Tropical cyclone-permitting simulations of un-Earthlike climates

Friday, 19 December 2014: 11:20 AM
Timothy M Merlis, McGill University, Montreal, QC, Canada, Ming Zhao, NOAA Geophysical Fluid Dynamis Laboratory (GFDL), Princeton, NJ, United States and Isaac Held, Princeton Univ, Princeton, NJ, United States
Global atmospheric general circulation models with sufficiently high (about 50 km) horizontal resolution can simulate Earth-like distributions of tropical cyclones when Earth-like boundary conditions and forcing are specified. Consequently, these Earth-like simulations conform to the intuition developed over the last 50 years of observational analysis: tropical cyclones preferentially occur in low latitude, warm regions.

Here, we will present the results of high-resolution atmospheric general circulation model simulations in climatic regimes that are vastly different than Earth's by idealizing the boundary conditions and forcing. When the solar radiation and ocean heat transport are pushed to un-Earthlike distributions to probe a wider range of climatic regimes, the simulated tropical cyclone distribution can have surprising features. In particular, tropical cyclones may be more prevalent in the extratropics and may be more prevalent in the colder hemisphere of the simulated climate. The results of these simulations suggest that an understanding of the environmental parameters controlling tropical cyclones requires a broader perspective than that offered by Earth's current climate.