Skip to main content
U.S. flag

An official website of the United States government

Impacts of Cloud Microphysics Parameterizations on Simulated Aerosol-Cloud-Interactions for Deep Convective Clouds over Houston

Presentation Date
Tuesday, December 8, 2020 at 5:48am



Aerosol-cloud interactions remain largely uncertain in predicting their impacts on weather and climate. Cloud microphysics parameterization is one of the factors leading to the large uncertainty. Here we investigate the impacts of anthropogenic aerosols on the convective intensity and precipitation of a thunderstorm occurring on 19 June 2013 over Houston with the Chemistry version of Weather Research and Forecast model (WRF‐Chem) using the Morrison two-moment bulk scheme and spectral-bin microphysics (SBM) scheme. We find that the SBM predicts a deep convective cloud agreeing better with observations in terms of reflectivity and precipitation compared with the Morrison bulk scheme that has been used in many weather and climate models. With the SBM scheme, we see a significant invigoration effect on convective intensity and precipitation by anthropogenic aerosols mainly through enhanced condensation latent heating (i.e., the warm-phase invigoration). Whereas such effect is absent with the Morrison two-moment bulk microphysics, mainly due to limitations of the saturation adjustment approach for droplet condensation and evaporation calculation.