Attempt to determine some properties of the semidiurnal internal tide on the continental slope, Great Barrier Reef

Abstract

An experiment designed to determine wave parameters of the internal semidiurnal tide near 18ºS. off the Great Barrier Reef is described. It suffered from inaccuracy in position fixing, so no information on the vertical component of the phase speed was gained. Results for the horizontal component show an internal tide of wavelength 15 nautical miles and phase speed 60 cm s^-1 propagating east to south-east, at a small angle to the isobaths. A mean current of 50 cm s^-1 flowing towards the south-east along the isobaths deflects the outgoing wave; the apparent (observed) direction of propagation is eastward, the apparent phase speed is increased to 80 cm s^-1 and the apparent wavelength to 20 nautical miles.