Variations in aerosol optical characteristics from SKYNET measurements in Beijing

Atmospheric aerosols have significant impacts on climate and environment, so the study on aerosol optical properties is of great scientific significance for climate change and atmospheric environment. The variations in column-integrated aerosol optical properties over Beijing were investigated from March 2016 to December 2019 based on the SKYNET data products. Higher values of AOD and AE found in summer indicate that it is important to pay more attention to fine particle pollution in summer. By fitting the AOD data of SKYNET with AERONET at same waveband, we found that monthly variations in aerosol optical depth estimated from SKYNET observation were mostly consistent with the AERONET data. Aerosols were divided into several modes according to optical characteristics, which deepen some insight into aerosol optical and radiative properties and revealed that the weak absorption aerosol dominated and contributed much to the radiation transport in Beijing. Data derived from the polarization lidar CALIPSO were combined with aerosol optical depth (AOD) from SKYNET and these results were consistent, which further identified the scientific of data. The random forest algorithm was used to interpolate the missing AOD500nm observations. The original results and the interpolation results were fitted with MODIS respectively, which proved that the random forest algorithm can supplement the missing results well. This work will be of great significance in addressing the impacts of aerosols on climate and environment, and will help reduce the uncertainty of the impacts of aerosols on the Earth's radiation budget. All work will provide scientific support for the prevention and control of specific pollution.

Automated summary

Atmospheric aerosols play a significant role in climate and environment, making the study of aerosol optical properties crucial for understanding climate change and atmospheric conditions. The variations in Beijing's aerosol optical properties were examined based on SKYNET data from March 2016 to December 2019. Higher values of AOD and AE during summer suggest the need to focus on fine particle pollution during this season. Comparisons between SKYNET and AERONET data show consistent monthly variations in aerosol optical depth. The identification of different aerosol modes provides insights into their optical and radiative properties, highlighting the dominance of weakly absorbing aerosols in Beijing's radiation transport. The combination of CALIPSO and SKYNET data further validates the scientific relevance of the findings. The use of the random forest algorithm effectively interpolates missing AOD500nm observations, as confirmed by the fitting with MODIS. This research is of great significance in understanding the impacts of aerosols on climate and the environment and reducing uncertainties in the Earth's radiation budget. It also provides scientific support for pollution prevention and control measures.