Near-Resonances of Superinertial and Tidal Fluctuations at Islands

Abstract A linear numerical model of an island or a tall seamount is used to explore superinertial leaky resonances forced by ambient vertically and horizontally uniform current fluctuations. The assumes circularly symmetric topography (including shallow reef) allows realistic stratification bottom friction. As long as there substantial stratification, number are found, when the island’s flanks narrow relative internal Rossby radius, some near-resonant modes resemble Kelvin waves. Other “resonances” higher radial mode gravity waves explored Chambers. near-resonances amplify cross-reef velocities that help fuel biological activity. Results for cases with central replaced lagoon do not differ greatly from case which has land at center. aside, insight provided on question offshore boundary conditions nearly trapped along straight coast.