Projected changes in cyclonic wind hazard in the Australian region

The cyclonic wind hazard over the Australian region is determined using synthetic tropical cyclone event sets derived from general circulation models (GCMs) to provide guidance on the potential impacts of climate change. Cyclonic wind hazard (defined as the return period wind speed) is influenced by the frequency, intensity and spatial distribution of tropical cyclones, all of which may change under future climate regimes due to influences such as warmer sea surface temperatures and changes in the global circulation. Cyclonic wind hazard is evaluated using a statistical-parametric model of tropical cyclones – the Tropical Cyclone Risk Model (TCRM) – which can be used to simulate many thousands of years of cyclone activity. TCRM is used to generate synthetic tracks which are statistically similar to the input event set – either an historical record or other synthetic event set. After applying a parametric wind field to the simulated tracks, we use the aggregated wind fields to evaluate the return period wind speeds for three IPCC AR4 scenarios, and make comparisons to the corresponding average recurrence interval wind speed estimates for current climate simulations. Results from the analysis of two GCMs are presented and contrasted with hazard estimates based on the historical record of tropical cyclones in the Australian region.