The Verification Significant Wave Height Technique in Indonesian Waters and Analysis of Low Air Pressure

Abstract

A limited number of marine meteorological instruments for making observations in Indonesian waters are problems in verifying the BMKG-OFS model. The satellite altimetry was selected as a verification tool due to its wide measurement range. The verification was carried out by adjusting the coordinates, time, and grid of SWH obtained and orbit of the satellite path from the satellite altimetry to the model and overlaying the models' results as a pattern analysis in July 2018 -June 2019. The next step was a statistical analysis to determine the performance of the model. The analysis obtained 43% maximum SWH formed due to the low-pressure centers in the Pacific Ocean. The remaining spreads across the South China Sea, Indian Ocean, Andaman Sea and the Gulf of Australia. This study revealed that the SWH values from satellites were higher than the model. On every three hourly and monthly bases, the SWH of the bias, RMSE, and correlation coefficient were equivalent. The lowest bias of 0.26 occurred at 9.00 UTC, the lowest RMSE of 0.48 occurred at 21:00 UTC, and the maximum correlation coefficient of 0.82 occurred at 18:00 UTC. Whereas on a monthly scale, the lowest bias and RMSE, and the maximum correlation coefficient occurred in November. Based on these results, the BMKG-OFS model can be used to predict SWH in Indonesian waters. Besides, this verification technique can be an alternative as a new tool to verify maritime weather in the operational of BMKG.