Impacts of Climate Change on Tropical Cyclone Tracks

To help understand the potential impacts of rising CO₂ on North Atlantic tropical cyclone tracks, changes in track density associated with variations in the large-scale steering flow and genesis location are examined. The tracks are simulated using a beta and advection model and the large-scale steering flow simulated by 17 coupled ocean-atmosphere models for the IPCC AR4 A1B scenario. Tracks are initialized at the historical genesis location for all recorded storms in the North Atlantic basin for the period 1950-2010 and then weighted by the genesis potential index. The ensemble mean difference in track density between the current and future climate results in modest changes associated with variations in the large-scale circulation and genesis potential index. Both the changes in large-scale steering flow and the shift in genesis potential contribute to a modest decrease in the projected track density for the Southern Gulf of Mexico and Western Caribbean of ~2-3 storms per decade. Analysis of the changes in tropical cyclone tracks in other ocean basins is underway and will be presented at the conference.