Observed Near-Inertial Waves in the Northern South China Sea

Characteristics of near-inertial waves (NIWs) induced by the tropical storm Noul in South China Sea are analyzed based on situ observations, remote sensing, and analysis data. Remote sensing sea level anomaly data suggests that NIWs were influenced a southwestward moving anticyclonic eddy. The had comparable spectral density with internal tides, horizontal velocity 0.14–0.21 m/s. kinetic energy maximum value 7.5 J/m3 propagated downward vertical group speed 10 m/day. Downward propagation concentrated smaller wavenumber bands overwhelmed upward energy. e-folding time ranged from 4 to 11 days, larger resulted mesoscale eddies negative vorticity. Modified background relative vorticity, observed both red-shifted blue-shifted frequencies. propagating phase speeds wavelengths than NIWs. There was transfer field 8.5 × 10−9 m2 s−3 when total shear vorticity geostrophic currents commensurate. Our results suggest significant factor influencing generation Sea.