Aerosol Indirect Effects on Circulation and Radiative Forcing through Deep Convection Clouds: Long-time Effects

Aerosol-cloud interaction is recognized as one of the key factors influencing cloud properties and precipitation regimes. For deep convection clouds (DCCs), our previous study indicated aerosols could invigorate convection, leading to a strong radiative warming in the atmosphere, a lofted latent heating, and a reduced diurnal temperature difference, all of which could potentially impact regional circulation and modify weather systems. However, those significant effects were examined on a short term (i.e., in the day when the storms occur). To examine the significance of those effects on the longer-term, we conduct monthly simulations at the cloud-resolving scales for the summer convective clouds using the Weather Research and Forecasting (WRF) model coupled with a spectral-bin microphysics (SBM). Our simulations cover summer convection at the southeast of China, US Southern Great Plain (SGP), and the Tropical Warm Pool (TWP) region. We look into the aerosol effects on circulation, vertical heating profiles, macro- and micro-physical properties, and radiative forcing. This investigation will give us a clear idea how significant the aerosol indirect effects are on the long term in the summers at the mid-latitudes and tropics. It is very meaningful towards better understanding aerosol impact on regional weather and climate.