The impact of Saharan dust on the intensity of 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. HS3 observations suggested that the SAL air generally remained outside the outermost convection of the storm on its eastern side. However, on the day Nadine just reached hurricane intensity on 15 September, there was some evidence (e.g., low equivalent potential temperatures) for the presence of SAL air in the interior of the storm in the boundary layer. However, it was not possible to quantify the SAL's impact. In this study, the Goddard version of the Weather Research and Forecasting model with interactive aerosol-cloud-radiation physics is used to identify the role of Saharan dust using 30-member ensemble simulations of Nadine with and without the aerosol interactions. Preliminary conclusions related to the impact of the SAL on the evolution of Nadine will be presented.