The Influence of Multi-Scale Atmospheric Circulation on Severe Haze Events in Autumn and Winter in Shanghai, China

Abstract

Severe haze events have many adverse effects on agricultural production and human activity. Haze events are often associated with specific patterns of atmospheric circulation. Therefore, studying the relationship between atmospheric circulation and haze is particularly important for early warning and forecasting of urban haze events. In order to study the relationship between multi-scale atmospheric circulation and severe haze events in autumn and winter in Shanghai, China, we used a T-mode objective classification method to classify autumn and winter atmospheric circulation patterns into six types based on sea level pressure data from 2007 to 2016 in the Shanghai area. For the period between September 2016 and February 2017, we used the Allwine–Whiteman method to classify the local wind in Shanghai into three categories: stagnation, recirculation, and ventilation. By further studying the PM2.5 concentration distribution, visibility distribution, and other meteorological characteristics of each circulation type (CT) and local wind field type, we found that the Shanghai area is most prone to severe haze when exposed to certain circulation patterns (CT1, CT2, and CT4), mainly associated to the cold air activity and the displacement of the high pressure system relative to Shanghai. We also found that the local wind fields in the Shanghai area are dominated by recirculation and stagnation events. These conclusions were further verified by studying a typical pollution process in Shanghai in November 2016 and the pollutant diffusion path using the HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory model) simulation model.

Potential Socioeconomic and Environmental Benefits and Beneficiaries of UAS Atmospheric Profiles from a 3D Mesonet

“…Studies have shown there is a correlation between elevated PM 2.5 pollution and decreasing boundary layer heights as well atmospheric circulation patterns that promote stagnation and recirculation of air masses (Miao et al 2018;Zhao et al 2019). Dry, tropical air masses and stagnation events during the summer have led to ozone nonattainment events throughout the Midwest (Jing et al 2017) and field campaigns like the Lake Michigan Ozone Study (LMOS) and the Ozone Water-Land Environmental Transition Study (OWLETS) have highlighted how nonattainment along coastal areas can be driven by lakeand sea-breeze circulations that bring ozone-rich air inland from shallow pollution rich layers over the water (Abdi-Oskouei et al 2019;Dye et al 1995;Sullivan et al 2019).…”

Collective influences of boundary layer process and synoptic circulation on particulate pollution: A new study in changsha-zhuzhou-xiangtan urban agglomeration of central china

“…Mastering the diffusion and transport laws of pollutants is very important to quantify air pollution levels, meteorological conditions play an important role in the diffusion and transport of pollutants (Li et al, 2012;Mao et al, 2020;Miao et al, 2017;Wang et al, 2016;Zong et al, 2021;Zhao et al, 2019Zhao et al, , 2021aZhao et al, , 2021bSun et al, 2018Sun et al, , 2019. The meteorological conditions mainly include large-scale synoptic circulation and the mesoscale meteorological conditions (Zhou et al, 2018(Zhou et al, , 2019Wang et al, 2022;Russo et al, 2014, Russo et al, 2016.…”

“…The meteorological conditions mainly include large-scale synoptic circulation and the mesoscale meteorological conditions (Zhou et al, 2018(Zhou et al, , 2019Wang et al, 2022;Russo et al, 2014, Russo et al, 2016. Large-scale synoptic circulation determines the specific climatic background of the study area and provides the basic dynamic field for the diffusion and transport of particulate matter (Zhao et al, 2019;Bei et al, 2022;Yan et al, 2022;Gong et al, 2022a, Gong et al, 2022b. Several studies have revealed the relationship between large-scale circulation and particulate pollution (Zhang et al, 2012, Zhang et al, 2012Zhan et al, 2019;Shu et al, 2020).…”

“…Further, the warm wet flow coming from the southwest in front of the trough enhances the hygroscopic growth ability of the aerosol particles and also leads to an increase in the PM 2.5 concentration. Zhao et al, 2019 studied the relationship between autumn and winter haze events and weather circulation in the Yangtze River Delta region and found that severe haze events often occurred when the high-pressure center was located in the northwest and west of Shanghai. A specific large-scale synoptic circulation situation often corresponds to certain mesoscale regional transmission meteorological conditions (Zhou et al, 2019).…”

Analysis of the temporal and spatial pattern of air pollution and the heterogeneity of its influencing factors in central Inner Mongolia from 2016 to 2018

“…Zhou et al (2019) found that air quality is closely related to the synoptic circulation and local wind field affecting a specific area, and conducted a validation analysis in Shanghai, China. They found that the Shanghai area is most prone to severe haze under specific circulation patterns (CT1, CT2, and CT4), mainly related to cold air activity and the displacement of the high pressure system relative to Shanghai (Zhao et al, 2019). At present, there are few studies in arid and semi-arid regions dominated by dust pollution, and in China it is mainly concentrated in the northwest regions (Haijun et al, 2020;Rupakheti et al, 2021).…”