Vertical Dependency of Aerosol Impacts on Local Scale Convective Precipitation

Aerosol effects on convective precipitation is critical for understanding human impacts on extreme weather and the hydrological cycle. However, even their signs and magnitude remain debatable. In particular, aerosol effects on vertical structure of precipitation have not been systematically examined yet. Combining 6-year space-borne and ground-based observations over the North China Plain, we show a boomerang-shape aerosol effect on the top height of convective precipitation, from invigoration to suppression. Further analyses reveal that the aerosols play distinct effects on precipitation rate at different layers. Particularly, near surface precipitation rate shows no significant responses to aerosol and precipitation-top height due to strong evaporation. The competition of energy between released from condensation and freezing and absorbed by evaporation contributes to different responses of precipitation-top height to aerosol and can explain the boomerang-shape aerosol effect.

Automated summary

Understanding the effects of aerosols on convective precipitation is crucial for assessing the impact of human activities on extreme weather events and the hydrological cycle. However, the exact nature and magnitude of these effects are still a subject of debate. In this study, using a combination of satellite and ground-based observations over the North China Plain, we found a boomerang-shaped aerosol effect on the top height of convective precipitation, ranging from invigoration to suppression. Further analysis revealed that aerosols have distinct impacts on precipitation rate at different layers, with near surface precipitation rate showing no significant response to aerosols and precipitation-top height due to strong evaporation. The competition between energy released from condensation and freezing and energy absorbed by evaporation can explain the observed boomerang-shaped aerosol effect.