• Atkinson, A., , M. J. Whitehouse, , J. Priddle, , G. C. Cripps, , P. Ward, , and M. A. Brandon, 2001: South Georgia, Antarctica: A productive, cold water, pelagic ecosystem. Mar. Ecol. Prog. Ser., 216 , 279308.

    • Search Google Scholar
    • Export Citation
  • Bauer, S. A., , A. Griffa, , M. Swenson, , A. Mariano, , and K. Owens, 1998: Eddy-mean flow decomposition and eddy diffusivity estimates in the tropical Pacific Ocean. 1. Methodology. J. Geophys. Res., 103 , 30 85530 871.

    • Search Google Scholar
    • Export Citation
  • Beckmann, A., , and R. Timmermann, 2001: Circumpolar influences on the Weddell Sea: Indication of an Antarctic circumpolar coastal wave. J. Climate, 14 , 37853792.

    • Search Google Scholar
    • Export Citation
  • Boyd, P. W., and Coauthors, 2000: A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization. Nature, 407 , 695702.

    • Search Google Scholar
    • Export Citation
  • Chelton, D. B., , R. A. deSzoeke, , M. G. Schlax, , K. El Naggar, , and N. Siwertz, 1998: Geographical variability of the first-baroclinic Rossby radius of deformation. J. Phys. Oceanogr., 28 , 433460.

    • Search Google Scholar
    • Export Citation
  • Davis, R. E., 1991: Observing the general circulation with floats. Deep-Sea Res., 38 , (suppl.). S531S571.

  • Davis, R. E., 1998: Preliminary results from directly measuring mid-depth circulation in the Tropical and South Pacific. J. Geophys. Res., 103 , 24 61924 639.

    • Search Google Scholar
    • Export Citation
  • Fahrbach, E., , G. Rohardt, , and G. Krause, 1992: The Antarctic coastal current in the southeastern Weddell Sea. Polar Biol., 12 , 171182.

    • Search Google Scholar
    • Export Citation
  • Fahrbach, E., , G. Rohardt, , M. Schroder, , and V. Strass, 1994: Transport and structure of the Weddell Gyre. Ann. Geophys., 12 , 840855.

  • Fahrbach, E., , S. Harms, , G. Rohardt, , M. Schroder, , and R. A. Woodgate, 2001: Flow of bottom water in the northwestern Weddell Sea. J. Geophys. Res., 106 , 27612778.

    • Search Google Scholar
    • Export Citation
  • Falco, P., , A. Griffa, , P-M. Poulain, , and E. Zambianchi, 2000: Transport properties in the Adriatic Sea as deduced from drifter data. J. Phys. Oceanogr., 30 , 20552071.

    • Search Google Scholar
    • Export Citation
  • Falkowski, P. G., , R. T. Barber, , and V. Smetacek, 1998: Biogeochemical controls and feedbacks on ocean primary production. Science, 281 , 200206.

    • Search Google Scholar
    • Export Citation
  • Fitzwater, S. E., , K. S. Johnson, , R. M. Gordon, , K. H. Coale, , and W. O. Smith, 2000: Trace metal concentrations in the Ross Sea and their relationship with nutrients and phytoplankton growth. Deep-Sea Res. II, 47 , 31593179.

    • Search Google Scholar
    • Export Citation
  • Gill, A. E., 1973: Circulation and bottom water production in the Weddell Sea. Deep-Sea Res., 20 , 111140.

  • Hansen, D. V., , and P-M. Poulain, 1996: Quality control and interpolations of WOCE–TOGA drifter data. J. Atmos. Oceanic Technol., 13 , 900909.

    • Search Google Scholar
    • Export Citation
  • Heywood, K. J., , R. A. Locarnini, , R. D. Frew, , P. F. Dennis, , and B. A. King, 1998: Transport and water masses of the Antarctic Slope Front system in the eastern Weddell Sea. Ocean, Ice, and Atmosphere: Interactions at the Antarctic Continental Margin, S. S. Jacobs and R. F. Weiss, Eds., Antarctic Research Series, Vol. 75, Amer. Geophys. Union, 203–214.

    • Search Google Scholar
    • Export Citation
  • Heywood, K. J., , A. C. Naveira Garabato, , D. P. Stevens, , and R. D. Muench, 2004: On the fate of the Antarctic Slope Front and the origin of the Weddell Front. J. Geophys. Res., 109 , C06021. doi:10.1029/2003JC002053.

    • Search Google Scholar
    • Export Citation
  • Heywood, R. B., , and J. Priddle, 1987: Retention of phytoplankton by an eddy. Cont. Shelf Res., 7 , 937955.

  • Hofmann, E. E., , J. M. Klinck, , R. A. Locarnini, , B. A. Fach, , and E. J. Murphy, 1998: Krill transport in the Scotia Sea and environs. Antarct. Sci., 10 , 406415.

    • Search Google Scholar
    • Export Citation
  • Holloway, G., 1992: Representing topographic stress for large-scale ocean models. J. Phys. Oceanogr., 22 , 10331046.

  • Holm-Hansen, O., and Coauthors, 2004a: Factors influencing the distribution, biomass, and productivity of phytoplankton in the Scotia Sea and adjoining waters. Deep-Sea Res. II, 51 , 13331350.

    • Search Google Scholar
    • Export Citation
  • Holm-Hansen, O., and Coauthors, 2004b: Temporal and spatial distribution of chlorophyll-a in surface waters of the Scotia Sea as determined by both shipboard measurements and satellite data. Deep-Sea Res. II, 51 , 13231331.

    • Search Google Scholar
    • Export Citation
  • Jacobs, S. S., 1986: The Antarctic Slope Front. Antarct. J. U.S., 21 , 123124.

  • Jacobs, S. S., 1991: On the nature of the Antarctic Slope Front. Mar. Chem., 35 , 924.

  • Korb, R. E., , M. J. Whitehouse, , and P. Ward, 2004: SeaWIFS in the southern ocean: Spatial and temporal variability in phytoplankton biomass around South Georgia. Deep-Sea Res. II, 51 , 99116.

    • Search Google Scholar
    • Export Citation
  • Kottmeier, C., , J. Olf, , W. Frieden, , and R. Rainer, 1992: Wind forcing and ice motion in the Weddell Sea. J. Geophys. Res., 97 , 20 37320 383.

    • Search Google Scholar
    • Export Citation
  • LaCasce, J. H., 2000: Floats and f /h. J. Mar. Res., 58 , 6195.

  • LaCasce, J. H., , and K. Speer, 1999: Lagrangian statistics in unforced barotropic flows. J. Mar. Res., 57 , 245275.

  • Martin, J. H., , R. M. Gordon, , and S. E. Fitzwater, 1990: Iron in Antarctic waters. Nature, 345 , 156158.

  • McWilliams, J. C., , and J. M. Restrepo, 1999: The wave-driven ocean circulation. J. Phys. Oceanogr., 29 , 25232540.

  • Muench, R. D., , and A. L. Gordon, 1995: Circulation and transport of water along the western Weddell Sea margin. J. Geophys. Res., 100 , 18 50318 515.

    • Search Google Scholar
    • Export Citation
  • Murphy, E. J., , S. E. Thorpe, , J. L. Watkins, , and R. Hewitt, 2004: Modeling the transport pathways in the Scotia Sea: Spatial and environmental connections generating the seasonal distribution of krill. Deep-Sea Res. II, 51 , 14351456.

    • Search Google Scholar
    • Export Citation
  • Niiler, P. P., , A. S. Sybrandy, , K. Bi, , P-M. Poulain, , and D. Bitterman, 1995: Measurements of the water-following capability of holey-sock and TRISTAR drifters. Deep-Sea Res. I, 42 , 19511964.

    • Search Google Scholar
    • Export Citation
  • Niiler, P. P., , N. A. Maximenko, , and J. C. McWilliams, 2003: Dynamically balanced absolute sea level of the global ocean derived from near-surface velocity observations. Geophys. Res. Lett., 30 , 2164. doi:10.1029/2003GL018628.

    • Search Google Scholar
    • Export Citation
  • Olson, D. B., , V. H. Kourafalou, , W. E. Johns, , G. Samuels, , and M. Veneziani, 2007: Aegean surface circulation from a satellite-tracked drifter array. J. Phys. Oceanogr., 37 , 18981917.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., , W. D. Nowlin, , and T. Whitworth, 1993: On the circulation and stratification of the Weddell Gyre. Deep-Sea Res., 40 , 169203.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., , G. C. Johnson, , and J. L. Bullister, 1999: Circulation, mixing and production of Antarctic Bottom Water. Prog. Oceanogr., 43 , 55109.

    • Search Google Scholar
    • Export Citation
  • Padman, L., , H. A. Ricker, , R. Coleman, , S. Howard, , and S. Erofeeva, 2002: A new tidal model from the Antarctic ice shelves and seas. Ann. Glaciol., 34 , 247254.

    • Search Google Scholar
    • Export Citation
  • Patterson, S. L., , and H. A. Sievers, 1980: The Weddell–Scotia Confluence. J. Phys. Oceanogr., 10 , 15841610.

  • Pauly, T., , S. Nicol, , I. Higginbottom, , G. Hosie, , and J. Kitchener, 2000: Distribution and abundance of Antarctic krill (Euphausia superba) off East Antarctica (80–150°E) during the Austral summer of 1995/1996. Deep-Sea Res. II, 47 , 24652488.

    • Search Google Scholar
    • Export Citation
  • Richardson, P. L., 1982: Gulf Stream paths measured with free-drifting buoys. J. Phys. Oceanogr., 11 , 9991010.

  • Rio, M-H., , and F. Hernandez, 2003: High-frequency response of wind-driven currents measured by drifting buoys and altimetry over the world ocean. J. Geophys. Res., 108 , 3283. doi:10.1029/2002JC001655.

    • Search Google Scholar
    • Export Citation
  • Robertson, R., 2005: Baroclinic and barotropic tides in the Weddell Sea. Antarct. Sci., 17 , 461474.

  • Schodlok, M. P., , H. H. Hellmer, , G. Rohardt, , and E. Fahrbach, 2006: Weddell Sea iceberg drift: Five years of observations. J. Geophys. Res., 111 , C06018. doi:10.1029/2004JC002661.

    • Search Google Scholar
    • Export Citation
  • Smith, W. H. F., , and D. T. Sandwell, 1997: Global sea floor topography from satellite altimetry and ship depth soundings. Science, 277 , 19561962.

    • Search Google Scholar
    • Export Citation
  • Taylor, G. I., 1921: Diffusion by continuous movements. Proc. London Math. Soc., 20 , 196212.

  • Taylor, G. I., 1953: Dispersion of soluble matter in solvent flowing slowly through a tube. Proc. London Math. Soc., A219 , 186203.

  • Thompson, A. F., 2007: ADELIE cruise report: RRS James Clark Ross cruise 158, 9 February–20 February 2007. UEA Cruise Rep. Series 9, University of East Anglia, Norwich, United Kingdom, 86 pp.

    • Search Google Scholar
    • Export Citation
  • Thompson, A. F., , and K. J. Heywood, 2008: Frontal structure and transport in the northwestern Weddell Sea. Deep-Sea Res. I, 55 , 12291251.

    • Search Google Scholar
    • Export Citation
  • Vallis, G. K., , and M. E. Maltrud, 1993: Generation of mean flows and jets on a beta plane and over topography. J. Phys. Oceanogr., 23 , 13461362.

    • Search Google Scholar
    • Export Citation
  • Wadhams, P., , C. Sear, , D. Crane, , M. Rowe, , S. Morrison, , and D. Limbert, 1989: Basin-scale ice motion and deformation in the Weddell Sea during winter. Ann. Glaciol., 12 , 178186.

    • Search Google Scholar
    • Export Citation
  • Watkins, J. L., , A. W. A. Murray, , and H. I. Daly, 1999: Variation in the distribution of Antarctic krill Euphausia superba around South Georgia. Mar. Ecol. Prog. Ser., 188 , 149160.

    • Search Google Scholar
    • Export Citation
  • Watkins, J. L., , R. Hewitt, , M. Naganobu, , and V. Sushin, 2004: The CCAMLR 2000 survey: A multinational, multi-ship biological oceanography survey of the Atlantic sector of the Southern Ocean. Deep-Sea Res. II, 51 , 12051214.

    • Search Google Scholar
    • Export Citation
  • Whitworth, T., , A. H. Orsi, , S-J. Kim, , W. D. Nowlin, , and R. A. Locarnini, 1998: Water masses and mixing near the Antarctic Slope Front. Ocean, Ice, and Atmosphere: Interactions at the Antarctic Continental Margin, S. S. Jacobs and R. F. Weiss, Eds., Antarctic Research Series, Vol. 75, Amer. Geophys. Union, 1–27.

    • Search Google Scholar
    • Export Citation
  • Zhou, M., , P. P. Niiler, , and J-H. Hu, 2002: Surface currents in the Bransfield and Gerlache Straits, Antarctica. Deep-Sea Res. I, 49 , 267280.

    • Search Google Scholar
    • Export Citation
  • Zhou, M., , P. P. Niiler, , Y. Zhu, , and R. D. Dorland, 2006: The western boundary current in the Bransfield Strait, Antarctica. Deep-Sea Res. I, 53 , 12441252.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 64 64 8
PDF Downloads 55 55 5

Surface Circulation at the Tip of the Antarctic Peninsula from Drifters

View More View Less
  • 1 School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
  • | 2 British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
  • | 3 British Antarctic Survey, Natural Environment Research Council, Cambridge, and School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
  • | 4 Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Oceanografia Fisica, Unidad La Paz, La Paz, Mexico
© Get Permissions
Restricted access

Abstract

An array of 40 surface drifters, drogued at 15-m depth, was deployed in February 2007 to the east of the tip of the Antarctic Peninsula as part of the Antarctic Drifter Experiment: Links to Isobaths and Ecosystems (ADELIE) project. Data obtained from these drifters and from a select number of local historical drifters provide the most detailed observations to date of the surface circulation in the northwestern Weddell Sea. The Antarctic Slope Front (ASF), characterized by a ∼20 cm s−1 current following the 1000-m isobath, is the dominant feature east of the peninsula. The slope front bifurcates when it encounters the South Scotia Ridge with the drifters following one of three paths. Drifters (i) are carried westward into Bransfield Strait; (ii) follow the 1000-m isobath to the east along the southern edge of the South Scotia Ridge; or (iii) become entrained in a large-standing eddy over the South Scotia Ridge. Drifters are strongly steered by contours of f /h (Coriolis frequency/depth) as shown by calculations of the first two moments of displacement in both geographic coordinates and coordinates locally aligned with contours of f /h. An eddy-mean decomposition of the drifter velocities indicates that shear in the mean flow makes the dominant contribution to dispersion in the along-f /h direction, but eddy processes are more important in dispersing particles across contours of f /h. The results of the ADELIE study suggest that the circulation near the tip of the Antarctic Peninsula may influence ecosystem dynamics in the Southern Ocean through Antarctic krill transport and the export of nutrients.

Corresponding author address: Andrew F. Thompson, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom. Email: a.f.thompson@damtp.cam.ac.uk

Abstract

An array of 40 surface drifters, drogued at 15-m depth, was deployed in February 2007 to the east of the tip of the Antarctic Peninsula as part of the Antarctic Drifter Experiment: Links to Isobaths and Ecosystems (ADELIE) project. Data obtained from these drifters and from a select number of local historical drifters provide the most detailed observations to date of the surface circulation in the northwestern Weddell Sea. The Antarctic Slope Front (ASF), characterized by a ∼20 cm s−1 current following the 1000-m isobath, is the dominant feature east of the peninsula. The slope front bifurcates when it encounters the South Scotia Ridge with the drifters following one of three paths. Drifters (i) are carried westward into Bransfield Strait; (ii) follow the 1000-m isobath to the east along the southern edge of the South Scotia Ridge; or (iii) become entrained in a large-standing eddy over the South Scotia Ridge. Drifters are strongly steered by contours of f /h (Coriolis frequency/depth) as shown by calculations of the first two moments of displacement in both geographic coordinates and coordinates locally aligned with contours of f /h. An eddy-mean decomposition of the drifter velocities indicates that shear in the mean flow makes the dominant contribution to dispersion in the along-f /h direction, but eddy processes are more important in dispersing particles across contours of f /h. The results of the ADELIE study suggest that the circulation near the tip of the Antarctic Peninsula may influence ecosystem dynamics in the Southern Ocean through Antarctic krill transport and the export of nutrients.

Corresponding author address: Andrew F. Thompson, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom. Email: a.f.thompson@damtp.cam.ac.uk

Save