Using large climate model ensembles to assess historical and future tropical cyclone activity along the Australian east coast

Abstract

Assessing regional changes in tropical cyclones (TCs) and their future impacts are challenging given the short historical record and limited sample size of these extreme events. To address this, we use large climate model ensembles to increase sample size and explore historical variability and future changes in regional TC behavior. We demonstrate this approach on basin and sub-basin scales along Australia's East Coast. Applying a TC tracking algorithm to the large ensembles, we find that the large ensembles are skillful in detecting observed historical TC trends in the Southwest Pacific (SWP) basin. Furthermore, we show that projected TC activity in the SWP basin exposes larger land areas to extreme winds and high precipitation totals. This includes southern-most portions of the SWP basin, where future TC wind speeds regularly exceed current wind loading standards. Combined, our results point to rapidly increasing risks of damaging TC winds and major TC flooding, as well as a heightened risk of water ingress through wind-driven rain.

Keywords

• Tropical cyclone impact
• Climate change
• Application of large ensembles