Global and Basin Tropical Cyclone Frequency Indices

Dynamical climate models, although sophisticated and capable of running at very high resolutions are still too expensive to be run at these resolutions for very long simulations. This places a limitation on the direct use of dynamical models for assessing tropical cyclone changes in both the current climate as well as under future climate change scenarios. Here we describe the use of statistical methods to supplement the dynamical models in assessing cyclone climatologies.

Specifically, we investigate the development of global and basin specific tropical cyclone frequency indices through statistical downscaling methods. The basis of this work is the Genesis Potential Index (GPI) developed by Emanuel and Nolan, and the North Atlantic Cyclone Genesis Index (CGI, Bruyere et al., submitted). As different environmental conditions are responsible for cyclone genesis in different basins, our approach is not strictly the development of a single global index that can be applied to different basins, but rather the development of basin specific indices.