Current-Shelf interactions during the Australian Coastal experiment

Abstract

Current-meter records from the Australian Coastal Experiment are examined. In addition to the long, coastal-trapped waves with λ > 800 km that this experiment was specifically designed to investigate, the current records also show distinct event-like bursts of wave activity. These events appear to be related to offshore current structures and are observed over the slope as low-frequency current oscillations with periods of 3-5 days and lasting for 3-4 cycles.

It is postulated that these topographic waves are generated by the interaction of the East Australian Current and associated eddies with the sloping topography of the East Australian shelf region. Outside the intensely nonlinear region where these waves are initially generated, they take on the appearance of a set of dispersing internal shelf waves.