How and Why Does Tropical Cyclone Precipitation Respond to Climate Change?

Tropical cyclone (TC) precipitation can create dangerous hazards and cause millions of dollars in damages. While previous literature agrees that future TC precipitation will increase due to rising global temperatures, the estimates of how much it will increase vary, ranging from around 3 to 20% per °C of warming, or three times the Clausius-Clapeyron scaling (about 7% per °C). In this talk, various methodologies and datasets are utilized to disentangle the interwoven factors that impact the response of TC precipitation to climate warming, including TC intensity, outer size, landfall frequency, and increases in atmospheric moisture. Results are first presented for future model projections of the North Atlantic and eastern United States using variable-resolution CAM5 and then generalized globally using idealized radiative convective equilibrium CAM5 simulations. TCs and their precipitation in the idealized simulations are compared to those in more realistic CAM5 simulations and satellite observations, and all of these datasets are used to untangle the relationship between TC precipitation and sea surface temperature (SST) on relatively short timescales (known as apparent scaling) and on long-term climate timescales (known as climate scaling).