Reveal persistent haze pollution episodes in hefei: a perspective from ground-based and satellite observation

Haze has a severe impact on public health and daily life. The effective monitoring of atmospheric environment and regional air quality can be achieved through the comprehensive utilization of ground-based stations and satellite observations. By analyzing pollutant data, ground-based lidar observations, VIIRS and CALIPSO satellite images, meteorological data, and backward trajectory patterns, the three winter aerosol pollution events are studied in the Hefei region from 2018 to 2020. The results reveal similar median PM_2.5 concentrations during the three aerosol pollution events, approximately 82 µg/m³, with aerosol extinction coefficients of about 0.8 and AOD values consistently exceeding 1. However, the formation processes and pollution mechanisms of the three haze events are different. Furthermore, the favorable meteorological conditions for aerosol pollution in the Hefei region during winter are the combined effects of surface cold high-pressure systems and low wind speeds. This study reveals the mechanisms underlying different aerosol pollution events in the winter season of the Hefei region, providing new reference and perspectives for aerosol pollution research and prevention.