Impacts on Meteorological Parameters and Pollutants by Aerosol Direct Radiative Effect Over Tianjin, China

Abstract

The direct radiative effect (DRE) of anthropogenic aerosols on meteorological elements and pollutants over Tianjin, China, was investigated using a fully coupled meteorology-chemistry model [Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem)] for the entire year of 2021. The results showed that the ground solar radiation decreased from 208.84 W m−2 to 194.52 W m−2 due to DRE in Tianjin, and the percentage of the reduction was 6.86%. The reduction of ground solar radiation resulted in a 0.90% decrease in temperature, 1.13% decrease in boundary layer height, and 6.01% decrease in visibility, respectively, and a 0.80% increase in relative humidity. Changes in meteorological parameters changed the diffuse conditions of pollutants, leading to an increase of PM2.5. Higher concentration of pollutants leads to stronger DRE, and the percentages of changes caused by DRE on polluted days are higher than those on clean days. The DRE influence on pollutants can be summarized as a weather → aerosol → weather → air quality circulation mechanism. The DRE had more severe influence on meteorological elements and pollutants on foggy days. With the emission reduction of pollutants, the influence of the DRE has declined.