High Resolution Winds Model

The impact of winds associated with tropical cyclones is being modeled based on a downscaling of ERA-5 winds. The downscaling has been performed by Climate Scale, an experienced company of atmospheric modeling. The wind resolution at the island scale is up to 100m in Savaii, Upolu and Tongatapu based on the Weather Research and Forecasting model (WRF). The selection of the cases to simulate are accounting for all the historical cyclones that have occurred in the South Pacific since 1979 from IBTrACS database, no matter the location, with the aim of populating the number of TCs hitting Samoa and Tonga. Then for the downscaling, we have performed a spatial translation of the historical tracks to cross the islands.

The selection of the cases is explained below:

Then, all these selected TCs are spatially translated to the islands, and WRF model is run, which is also explained below: