Parameter Sensitivity of Tropical Cyclones in NASA-GISS ModelE3

Tropical cyclones are among the most destructive and deadly natural hazards. However, global climate models still have considerable issues in predicting their frequency and distribution and even more so about how these will change under global warming. Many modeling centers have pushed for higher resolution in an effort to better simulate tropical cyclones, but with that transition comes a need to better understand how model parameterizations affect tropical cyclone climatologies. We present results from a new version of the NASA Goddard Institute for Space Studies (GISS) ModelE3 global climate model which has been configured at a hierarchy of horizontal resolutions including 2 x 2.5 degrees and 0.5 degrees (C180). While the model is still undergoing testing, it has already shown vast improvements over earlier generations of NASA-GISS GCMs as well as earlier versions of the same ModelE3. It more accurately produces stronger and more compact tropical cyclones as well as improved global, spatial and temporal distributions of tropical cyclones. However, like many models of this resolution, ModelE3 has similar issues in not being able to simulate the most intense tropical cyclones. We present results from several parameter sensitivity experiments which focus on this improvement in tropical cyclone counts, distributions, and structure alongside common cyclogenetic measures of the mean tropical climate.