Abstract
This article presents an investigation of wave fields during the approach of typhoon LINDA in 1997 in the Gulf of Thailand. Two modeling approaches are studied: The hard computing approach by the WAM cycle 4 model was used first to simulate wave heights and periods distribution covering the domain 95°E to 105°E and 5°N to 15°N. Then, the soft computing approach by the GRNN model was developed to predict the wave characteristics for lead times of 3, 6, 9, 12, and 24 h. The input wind data were obtained from NOGAPS model archives with 1° resolution and are linearly interpolated to specify wind components at each grid point. The WAM model underestimated the wave height as much as 20%. The root mean square errors (RMSEs) and the mean absolute deviations (MADs) are 0.18–0.26 m and 0.13–0.18 m, respectively. The GRNN showed better forecasting results than the WAM model (RMSE<0.15 m and MAD<0.10 m). The maximum wave height simulated by the GRNN model during the typhoon Linda 1997 event was found to be 4.0 m. This indicates that for short-term prediction within 24 h, the data-driven model such as the GRNN should be viewed as a strong alternative in operational forecasting.
Acknowledgements
The author, W.K., is particularly indebted to the Royal Golden Jubilee Ph.D. Program for the financial support (contract numbers PHD/0100/2544) which enabled to undertake this study. Authors would like to thank GISTDA (Geo-Informatics and Space Technology Development Agency) for supplying them with a copy of the WAM model source code and data files. Authors also thank Unocal Co. (Thailand) for providing the data.