Impacts of tropical cyclone inflow angle on ocean surface waves

The inflow angel of tropical cyclones (TC) is generally neglected in numerical studies of ocean surface waves induced by TC. In this study, the impacts of TC inflow angle on ocean surface waves were investigated using a high-resolution wave model. Six numerical experiments were conducted to examine, in detail, the effects of inflow angle on mean wave parameters and the spectrum of wage directions. A comparison of the waves simulated in these experiments shows that inflow angle significantly modifies TC-induced ocean surface waves. As the inflow angle increases, the asymmetric axis of the significant wave height (SWII) field shifts 30 degrees clockwise, and the maximum SWH moves from the front-right to the rear-right quadrant. Inflow angle also affects other mean wave parameters, especially in the rear-left quadrant, such as the means wave direction, the mean wavelength, and the peak direction. Inflow angle is a key factor in the wave models for the reproduction of double-speak or multi-peak patterns in the spectrum of wave directions. Sensitivity experiments also show that the simulation with a 40 degrees inflow angle is the closest to that of the NOAA statistical SLOSH inflow angle. This suggests that 40 degrees can be used as the inflow angle in future TC-induced ocean surface wave simulations when SLOSH or observed inflow angles are not available.