Sensitivity analysis of WaveWatch III in Indonesian seas

Rismanto Effendi1, Arief Suryo2 and Nelly Florida Riama2, (1)Indonesian Agency for Meteorology, Climatology and Geophysics, Center for Marine Meteorology, Jakarta, Indonesia, (2)Indonesian Agency for Meteorology, Climatology and Geophysics, Center for Research and Development, Jakarta, Indonesia
For country like Indonesia, ocean dynamics play big role on weather and climate especially in coastal area. Information on ocean wave height is one of the most important variables besides the weather and wind conditions in the Maritime Meteorological Information Service contained in the Guide to Wave Analysis and Forecasting (WMO, 1998). Wave models became a major component in providing information of ocean waves due to limited observation system in the Indonesian seas. The study is using WaveWatch III, a wave model that make wave prediction using surface wind data and bathymetry. The study area covers 90° - 145° E, 15 °N - 15 °S, with time period in January 2018 in the active Asian monsoon event followed by extreme high wave events in Indonesian waters. GFS wind data is used as forcing to be run on WRF with several configurations including default settings, tropical configuration and Santos-Alamillos, et al (2013). The forecast model then validate with Meteo France – WAM, a wave re-analysis model. The result of running WaveWatch III models using several input data produce different wave height patterns. Significant wave height simulation using GFS wind input show robust result compared to other inputs, especially in the western Indian Ocean Sumatra, southern Java waters, Karimata Strait, Java Sea and the northern Pacific Ocean of Papua. All of the wind inputs running on the WaveWatch III model are not good for simulating significant wave heights in the gulf of bone. All of the simulations are using WaveWatch III default configuration. Future work could incorporate another different configuration and another input to get the best result.