Significant Influence of Aerosol on Cloud-to-Ground Lightning In Sichuan Basin

The effects of aerosols under special terrain on lightning activities in Sichuan Basin (SB) is studied using the cloud-to-ground (CG) lightning data and aerosol optical depth (AOD) data from 2010 to 2018. Interesting results show that although lightning occurs frequently in the west of the basin due to the great topographic drop, the lightning activity shows a significant downward trend during the study period. Coincidentally, the value of AOD in the basin also showed a significant downward trend. We speculate that the reduction of aerosols contributes to the reduction of lightning under this terrain which is very conducive to lightning occurrence. Since the lightning activity in SB generally occurs at night, the aerosol-radiation interaction (ARI) has an insignificant influence on the occurrence of convection. Under this condition, it can be inferred that the aerosol-cloud interactions (ACI) is dominant over SB region, which could better support the decrease of lightning production