键 词：北京 PM_(2.5) 沙尘 静稳天气 回流 NAQPM_(2.5)S 

分 类 号：X513[环境科学与工程—环境工程]