An array of 15 Aanderaa current meters (C), 4 Aanderaa water level recorders (WLR) and 4 Sea Data temperature-depth recorders (TDR) were deployed in the central Great Barrier Reef between January and August 1983.The array was deployed to cover as much of the extent of the central zone (approximately 350km between 17°S and 20°S) as was necessary to gain a general picture of the space-time extent of intrusions. The array was configured to provide a longshore line of thermistors and water level recorders, interspersed with current meters. This longshore line was closed at the north and south by cross-shelf transects of current meters and was bisected by a transect of current meters, water level recorders and termistors in Palm Passage. Instruments were concentrated in the Passage to facilitate the interpretation of data from concurrent cross-shelf transect cruises, sampling chemical and biological water properties. Current meters were placed 5 to 10 m above the bottom, except at moorings 6 and 8, which also carried a mid-depth current meter to allow estimation of vertical shear. Temperature-depth recorders and water level recorders were placed on either very short bottom moorings or in the protection of reefs or islands. Meteorological data were obtained at half-hourly intervals from a remote weather station located at Rib Reef.
This study was initiated to investigate the horizontal extent and coherence of upwelling related intrusions of Coral Sea water into the shelf sea of the central Great Barrier Reef.
A concurrent time series of data was collected from hydrographic stations, located at the centre of the instrument array, along a transect through Palm Passage, to enable mapping of the vertical structure during the progress of individual intrusion events. A description of the hydrographic sampling is not included in this record.
