Impacts of Nucleating Aerosols on the Evolution of an Idealized Tropical Cyclone

A large number of Atlantic tropical cyclones (TCs) originate as mesoscale convective vortices (MCVs) that form over the eastern Atlantic. These vortices are often observed to interact with the Saharan Air Layer (SAL). To study the impacts of aerosols embedded in the SAL on the evolution of TCs, a series of numerical simulations initialized with an idealized pre-TC MCV are conducted using the Regional Atmospheric Modeling System (RAMS) with 2 km horizontal resolution on the inner domain. The vortex matures into a hurricane in a zero wind environment. Vertical profiles of cloud condensation nuclei (CCN), giant CCN (GCCN) and ice nuclei (IN) are constructed using observations from various field campaigns to represent the clean and dusty conditions. The sensitivity of the TC's intensity, hydrometeor distribution, precipitation, latent heating/cooling distribution and wind fields to the number concentrations and vertical distributions of CCN, GCCN and IN are examined. Detailed microphysical budgets are derived to quantify the importance of each microphysical process on the evolution of the TC and to assess how sensitive each process is to changes in the CCN, GCCN and IN concentration and distribution.