Subinertial Oscillations on the Amundsen Sea Shelf, Antarctica

Abstract

Mooring data from the western flank of Dotson Trough, Amundsen Sea shelf region, show the presence of barotropic oscillations with a period of 40-80 hours. The oscillations are visible in velocity, temperature, salinity and pressure, and are comparable to tides in magnitude. The period of the oscillations corresponds to topographic Rossby waves of low group velocity and wavelength about 40 km, i.e. the half-width of the channel. It is suggested that these resonant topographic Rossby waves cause the observed peak in the wave spectra. The observations show that sparse CTD data from this region should be treated with caution and need to be complemented with moorings or yo-yo stations in order to give a representative picture for the hydrography.