Effects of tropical cyclone paths and shelf bathymetry on inducement of severe storm surges in the Gulf of Thailand

• Published in: Acta oceanologica Sinica 2020-03, Vol.39 (3), p.90-102
• Main Authors: Tomkratoke, Saifhon, Sirisup, Sirod
• Format: Article
• Language: English
• Subjects: Bathymeters; Bathymetry; Climatology; Coastal effects; Coasts; Coexistence; Cyclones; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Hurricanes; Marine & Freshwater Sciences; Mean sea level; Monsoon trough; Monsoons; Ocean models; Oceanography; Sea level; Shelving; Storm surges; Storms; Tidal waves; Tropical climate; Tropical cyclones; Troughs; Wave propagation; Wind
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-020-1558-4

The influences of tropical cyclone paths and shelf bathymetry on the inducement of extreme sea levels in a regional bay are investigated. A finite volume coastal ocean model (FVCOM) has been configured for the Gulf of Thailand-Sunda Shelf. A parametric wind model is used to drive the FVCOM. The contributions of the tropical cyclone characteristics are determined through a scenario-based study. Validation based on a historical extreme sea level event shows that the model can resolve the oscillation mechanism well. The intensification of severe storm surges in the region highly depends on four factors including phase propagation of the storm surge wave determined by the landfall position, funnel effect caused by locality of the coastline, and shelf bathymetry determined by the state of mean sea level and coastline crossing angle of the storm path. The coexistence of these factors can cause particular regions e.g. the Surat Thani Bay, inner Gulf of Thailand and Ca Mau Peninsular to experience a larger surge magnitude. These areas are found to be highly related to monsoon troughs that develop during the onset and early northeastern monsoon season (October–November).