Study of Persistent Haze Pollution in Winter over Jinan (China) Based on Ground-Based and Satellite Observations

A comprehensive study of the formation process of haze events in the Jinan area of China during winter is conducted based on the ground-based and satellite observation data from 1 December 2020 to 12 January 2021. According to variation of pollutant concentrations, two typical types of haze pollution are found in the Jinan area. During the type 1 haze pollution, the PM2.5 concentrations are greater than 75 mu gm(-3) and less than 115 mu gm(-3) with a short duration. The haze is mainly caused by local pollutant emissions and the accumulation of pollutants transported from areas around Jinan. By contrast, type 2 haze pollution episodes have a long duration and peak PM2.5 concentrations between 150 mu gm(-3) and 250 mu gm(-3), which is considered heavy pollution. Type 2 haze pollution is mainly caused by a mixture of long-range transported dust with locally emitted pollutants. Moreover, the unfavorable meteorological factors such as stable inversion layer, continuous cold high-pressure system, high relative humidity, and low wind speed play an important role in the formation of both types of haze pollution. In addition, there are significant photochemical processes during the haze pollutions. According to satellite data, the AOD in Jinan and surrounding areas is maintained at a high-level during haze pollution. It indicates that the local pollution is often accompanied by regional pollution during haze pollution events. This study reveals the formation process of haze pollution and promotes the study of regional climate change, which can provide guidance to the government in the prevention and control of haze pollution in East China.

Automated summary

This study analyzed ground-based and satellite data from December 1, 2020 to January 12, 2021 to investigate the formation process of haze events in Jinan area during winter. Two typical types of haze pollution were identified in the area, with different causes and characteristics. Local pollutant emissions and pollutants transported from surrounding areas contribute to type 1 haze pollution, while a mixture of long-range transported dust and locally emitted pollutants cause type 2 haze pollution. Unfavorable meteorological factors such as stable inversion layer, continuous cold high-pressure system, high relative humidity, and low wind speed play crucial roles in the formation of both types of haze pollution.