• Adcroft, A., C. Hill, and J. Marshall, 1997: Representation of topography by shaved cells in a height coordinate ocean model. Mon. Wea. Rev., 125, 22932315, doi:10.1175/1520-0493(1997)125<2293:ROTBSC>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Brolsma, H., 2012: Bathymetric data collected from Australian Antarctic vessels from 1985-2012. Australian Antarctic Data Centre, CAASM Metadata. [Available online at https://data.aad.gov.au/aadc/metadata/metadata_redirect.cfm?md=/AMD/AU/AAD_Bathy_Acoustic_1985-2012.]

  • Cavalieri, D. J., and S. Martin, 1994: The contribution of Alaskan, Siberian, and Canadian coastal polynyas to the cold halocline layer of the Arctic Ocean. J. Geophys. Res., 99, 18 34318 362, doi:10.1029/94JC01169.

    • Search Google Scholar
    • Export Citation
  • Darelius, E., 2008: Topographic steering of dense overflows: Laboratory experiments with V-shaped ridges and canyons. Deep-Sea Res., 55, 10211034, doi:10.1016/j.dsr.2008.04.008.

    • Search Google Scholar
    • Export Citation
  • Darelius, E., L. Smedsrud, S. Østerhus, A. Foldvik, and T. Gammelsrød, 2009: Structure and variability of the Filchner overflow plume. Tellus, 61A, 446464, doi:10.1111/j.1600-0870.2009.00391.x.

    • Search Google Scholar
    • Export Citation
  • Foldvik, A., and Coauthors, 2004: Ice shelf water overflow and bottom water formation in the southern Weddell Sea. J. Geophys. Res.,109, C02015, doi:10.1029/2003JC002008.

  • Galton-Fenzi, B., J. Hunter, R. Coleman, S. Marsland, and R. Warner, 2012: Modeling the basal melting and marine ice accretion of the Amery Ice Shelf. J. Geophys. Res., 117, C09031, doi:10.1029/2012JC008214.

    • Search Google Scholar
    • Export Citation
  • Gawarkiewicz, G., and D. C. Chapman, 1995: A numerical study of dense water formation and transport on a shallow, sloping continental shelf. J. Geophys. Res., 100, 44894507, doi:10.1029/94JC01742.

    • Search Google Scholar
    • Export Citation
  • Geyer, F., S. Østerhus, B. Hansen, and D. Quadfasel, 2006: Observations of highly regular oscillations in the overflow plume downstream of the Faroe Bank Channel. J. Geophys. Res., 111, C12020, doi:10.1029/2006JC003693.

    • Search Google Scholar
    • Export Citation
  • Guo, C., M. Ilicak, I. Fer, E. Darelius, and M. Berntsen, 2014: Baroclinic instability of the Faroe Bank Channel overflow. J. Phys. Oceanogr., 44, 26962715, doi:10.1175/JPO-D-14-0080.1.

    • Search Google Scholar
    • Export Citation
  • Holland, P. R., 2011: Oscillating dense plumes. J. Phys. Oceanogr., 41, 14651483, doi:10.1175/2011JPO4532.1.

  • Hoppema, M., O. Klatt, W. Roether, E. Fahrbach, K. Bulsiewicz, C. Rodehacke, and G. Rohardt, 2001: Prominent renewal of Weddell Sea Deep Water from a remote source. J. Mar. Res., 59, 257279, doi:10.1357/002224001762882655.

    • Search Google Scholar
    • Export Citation
  • Ilıcak, M., S. Legg, A. Adcroft, and R. Hallberg, 2011: Dynamics of a dense gravity current flowing over a corrugation. Ocean Modell., 38, 7184, doi:10.1016/j.ocemod.2011.02.004.

    • Search Google Scholar
    • Export Citation
  • Jacobs, S. S., and D. T. Georgi, 1977: A Voyage of Discovery. M. Angel, Ed., Pergamon Press, 43–84.

  • Jensen, M. F., I. Fer, and E. Darelius, 2013: Low frequency variability on the continental slope of the southern Weddell Sea. J. Geophys. Res., 118, 42564272, doi:10.1002/jgrc.20309.

    • Search Google Scholar
    • Export Citation
  • Käse, R. H., J. Girton, and T. Sanford, 2003: Structure and variability of the Denmark Strait overflow: Model and observations. J. Geophys. Res., 108, 3181, doi:10.1029/2002JC001548.

    • Search Google Scholar
    • Export Citation
  • Kusahara, K., and K. I. Ohshima, 2009: Dynamics of the wind-driven sea level variation around Antarctica. J. Phys. Oceanogr., 39, 658674, doi:10.1175/2008JPO3982.1.

    • Search Google Scholar
    • Export Citation
  • Kusahara, K., H. Hasumi, and T. Tamura, 2010: Modeling sea ice production and dense shelf water formation in coastal polynyas around East Antarctica. J. Geophys. Res.,115, C10006, doi:10.1029/2010JC006133.

  • Kusahara, K., H. Hasumi, and G. D. Williams, 2011: Impact of the Mertz Glacier Tongue calving on dense water formation and export. Nat. Commun., 2, 159, doi:10.1038/ncomms1156.

    • Search Google Scholar
    • Export Citation
  • Lane-Serff, G. F., and P. G. Baines, 1998: Eddy formation by dense flows on slopes in a rotating fluid. J. Fluid Mech., 363, 229252, doi:10.1017/S0022112098001013.

    • Search Google Scholar
    • Export Citation
  • Mantisi, F., C. Beauverger, A. Poisson, and N. Metzl, 1991: Chlorofluoromethanes in the western Indian sector of the Southern Ocean and their relations with geochemical tracers. Mar. Chem., 35, 151167, doi:10.1016/S0304-4203(09)90014-7.

    • Search Google Scholar
    • Export Citation
  • Marques, G. M., L. Padman, S. R. Springer, S. L. Howard, and T. M. Özgökmen, 2014: Topographic vorticity waves forced by Antarctic dense shelf water outflows. Geophys. Res. Lett., 41, 1247–1254, doi:10.1002/2013GL059153.

    • Search Google Scholar
    • Export Citation
  • Matsumura, Y., and H. Hasumi, 2008: A non-hydrostatic ocean model with a scalable multigrid Poisson solver. Ocean Modell., 24, 1528, doi:10.1016/j.ocemod.2008.05.001.

    • Search Google Scholar
    • Export Citation
  • Matsumura, Y., and H. Hasumi, 2010: Modeling ice shelf water overflow and bottom water formation in the southern Weddell Sea. J. Geophys. Res.,115, C10033, doi:10.1029/2009JC005841.

  • Matsumura, Y., and H. Hasumi, 2011: Dynamics of cross-isobath dense water transport induced by slope topography. J. Phys. Oceanogr., 41, 24022416, doi:10.1175/JPO-D-10-05014.1.

    • Search Google Scholar
    • Export Citation
  • Meijers, A. J. S., A. Klocker, N. L. Bindoff, G. D. Williams, and S. J. Marsland, 2010: The circulation and water masses of the Antarctic shelf and continental slope between 30 and 80°E. Deep-Sea Res. II, 57, 723737, doi:10.1016/j.dsr2.2009.04.019.

    • Search Google Scholar
    • Export Citation
  • Meredith, M. P., R. A. Locarnini, K. A. Van Scoy, A. J. Watson, K. J. Heywood, and B. A. King, 2000: On the sources of Weddell Gyre Antarctic Bottom Water. J. Geophys. Res., 105, 10931104, doi:10.1029/1999JC900263.

    • Search Google Scholar
    • Export Citation
  • Middleton, J. H., and S. E. Humphries, 1989: Thermohaline structure and mixing in the region of Prydz Bay, Antarctica. Deep-Sea Res. I, 36, 12551266, doi:10.1016/0198-0149(89)90104-0.

    • Search Google Scholar
    • Export Citation
  • Nof, D., 1983: The translation of isolated eddies on a sloping bottom. Deep-Sea Res., 30, 171192, doi:10.1016/0198-0149(83)90067-5.

  • Nunes Vaz, R. A., and G. W. Lennon, 1996: Physical oceanography of the Prydz Bay region of Antarctic waters. Deep-Sea Res. I, 43, 603641, doi:10.1016/0967-0637(96)00028-3.

    • Search Google Scholar
    • Export Citation
  • Ohshima, K. I., 1987: Stability of a barotropic jet on a sloping bottom. J. Oceanogr. Soc. Japan, 43, 4960, doi:10.1007/BF02110633.

  • Ohshima, K. I., and Coauthors, 2013: Antarctic Bottom Water production by intense sea-ice formation in the Cape Darnley polynya. Nat. Geosci., 6, 235240, doi:10.1038/ngeo1738.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., and T. Whitworth, 2005: Southern Ocean. Vol. 1, Hydrographic Atlas of the World Ocean Circulation Experiment (WOCE), WOCE International Project Office, 223 pp.

  • Orsi, A. H., G. C. Johnson, and J. L. Bullister, 1999: Circulation, mixing, and production of Antarctic Bottom Water. Prog. Oceanogr., 43, 55109, doi:10.1016/S0079-6611(99)00004-X.

    • Search Google Scholar
    • Export Citation
  • Padman, L., H. A. Fricker, R. Coleman, S. Howard, and L. Erofeeva, 2002: A new tide model for the Antarctic ice shelves and seas. Ann. Glaciol., 34, 247254, doi:10.3189/172756402781817752.

    • Search Google Scholar
    • Export Citation
  • Pedlosky, J., 1987: Geophysical Fluid Dynamics. 2nd ed. Springer-Verlag, 710 pp.

  • Schmitz, J. W. J., 1995: On the interbasin-scale thermohaline circulation. Rev. Geophys., 33, 151173, doi:10.1029/95RG00879.

  • Smagorinsky, J., 1963: General circulation experiments with the primitive equations: I. The basic experiment. Mon. Wea. Rev., 91, 99164, doi:10.1175/1520-0493(1963)091<0099:GCEWTP>2.3.CO;2.

    • Search Google Scholar
    • Export Citation
  • Spall, M. A., and J. F. Price, 1998: Mesoscale variability in Denmark Strait: The PV outflow hypothesis. J. Phys. Oceanogr., 28, 15981623, doi:10.1175/1520-0485(1998)028<1598:MVIDST>2.0.CO;2.

    • Search Google Scholar
    • Export Citation
  • Tamura, T., K. Ohshima, T. Markus, D. Cavalieri, S. Nihashi, and N. Hirasawa, 2007: Estimation of thin ice thickness and detection of fast ice from SSM/I data in the Antarctic Ocean. J. Atmos. Oceanic Technol., 24, 17571772, doi:10.1175/JTECH2113.1.

    • Search Google Scholar
    • Export Citation
  • Tamura, T., K. Oshima, and S. Nihashi, 2008: Mapping of sea ice production for Antarctic coastal polynyas. Geophys. Res. Lett.,35, L07606, doi:10.1029/2007GL032903.

  • Tanaka, K., 2006: Effects of the earth’s rotation and bottom slope on a density current descending a sloping bottom. J. Geophys. Res., 111, C11018, doi:10.1029/2006JC003677.

    • Search Google Scholar
    • Export Citation
  • Tanaka, K., and K. Akitomo, 2001: Baroclinic instability of density current along a sloping bottom and the associated transport process. J. Geophys. Res., 106, 26212638, doi:10.1029/2000JC000214.

    • Search Google Scholar
    • Export Citation
  • Wåhlin, A., 2002: Topographic steering of dense currents with application to submarine canyons. Deep-Sea Res. I, 49, 305320, doi:10.1016/S0967-0637(01)00058-9.

    • Search Google Scholar
    • Export Citation
  • Wåhlin, A., 2004: Downward channeling of dense water in topographic corrugations. Deep-Sea Res. I, 51, 577590, doi:10.1016/j.dsr.2003.11.002.

    • Search Google Scholar
    • Export Citation
  • Wåhlin, A., E. Darelius, C. Cenedese, and G. Lane-Serff, 2008: Laboratory observations of enhanced entrainment in dense overflows in the presence of submarine canyons and ridges. Deep-Sea Res. I, 55, 737750, doi:10.1016/j.dsr.2008.02.007.

    • Search Google Scholar
    • Export Citation
  • Wang, Q., S. Danilov, and J. Schröter, 2009: Bottom water formation in the southern Weddell Sea and the influence of submarine ridges: Idealized numerical simulations. Ocean Modell., 28, 5059, doi:10.1016/j.ocemod.2008.08.003.

    • Search Google Scholar
    • Export Citation
  • Wilchinsky, A. V., and D. L. Feltham, 2009: Numerical simulation of the Filchner overflow. J. Geophys. Res.,114, C12012, doi:10.1029/2008JC005013.

  • Williams, G. D., N. L. Bindoff, S. J. Marsland, and S. R. Rintoul, 2008: Formation and export of dense shelf water from the Adélie depression, East Antarctica. J. Geophys. Res.,113, C04039, doi:10.1029/2007JC004346.

  • Williams, G. D., S. Aoki, S. S. Jacobs, S. R. Rintoul, T. Tamura, and N. L. Bindoff, 2010: Antarctic Bottom Water from the Adélie and George V Land coast, East Antarctica (140–149°E). J. Geophys. Res.,115, C04027, doi:10.1029/2009JC005812.

  • Yabuki, T., T. Suga, K. Hanawa, K. Matsuoka, H. Kiwada, and T. Watanabe, 2006: Possible source of the Antarctic bottom water in the Prydz Bay region. J. Oceanogr., 62, 649655, doi:10.1007/s10872-006-0083-1.

    • Search Google Scholar
    • Export Citation
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A Numerical Investigation of Formation and Variability of Antarctic Bottom Water off Cape Darnley, East Antarctica

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  • 1 Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
  • | 2 Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Chiba, Japan
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Abstract

At several locations around Antarctica, dense water is formed as a result of intense sea ice formation. When this dense water becomes sufficiently denser than the surrounding water, it descends the continental slope and forms Antarctic Bottom Water (AABW). This study presents the AABW formation off the coast of Cape Darnley [Cape Darnley Bottom Water (CDBW)] in East Antarctica, using a nonhydrostatic model. The model is forced for 8 months by a temporally uniform surface salt flux (because of sea ice formation) estimated from Advanced Microwave Scanning Radiometer for Earth Observing System (EOS; AMSR-E) data and a heat budget calculation. The authors reproduce AABW formation and associated periodic downslope flows of dense water. Descending pathways of dense water are largely determined by the topography; most dense water flows into depressions on the continental shelf, advects onto the continental slope, and is steered downslope to greater depths by the canyons. Intense sea ice formation is the most important factor in the formation of AABW off Cape Darnley, and the existence of depressions is of only minor importance for the flux of CDBW. The mechanism responsible for the periodic downslope flow of dense water is further analyzed using an idealized model setup. The period of dense water outflow is regulated primarily by the topographic beta effect.

Current affiliation: Alfred Wegener Institute, Bremerhaven, Germany.

Corresponding author address: Yoshihiro Nakayama, Alfred Wegener Institute, Bussestrasse 24 D-27570 Bremerhaven, Germany. E-mail: yoshihiro.nakayama@awi.de

Abstract

At several locations around Antarctica, dense water is formed as a result of intense sea ice formation. When this dense water becomes sufficiently denser than the surrounding water, it descends the continental slope and forms Antarctic Bottom Water (AABW). This study presents the AABW formation off the coast of Cape Darnley [Cape Darnley Bottom Water (CDBW)] in East Antarctica, using a nonhydrostatic model. The model is forced for 8 months by a temporally uniform surface salt flux (because of sea ice formation) estimated from Advanced Microwave Scanning Radiometer for Earth Observing System (EOS; AMSR-E) data and a heat budget calculation. The authors reproduce AABW formation and associated periodic downslope flows of dense water. Descending pathways of dense water are largely determined by the topography; most dense water flows into depressions on the continental shelf, advects onto the continental slope, and is steered downslope to greater depths by the canyons. Intense sea ice formation is the most important factor in the formation of AABW off Cape Darnley, and the existence of depressions is of only minor importance for the flux of CDBW. The mechanism responsible for the periodic downslope flow of dense water is further analyzed using an idealized model setup. The period of dense water outflow is regulated primarily by the topographic beta effect.

Current affiliation: Alfred Wegener Institute, Bremerhaven, Germany.

Corresponding author address: Yoshihiro Nakayama, Alfred Wegener Institute, Bussestrasse 24 D-27570 Bremerhaven, Germany. E-mail: yoshihiro.nakayama@awi.de
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