The impacts of Saharan dust on cloud microphysical and radiative processes in Hurricane Nadine (2012) during HS3

The Hurricane and Severe Storm Sentinel (HS3) was a multiyear field campaign (2012-14) with the goal of improving understanding of hurricane formation and intensity change. One of HS3's primary science goals was to obtain measurements to help determine the extent to which the Saharan air layer (SAL) impacts storm intensification. In 2012, HS3 used the NASA unmanned Global Hawk aircraft to obtain measurements within Nadine and the adjacent SAL air mass. It is 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 can exert considerable influence on the microphysical properties of both liquid and ice clouds. On the other hand, these same aerosols also have a direct effect on how longwave and shortwave radiation 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 a need to assess the combined aerosol effects on microphysics and radiation. For this study, the Goddard microphysics and longwave/shortwave schemes in WRF have been coupled in real-time with the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model in WRF-Chem to account for the direct (radiation) and indirect (microphysics) impacts. Results from the recent simulations of Hurricane Nadine (2012) during HS3 will be presented. This presentation will focus on comparisons between HS3 observations and model output, as well as dust microphysical and radiative impacts on Nadine.