Effects of Different Types of Aerosols on Lightning Properties based on Satellite Observations

Lightning activity is a crucial developing indicator of a convective system, which is generally regarded to be invigorated with increased aerosol loads, although excessive aerosol particles may lead to inhibition of convection and reduction of lightning activity. Aerosols typically affect lightning activities by two generally opposite effects, namely the radiative effect through modulating the convection strength and the microphysical effect through changing the contents of supercooled water and ice particles in clouds, and aerosol types determine the attributes of these two categories of effects. However, the degree of influence under different environmental situations is uncertain; thus, understanding the impact of aerosol types on lightning activities remains a significant challenge. In this study, the effects of different types of aerosols on lightning properties, including lightning density and energy, are investigated over the CONUS by comprehensively analyzing the satellite-derived aerosol and lightning observations from MODIS, CALIOP, and GOES-GLM. The relationship between lightning density and aerosol optical depth (AOD) illustrates a generally monotonous trend in which the lightning density increases with AOD, and reaches a plateau when AOD becomes relatively large. The relationship between lightning energy and AOD, on the other hand, is not monotonous with a turning point at AOD of approximately 0.5. Particularly, it is found that both lightning density and lightning density illustrate distinct relationship trend when aerosol loading increases under different aerosol types. This difference will be further explained by analyzing the convective available potential energy and other meteorological parameters during the convective cloud development processes.