Impacts of atmospheric circulations on aerosol distributions in autumn over eastern China: observational evidences

Abstract

Abstract. Regional heavy pollution events in East China (110–122° E, 28–40° N) are the main environmental problems recently because of the high urbanization and rapid economic development connected with too much emissions of pollutants. However, appropriate weather condition is another factor which cannot be ignored for these events. In this study, the relationship between regional pollution status and larger scale atmospheric circulations over East China in October is investigated using ten-year (2001–2010) MODIS/Terra aerosol optical depth (AOD) product and the NCEP reanalysis data together with case analysis and composite analysis. Generally, statistics in East China show values of mean AOD vary from 0.3 to 0.9 in October over the region, and larger AOD variances are accompanied with the distribution of higher average AOD. Eighteen pollution episodes (regional mean AOD > 0.6) and ten clean episodes (regional mean AOD < 0.4) are selected and then categorized into six polluted types and three clean types, respectively. Each type represents different weather pattern associated with the combination of lower and upper atmospheric circulation. Generally, the uniform surface pressure field in East China or steady straight westerly in middle troposphere, particularly the rear of anticyclone at 850 hPa, are typical weather patterns responsible for heavy pollution events, while clean episodes occur when strong southeastward cold air advection prevails below the middle troposphere or air masses are transported from sea to the mainland. The above studies are especially useful to the government decision make on balance of economic activities and pollution mitigations.

PM2.5 Pollution Modulates Wintertime Urban Heat Island Intensity in the Beijing‐Tianjin‐Hebei Megalopolis, China

“…In addition, some specific synoptic patterns might also cause noticeable changes in both UHII and PM 2.5 . Synoptic patterns can affect air quality episodes which are already expressed through the meteorological variables (e.g., temperature, wind speed, rainfall, and cloud cover), and thus, these variables can represent a certain synoptic situation over a given region (Kassomenos et al, ; Luo et al, ; Miao et al, , ; Ning et al, , ; Shahgedanova et al, ; Wang, Liu, et al, ; Yang Yim et al, ; Zheng et al, ). The possibly different associations between the UHII and PM 2.5 under different synoptic patterns will be the focus of a future study.…”

Characteristics of Heavy Particulate Matter Pollution Events Over Hong Kong and Their Relationships With Vertical Wind Profiles Using High‐Time‐Resolution Doppler Lidar Measurements

“…According to previous studies (Borge et al, 2007;Guo et al, 2017;Osborne et al, 2019;Zheng et al, 2015), backward trajectories for identified particulate matter pollution episodes were computed using Numerical Atmospheric-dispersion Modelling Environment to identify the impacts of transboundary air pollution and local PM pollution in Hong Kong (Jones et al, 2007). Briefly, the Numerical Atmospheric-dispersion Modelling Environment model is a Lagrangian transport model that is driven by model forecast winds or reanalysis data with variable spatial resolutions (Walters et al, 2017).…”

Mechanism of Spatiotemporal Air Quality Response to Meteorological Parameters: A National-Scale Analysis in China

“…The negative impact of relative humidity strengthened gradually from north to south, corresponding to the more humid climate. In addition to the clean air mass from the sea, strong southeastward cold-air advection prevailed in autumn, maintaining wind speed as a dominant factor mitigating air pollution in eastern and southern coastal regions [44].…”