Evaluation of the Hawaii Volcanic SO2 Emission Direct and Indirect Impact on the Downstream Trade Cumulus Regime with NASA Unified WRF model

It is also well known that aerosols in the atmosphere often serve as condensation nuclei in the formation of cloud droplets and ice particles. As a result, these aerosols acting as condensation nuclei exert considerable influence on the microphysical properties of both warm and ice clouds. On the other hand, these same aerosols also have a direct effect on how longwave and shortwave radiations are absorbed in the atmosphere and consequently the heating in the atmosphere and at the surface. Given the complexity of aerosol effects on cloud microphysics and radiation and their subsequent effects on deep convective clouds, there is also a need to assess the combined aerosol effects of microphysics and radiation. In this latest model development, the Goddard microphysics and longwave/shortwave schemes in NASA Unified WRF (NU-WRF) are coupled in real-time with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) in WRF-Chem to account for the direct (radiation) and indirect (microphysics) impact. In this study, NCEP GFS global analysis is used to provide the initial and boundary conditions with aerosol fields provided by the NASA GEOS-5 global analysis to carry out a month long simulation for July 2008.  Regular emission data plus volcanic SO₂ emissions are input and updated every 24 hours. We will present the simulation results with and without aerosol direct and indirect impact and compare with satellite observations. The impacts of Hawaii Volcanic SO₂ Emission are evaluated by looking at the differences between the control (no aerosol) and aerosol simulations.