Estimating Changes in North Atlantic Tropical Cyclones Due to Climate Change
Simulated tropical cyclones in the North Atlantic are compared between a historical climate configuration and two Representative Concentration Pathway projections in the Community Atmosphere Model version 5 to estimate the future impacts of climate change on tropical cyclones.
Results suggest that while the number of tropical cyclones that hit the eastern United States will decrease in the future, the amount of rainfall produced per hour of storm impact will increase.
Historical climate simulations (1985-2014) and two Representative Concentration Pathway projections (RCP4.5 and RCP8.5 for 2070-2100) are completed using a variable-resolution configuration of the Community Atmosphere Model version 5 with 28 km grid spacing over the whole North Atlantic basin and 111 km grid spacing over the rest of the global domain. Results from these simulations, including tropical cyclone (TC) counts, intensity, outer size, and overland precipitation, are compared to estimate the impacts of climate change on North Atlantic TCs. North Atlantic basin-wide TC counts and eastern US landfalling TC counts decreases in the RCP simulations compared to the historical simulation. Consequently, the annual mean TC precipitation over the eastern US decreases as well over most of the coastal states. However, the rainfall per hour of storm impact is greater in the RCP simulations compared to the historical simulation, especially over regions of the Gulf Coast. Additionally, the probability of more extreme precipitation rates within TCs is higher in the RCP simulations compared to the historical simulations