Impacts of Anthropogenic Pollution on Convective Clouds and Precipitation in a Downwind Pristine Environment

Measurements obtained from GoAmazon2014/5 field campaign IOPs suggest that anthropogenic pollution from the mega-city Manaus in Amazonia significantly impacts aerosol properties including number, composition and size distribution in the downwind areas of Manaus. These changes in aerosol properties would impact cloud properties, convection, and precipitation. In this study, we will conduct simulations for such an observed case – March 17, 2014 using the improved chemistry version of the Weather Research Forecasting model (WRF-Chem) coupled with a spectral-bin cloud microphysics to explore how the Manaus plumes modify aerosol properties in the downwind areas and how the changes of aerosol properties impact convection, clouds and precipitation in the influenced area. We will present preliminary results related to the model evaluation with a wide range of observations from ground-based rain gauges, radar, aircraft and TRMM measurements. Some results on the sensitivity tests to examine the significance of the impact of anthropogenic pollution will be presented and discussed.