Generating Synthetic Tropical Cyclone Databases for Input to Modeling of Extreme Winds, Waves, and Storm Surges

The attack of a severe tropical cyclone at any location is a rare event; therefore, a long data record is necessary in order to determine the characteristics of the population of storms that can affect a location. Unfortunately, reliable and complete data of tropical cyclone tracks and central pressures are not nearly long enough to define the severe end of the distributions. To mitigate this problem of the lack of data in the two Australian tropical cyclone regions a state-of-the-art modeling system has been developed and deployed in three projects, two in the Coral Sea (Hardy et al., 2003, 2004) and one in the Northwestern Australia waters. The Coral Sea studies produced a set of 3,000 years of synthetic tropical cyclones and then simulated the winds, waves, and storm tides. Three climate change scenarios were also modeled. The Northwestern study was much more ambitious, modeling 100,000 years of tropical cyclones to obtain robust measures of the 100-10,000 year return periods of wind and wave conditions. The modeling system required development and/or adaptation of a series of models: (a) synthetic tropical cyclone model, (b) parametric wind field model, (c) wave model, and (d) storm surge and current model. This modeling technique could be applied to any tropical cyclone region to provide input to wind, wave, storm surge, erosion, rainfall, and flood routing models.