Implication of the Impact of Saharan Dust on Atlantic Tropical Cyclones

The radiative and microphysical properties of Saharan dust are believed to impact the Atlantic regional climate and tropical cyclones (TCs), but the detailed mechanisms remain uncertain. In this study, ensemble global climate simulations are performed from 2002 to 2006 using the Community Atmospheric Model version 5.1 with and without dust emission from the Sahara Desert.By comparing the dust and non-dust scenarios, we find that dust events induce positive mid-level moisture and entropy deficit anomalies, enhancing the TC genesis. On the other hand, the increased vertical wind shear and decreased low-level vorticity and potential intensity by dust inhibit TC formation in the genesis region. The ventilation index shows a decrease in the intensification region and an increase in the genesis region by dust, corresponding to favorable and unfavorable TC activities, respectively. Our results imply significant dust perturbations on the radiative budget, hydrological cycle, and large-scale environments relevant to TC activity over the Atlantic.