Energetics of Internal Solitary Waves Interacting With a Conical Island

Abstract The interaction of internal solitary waves (ISWs) with sloping topography plays a critical role in ocean mixing and energy dissipation. We use idealized simulations of an ISW shoaling on a conical island to analyze spatial energy pathways, with parameters based on observations at Dongsha Atoll in the South China Sea, which is located in the path of some of the world's largest ISWs. Results show that energy dissipation is highly heterogeneous, concentrated in shallow regions where the wave is normally incident and along the island flanks. Unlike two‐dimensional slopes, three‐dimensional topography enables partial conversion of baroclinic to barotropic kinetic energy on the wave‐facing slope, driven by a longshore barotropic pressure gradient induced by shoaling. This conversion accounts for 20% of the total baroclinic energy divergence over the island. The resulting barotropic currents form recirculation cells that advect around the island and eventually transfer energy back into baroclinic kinetic energy along deeper flanks and the lee slope before dissipating. Earth's rotation further modulates the distribution of wave energy and barotropic flow patterns. Understanding these spatially variable energetics and wave‐driven barotropic currents is essential for predicting energy pathways and transport mechanisms that influence cross‐ and along‐shore exchange of nutrients and heat, with implications for sensitive island ecosystems.