Sensitivity analysis for wind-driven significant wave height model in SWAN: A Sunda Strait case

Abstract

Sunda Strait is one of the most important straits in Indonesia since it connects two major islands of Indonesia as well as two oceans. Due to its high importance, it is essential to have a well understanding of significant wave height within the strait. However, there are currently no long-term significant wave data from buoy records in Indonesia. The available fine-resolution meteorology-oceanography (metocean) data around the Sunda Strait is also not as fine as other locations in the world. Therefore, hydrodynamic modelling is essential to obtain significant wave data that completely covers the strait. The aim of this study was to perform a sensitivity analysis based on Sunda Strait SWAN significant wave height model In the research, we performed a sensitivity analysis on a significant wave height SWAN model using various spatial resolution of wind forcing from the ECMWF ERA5 database. The analysis is essential to obtain the coarsest acceptable metocean data for modelling. Our result shows that higher spatial resolution of wind forcing gives better agreement with the ERA 5 wave data. For the Sunda Strait case, we recommend using no coarser than 0.5 degrees of spatial wind forcing resolution. However, we also found that the modelling result, along with models from past studies, still underestimates the reported wave height data in extreme conditions.