ABSTRACT
Low-frequency (LF) motions is the motions which have a period greater than a few days, and which are not driven by the astronomical tides. They are calculated numerically from time series of wind, currents, and sea-level data by filtering out the tidal components. The propagation speed of the LF sea-level disturbances was calculated from the difference between times of arrival for disturbances reaching pairs of locations. Data from a cross-shelf transect of current metres revealed that the circulation is weak and variable. The circulation is controlled by several factors operating simultaneously: the eastward Coral Sea Coastal Current in the northwest Coral Sea; the wind; the river runoff which results in a strong salinity stratification of the Gulf; and the current through the Great North East Channel.
