Impacts of Sea Salt on an Idealized Tropical Cyclone Simulation: Description of a Bulk Sea Salt Aerosol Microphysics Parameterization and Case Study

This study describes a new bulk parameterization for sea salt aerosol (SSA) microphysics and investigates the impacts of SSA on an idealized tropical cyclone (TC) through numerical experiments. Results indicate that consideration of SSA microphysics enhances total precipitation and shifts its timing earlier, with opposite effects during the rapid intensification (RI) and mature (Mt) stages. During RI, SSA increases the maximum 10-m wind speed, strengthens eyewall updrafts, condensation, and cloud/rainwater content, while cooling mid-lower layers. In the Mt stage, SSA slightly reduces the wind speed, cools the warm core, elevates the latent heat release center to ~500 m above the surface, and weakens the eyewall but enhances the outer rainband precipitation process. The findings reveal that SSA processes significantly strengthen TCs only during the RI stage, contrasting with previous studies showing continuous TC enhancement by SSA.