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RESEARCH ARTICLE

Dipole vortices in the Great Australian Bight

George R. Cresswell A D , Lars C. Lund-Hansen B and Morten Holtegaard Nielsen C
+ Author Affiliations
- Author Affiliations

A CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, Tas. 7001, Australia.

B Aquatic Biology, Bioscience, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C, Denmark.

C Arctic Technology Centre, Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800 Kgs. Lyngby, Denmark.

D Corresponding author. Email: george.cresswell@csiro.au

Marine and Freshwater Research 66(2) 135-144 https://doi.org/10.1071/MF13305
Submitted: 19 November 2013  Accepted: 3 May 2014   Published: 7 November 2014

Abstract

Shipboard measurements from late 2006 made by the Danish Galathea 3 Expedition and satellite sea surface temperature images revealed a chain of cool and warm ‘mushroom’ dipole vortices that mixed warm, salty, oxygen-poor waters on and near the continental shelf of the Great Australian Bight (GAB) with cooler, fresher, oxygen-rich waters offshore. The alternating ‘jets’ flowing into the mushrooms were directed mainly northwards and southwards and differed in temperature by only 1.5°C; however, the salinity difference was as much as 0.5, and therefore quite large. The GAB waters were slightly denser than the cooler offshore waters. The field of dipoles evolved and distorted, but appeared to drift westwards at 5 km day–1 over two weeks, and one new mushroom carried GAB water southwards at 7 km day–1. Other features encountered between Cape Leeuwin and Tasmania included the Leeuwin Current, the South Australian Current, the Flinders Current and the waters of Bass Strait.

Additional keywords: ADCP, Chl-a, CTD, NOAA, SeaWIFS.


References

Anderskouv, K., Surlyk, F., Huuse, M., Lykke-Andersen, H., Bjerager, M., and Tang, C. D. (2010). Sediment waves with a biogenic twist in Pleistocene cool water carbonates, Great Australian Bight. Marine Geology 278, 122–139.
Sediment waves with a biogenic twist in Pleistocene cool water carbonates, Great Australian Bight.Crossref | GoogleScholarGoogle Scholar |

Basson, M., Hobday, A. J., Eveson, J. P., and Patterson, T.A. (2012). ‘Spatial Interactions Among Juvenile Southern Bluefin Tuna at the Global Scale: a Large Scale Archival Tag Experiment. FRDC Project No: 2003/002.’ (CSIRO: Collingwood, VIC.)

Bye, J. A. T. (1972). Oceanic circulation south of Australia. In ‘Antarctic Oceanology II: The Australian-New Zealand Sector’, Antarctic Research Series, vol. 19. (Ed. D. E. Hayes.) pp. 95–100. (American Geophysical Union: Washington, DC.)

Cresswell, G. R., and Griffin, D. A. (2004). The Leeuwin Current, eddies and sub-Antarctic waters off south-western Australia. Marine and Freshwater Research 55, 267–276.
The Leeuwin Current, eddies and sub-Antarctic waters off south-western Australia.Crossref | GoogleScholarGoogle Scholar |

Cresswell, G. R., and Peterson, J. L. (1993). The Leeuwin Current south of Western Australia. Australian Journal of Marine and Freshwater Research 44, 285–303.

Fedorov, K. N., and Ginsburg, A. I. (1989). Mushroom-like currents (vortex dipoles): one of the most wide-spread forms of non-stationary coherent motions in the ocean. In ‘Mesoscale/Synoptic Coherent Structures in Geophysical Turbulence’. (Eds J. C. Nihoul and B. M. Jamart.) pp. 1–14. (Elsevier, Amsterdam.)

Ginsburg, A. I., and Fedorov, K. N. (1984). The evolution of mushroom-shape currents in the ocean. Akademiia Nauk SSSR. Doklady 276, 481–484.

Griffiths, R. W., and Linden, P. F. (1982). Laboratory experiments on fronts. Part I: density-driven boundary currents. Astrophysical Fluid Dynamics 19, 159–187.
Laboratory experiments on fronts. Part I: density-driven boundary currents.Crossref | GoogleScholarGoogle Scholar |

Kämpf, J., Doubell, M., Griffin, D., Matthews, R. L., and Ward, T. M. (2004). Evidence of a large seasonal coastal upwelling system along the southern shelf of Australia. Geophysical Research Letters 31, L09310.

Kalnay, E., Kanamitsu, M., Kistler, R., Collins, W., Deaven, D., Gandin, L., Iredell, M., Saha, S., White, G., Woollen, J., Zhu, Y., Chelliah, M., Ebisuzaki, W., Higgins, W., Janowiak, J., Mo, K. C., Ropelewski, C., Wang, J., Leetmaa, A., Reynolds, R., Jenne, R., and Joseph, D. (1996). The NCEP/NCAR 40-year reanalysis project. Bulletin of the American Meteorological Society 77, 437–471.
The NCEP/NCAR 40-year reanalysis project.Crossref | GoogleScholarGoogle Scholar |

McMillin, L. M., and Crosby, D. S. (1984). Theory and validation of multiple window sea surface temperature technique. Journal of Geophysical Research 89, 3655–3661.
Theory and validation of multiple window sea surface temperature technique.Crossref | GoogleScholarGoogle Scholar |

Middleton, J. F., and Bye, J. A. T. (2007). A review of the shelf–slope circulation along Australia’s southern shelves: Cape Leeuwin to Portland. Progress in Oceanography 75, 1–41.
A review of the shelf–slope circulation along Australia’s southern shelves: Cape Leeuwin to Portland.Crossref | GoogleScholarGoogle Scholar |

Nilsson, C. S., and Tildesley, P. C. (1986). Navigation and re-mapping of AVHRR imagery. In ‘1st Australian AVHRR Conference’. (Ed. A. J. Prata.) pp. 286–298. (CSIRO, Division of Groundwater Research: Perth.)

Pearce, A. F., and Griffiths, R. W. (1991). Instability and eddy pairs on the Leeuwin Current south of Australia. Deep-Sea Research 32, 1511–1534.

Petrusevics, P., Bye, J. A. T., Fahlbusch, V., Hammat, J., Tippins, D. R., and van Wijk, E. (2009). High salinity winter outflow from a mega inverse-estuary – the Great Australian Bight. Continental Shelf Research 29, 371–380.
High salinity winter outflow from a mega inverse-estuary – the Great Australian Bight.Crossref | GoogleScholarGoogle Scholar |

Richardson, L. E., Kyser, T. K., James, N. P., and Bone, Y. (2009). Analysis of hydrographic and stable isotope data to determine water masses, circulation, and mixing in the eastern Great Australian Bight. Journal of Geophysical Research 114, C10016.
Analysis of hydrographic and stable isotope data to determine water masses, circulation, and mixing in the eastern Great Australian Bight.Crossref | GoogleScholarGoogle Scholar |

Ridgway, K. R., and Condie, S. A. (2004). The 5500-km-long boundary flow off western and southern Australia. Journal of Geophysical Research 109, C04017.
The 5500-km-long boundary flow off western and southern Australia.Crossref | GoogleScholarGoogle Scholar |

Rintoul, S. R., and Sokolov, S. (2001). Baroclinic transport variability of the Antarctic Circumpolar Current south of Australia (WOCE repeat section SR3). Journal of Geophysical Research 106, 2815–2832.
Baroclinic transport variability of the Antarctic Circumpolar Current south of Australia (WOCE repeat section SR3).Crossref | GoogleScholarGoogle Scholar |

Schodlok, M. P., Tomczak, M., and White, N. (1997). Deep sections through the South Australian Basin and across the Australian‐Antarctic Discordance. Geophysical Research Letters 24, 2785–2788.
Deep sections through the South Australian Basin and across the Australian‐Antarctic Discordance.Crossref | GoogleScholarGoogle Scholar |

Sebille, E. v., England, M. H., Zika, J. D., and Sloyan, B. M. (2012). Tasman leakage in a fine-resolution ocean model. Geophysical Research Letters 39, L06601.

Strickland, J. D. H., and Parsons, T. R. (1972). ‘A Practical Handbook of Seawater Analysis.’ Bulletin Number 167. (Fisheries Research Board of Canada: Ottawa.) pp. 310.

Tomczak, M., Pender, L., and Liefrink, S. (2004). Variability of the subtropical front in the Indian Ocean south of Australia. Ocean Dynamics 54, 506–519.
Variability of the subtropical front in the Indian Ocean south of Australia.Crossref | GoogleScholarGoogle Scholar |

Truesdale, G. A., and Gameson, A. L. H. (1957). The solubility of oxygen in saline water. Journal du Conseil Permanent International pour l’Exploration de la Mer 22, 163–166.
| 1:CAS:528:DyaG1MXhtVOhs7k%3D&md5=f67a262cff62d9e11d27b098168d7a20CAS |

UNESCO (1981). ‘International Oceanographic Tables, Vol. 3.’ UNESCO Technical Papers in Marine Science, 39. (UNESCO: Paris.)