Convection Parameterization Sensitivity and Hurricane Statistics over the Inter-Americas region

Tropical cyclones (TCs) affect the Caribbean and East Pacific basins, causing large economic damages and loss of human life. In the last two decades, a number of studies have analyzed their frequency, duration and intensity changes under a future warming climate forced by greenhouse gases or Representative Concentration Pathway (RCP) using global and regional climate model simulations (RCMs). The main advantage of using RCMs is to simulate TCs over specific regions using spatial horizontal resolutions higher than that typically used in global climate models. An important issue to solve is to have model physical parameterizations that better represent the physical processes in TCs. For that reason, it is very important to analyze how they represent past climatic conditions, to have confidence in their performance simulating future conditions. In this study, we conduct sensitivity tests based on four different convective parameterizations in high-resolution regional climate simulations of tropical cyclones over the eastern Pacific and the Caribbean basins during the period 1980-2004. The simulations are performed using the Regional Climate Model (RegCM4) in a 25 km x 25 km grid using the Emanuel, Grell, Tiedke, and Kain-Fritsch schemes over land and the Emanuel scheme over the oceans (EmEm, GrEm, TkEm, KFEm, respectively). We examined the sensitivity of the density, duration and intensity of TCs and offer hypotheses of the direct impact of inland convection treatment (e.g., on the roles of intensity-diurnal cycle of precipitation and potential vorticity generation/conversion) in such TCs statistics.