Numerical modeling of solitary wave interactions around an idealized conical island
Image credit: S.TanAbstract
Tidal currents in the Luzon Strait generate some of the largest internal waves documented in the global oceans. These waves steepen and disperse into solitary waves as they propagate westward across the Southern China Sea, striking the Dongsha Atoll from the east, and eventually shoaling on the Chinese continental slope and shelf. The steep topography of the Dongsha Atoll causes the solitary waves to reflect, refract, and shoal, which redirects and redistributes wave energy throughout the wave spectrum and/or transforms it into potential energy via mixing. Wave-wave interactions and wave-island interactions can redistribute wave momentum and induce residual azimuthal flows due to the effects of the Earth’s rotation. Despite extensive studies on solitary wave dynamics, our understanding of the energy and momentum transfer between incoming solitary waves, reflected and refracted waves, breaking waves, and wave-driven flows, remains incomplete. In this study, we aim to address this gap by simulating the exact solitary wave solution of the Dubreil-Jacotin-Long (DJL) equation using the SUNTANS, a highly accurate nonlinear, non-hydrostatic numerical model. Specifically, we investigate the propagation of the solitary wave from one boundary of the model domain into a conical island, and analyze the energy and momentum budgets in front of and behind the island, as well as along and across its slope. Through this analysis, we hope to gain new insights into the complex behavior of waves interacting with islands.
