FastFind »   Lastname: doi:10.1029/ Year: Advanced Search  

AGU: Journal of Geophysical Research, Oceans

 

Keywords

  • upwelling
  • Australia
  • Great Australian Bight

Index Terms

  • Oceanography: General: Upwelling and convergences
  • Oceanography: General: Descriptive and regional oceanography
  • Oceanography: Physical: Nearshore processes
  • Oceanography: General: Water masses
Abstract
Cited By (14)
 

Abstract

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, C08007, 13 PP., 2006
doi:10.1029/2004JC002699

Water mass analysis and alongshore variation in upwelling intensity in the eastern Great Australian Bight

Sam McClatchie

South Australian Aquatic Sciences Centre, SARDI Aquatic Sciences, Henley Beach, South Australia, Australia

John F. Middleton

School of Mathematics, University of New South Wales, Sydney, New South Wales, Australia

Tim M. Ward

South Australian Aquatic Sciences Centre, SARDI Aquatic Sciences, Henley Beach, South Australia, Australia

A study of climatological and conductivity-temperature-depth (CTD) data for 2004 is made to provide a conceptual model of upwelling for the eastern region of the Great Australian Bight. In particular, the data and other studies provide strong evidence that shelf break upwelling is confined to the southwest Kangaroo Island region and does not occur farther to the west off the Eyre Peninsula. Rather, the upwelled water is likely to remain in a Kangaroo Island “pool” until subsequent upwelling events draw the water to the shallower and surface coastal regions of the eastern Bight. In this manner the surface upwelling apparent off the Bonney Coast, Kangaroo Island, and the eastern Great Australian Bight (GAB) can appear to be simultaneous. Moreover, it appears likely that the water within the Kangaroo Island pool remains nutrient rich. Support for this model comes from CTD sections collected in 2004 that show that the upwelled signal (cool, <17°C; fresher, <35.6; dense, σ t > 26 kg m−3) diminishes in width and intensity with increasing distance from Kangaroo Island. The pattern of fluorescence is similar to that for temperature in the upwelled plume and indicates that the Kangaroo Island pool remains nutrient rich. Relatively low oxygen concentrations may indicate a previous bloom. The warmest water is found near the shelf break along with very low values of fluorescence and relatively higher levels of oxygen suggesting nutrient-limited growth of phytoplankton. These data also support the notion that the upwelled nutrient-rich water is supplied from the Kangaroo Island pool and not by shelf break upwelling in the eastern GAB. Anomalously salty and fresh water is identified as resulting from evaporation in coastal bays and groundwater aquifer discharge.

Received 3 September 2004; accepted 6 April 2006; published 5 August 2006.

Citation: McClatchie, S., J. F. Middleton, and T. M. Ward (2006), Water mass analysis and alongshore variation in upwelling intensity in the eastern Great Australian Bight, J. Geophys. Res., 111, C08007, doi:10.1029/2004JC002699.

Cited By

Please wait one moment ...