Tropical Cyclone/Hurricane Wind

Overview

Tropical cyclones, also known as hurricanes and typhoons, cause significant destruction through high winds, storm surge and rainfall. Numerous studies link sea surface temperature to tropical cyclone development and strengthening of cyclogenesis that bring strong winds. Sea Surface Temperatures (SST) will increase under climate change. While the frequency of tropical cyclones is projected to remain relatively constant with increased atmospheric temperatures, studies suggest significant increases in the proportion of Category 4 and 5 (the most severe) cyclones across the majority of ocean basins. The rate of increase is subject to future warming scenarios. The severity of tropical cyclones is also expected to be affected, with the maximum wind intensity expected to rise with warming, providing longer and more favourable conditions for extreme weather conditions.

Baseline Hazard Data

Tropical cyclone baseline data comes from international and national government and research centre sources. The International Best Track Archive for Climate Stewardship (IBTrACS) data contains historical tropical cyclone track data, including maximum sustained wind speeds at the surface. This data is used along with ERA5 sea surface temperature data to develop a baseline tropical cyclone wind speed distribution associated with sea surface temperature. Additionally, the tropical cyclone tracks are used to develop a map of the historical frequency of tropical cyclones across the globe.

Climate Change Projections

Gridded projections of sea surface temperatures, based on GCMs from CMIP6, are used to project the change in tropical cyclone wind speed distributions. The effects of climate change on tropical cyclones captures the increase in the maximum surface wind speeds, at a rate of approximately 2.5% per degree of warming. Additionally, due to the effect of varying rates of sea surface temperature warming across the globe, the poleward movement of tropical cyclones also is captured.