Tropical cyclone storm surge is a change in the water level compared to the standard water level, induced by tropical cyclones/hurricanes/typhoons. Tropical cyclone storm surge can be one of the most damaging aspects of tropical cyclones, especially in regions where buildings are designed to withstand tropical cyclone wind speeds. Additionally, storm surges can cause significant loss of life. Storm surge itself is separate from the additional, compounding effects of storm tide (storm surge + tide) and the impact of waves.
Two main effects contribute to storm surge. The first, is the development of a fetch - an area where winds are relatively constant in both direction and speed, which pushes water in one direction. The fetch causes a rise in sea level due to forcing water toward the shore. The second effect is that of pressure - tropical cyclones are deep low-pressure systems. ‘Barometric uplift’, or the inverse barometer effect approximately causes a 0.01 m rise in sea level for every 1 hPa drop in pressure. The Tropical Cyclone Storm Surge (TCSS) developed for the Climate Risk Engines aims to capture both of these effects by utilising the results of the tropical cyclone wind model.
As TCSS is a rise in local sea heights, the future change in sea level will also affect future TCSS heights. This is in addition to changes in TCSS due to increasing tropical cyclone intensity alone