...
By forcing GSTM with wind and atmospheric pressure from climate reanalysis, GSTM can be used to simulate historical water levels. The first reanalysis dataset of extreme sea levels was the Global Tide and Surge Reanalysis (GTSR) dataset, which was published by Muis et al. in 2016. This dataset was based on surge simulations of GTSMv2.0 forced with ERA-Interim, combined with tide simulations of the FES2012 model. An updated reanalysis dataset was published based on GTSMv3.0 forced with ERA5 (Muis et al., 2020). The timeseries can be used to analyse individual historical events, but also to investigate trends and variability. The timeseries are also used to derive statistics on water levels, such as percentiles and return periods. The return periods form the basis of many large-scale assessments of coastal flood hazard and risk, for example, for the Aqueduct Flood Risk Analyser of the World Resources Institute. Dullaart et al. (2021) improved the return periods for tropical regions by combining the ERA5 reanalysis with thousands of synthetic tropical cyclones. The ERA5 reanalysis is also used to produce a high-resolution global flood extent maps due to coastal flooding at the Microsoft Planetary Computer, both for historical events as well as for various return periods considering sea level rise in present and future conditions.
Figure 3: Maximum modelled surge height for tropical cyclone Florence (panel A), extra-tropical storm Ophelia (panel B), and tropical cyclone Irma (panel C). Storm surges were generated forcing GTSMv3.0 with ERA5. Source: Dullaart et al. (2020).
Climate change projections
...