This paper investigates the performance of the spectral wave model WAVEWATCH III (WW3, v6.07) during the Very Severe Cyclonic Storm (VSCS) Okchi that originated in Bay of Bengal (BoB) in 2017 and recurved to Arabian sea (ARB). The default source term packages, ST2/ST3/ST4 and ST6 of the spectral wave model are tested in deep and finite water depths. The simulated results are validated with buoy measurements for significant wave height (Hs), mean time period (TM02) and mean wave direction. Statistical error estimates are used for validation. Overall, ST2 performs poorer than other source term packages in the wave model. Considering finite depths, the performance of ST6 is much better than ST2/3/4.
Tropical cyclones (TCs) in Bay of Bengal (BoB) cause heavy loss to human life and nearshore structures owing to their increasing frequency and higher intensities (Uma and Sannasiraj, 2023). Presently, the third generation wave models such as WAVEWATCH III (WW3, Tolman et al., 2019), SWAN (Booji et al., 1999), WAM (WAMDIGroup, 1988) and TOMAWAC (Benoit et al., 1996) are gaining momentum in the area of wind-wave modeling. These spectral wave models solve the action balance equation with RHS involving source terms responsible for wave formation and the LHS being the propagation terms. Generally, wind input source term, white capping dissipation term, nonlinear wave-wave interaction source term play a significant role in deep water depth, depth induced breaking and bottom friction comes to role in finite depths. In addition to these finite depth source term there are terms meant for vegetation, triad interactions etc that can be considered depending upon the purpose of the study. The nonlinear wave-wave interaction source term plays a vital role in deep water and the other two deep water source terms such as wind input and dissipation source term are tuned in accordance with it to maintain source term balance. In this relevance there are several input-dissipation packages (modern) referred to as source term (ST) packages and are available in WW3.