Skip to main content
×
×
Home

Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations

  • N.J. Robinson (a1) (a2) and M.J.M. Williams (a1)
Abstract

Two massive tabular icebergs calved from the Ross Ice Shelf in 2000 (B-15) and 2002 (C-19) and perturbed regional ocean processes for several years. Here we document the ocean's response in McMurdo Sound to the icebergs using in situ data collected before, during and after the icebergs’ residence in the Ross Sea. Departures from typical McMurdo Sound seasonal oceanography included the non-appearance of Antarctic Surface Water in summer, a cooler and more homogeneous water column during winter and ‘super-fresh’ High Salinity Shelf Water that gradually recovered its salinity. We found that each iceberg triggered a distinct response to regional ocean processes. B-15a, the largest piece of iceberg B-15, restricted surface circulation, cooled and freshened the upper water column and reduced melting near the ice shelf front for four years. Iceberg C-19 interrupted the operation of the Ross Sea polynya, from which McMurdo Sound took three to four years to recover, and was responsible for a geographic shift in the dense water formation region for the south-western Ross Sea. These results differ from earlier modelling studies and highlight the challenges of modelling the polar ocean. We also show that one pathway previously thought to supply dense water to the Ross Ice Shelf cavity was not operating at that time.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations
      Available formats
      ×
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations
      Available formats
      ×
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations
      Available formats
      ×
Copyright
Corresponding author
n.robinson@niwa.co.nz
References
Hide All
Ainley, D.G., Ballard, G.Olmastroni, S. 2009. An apparent decrease in the prevalence of “Ross Sea Killer Whales” in the southern Ross Sea. Aquatic Mammals, 35, 335347.
Albrecht, N., Vennell, R., Williams, M., Stevens, C., Langhorne, P., Leonard, G.Haskell, T. 2006. Observation of sub-inertial internal tides in McMurdo Sound, Antarctica. Geophysical Research Letters, 10.1029/2006GL027377.
Arrigo, K.R.van Dijken, G.L. 2003. Impact of iceberg C-19 on Ross Sea primary production. Geophysical Research Letters, 30, 10.1029/2003GL017721.
Arrigo, K.R.van Dijken, G.L. 2004. Annual changes in sea ice, chlorophyll a, and primary production in the Ross Sea, Antarctica. Deep-Sea Research II, 51, 117138.
Arrigo, K.R., van Dijken, G.L., Ainely, D.G., Fahnestock, M.A.Markus, T. 2002. Ecological impact of a large Antarctic iceberg. Geophysical Research Letters, 10.1029/2001GL014160.
Assmann, K.M. 2004. The effect of McMurdo Sound topography on water mass exchange across the Ross Ice Shelf front. Bergen: Bjerknes Centre for Climate Research. Forum for Research into Ice Shelf Processes (FRISP) Report, 15, 5569.
Assmann, K.Timmermann, R. 2005. Variability of dense water formation in the Ross Sea. Ocean Dynamics, 55, 6887.
Assmann, K., Hellmer, H.H.Beckmann, A. 2003. Seasonal variation in circulation and water mass distribution on the Ross Sea continental shelf. Antarctic Science, 15, 311.
Brunt, K.M., Sergienko, O.MacAyeal, D.R. 2006. Observations of unusual fast-ice conditions in the southwest Ross Sea, Antarctica: preliminary analysis of iceberg and storminess effects. Annals of Glaciology, 44, 183187.
Cockrem, J., Potter, M.Candy, E. 2006. Corticosterone in relation to body mass in Adelie penguins (Pygoscelis adeliae) affected by unusual sea ice conditions at Ross Island, Antarctica. General and Comparative Endocrinology, 149, 244252.
Dinniman, M.S., Klink, J.M.Smith, W.O. Jr 2007. The influence of sea ice cover and icebergs on circulation and water mass formation in a numerical circulation model of the Ross Sea, Antarctica. Journal of Geophysical Research, 10.1029/2006JC004036.
Fusco, G., Budillon, G.Spezie, G. 2009. Surface heat fluxes and thermohaline variability in the Ross Sea and in Terra Nova Bay polynya. Continental Shelf Research, 29, 18871895.
Gordon, A.L., Orsi, A.H., Muench, R., Huber, B.A., Zambianchi, E.Visbeck, M. 2009. Western Ross Sea continental slope gravity currents. Deep-Sea Research II, 56, 796817.
Grosfeld, K., Gerdes, R.Determann, J. 1997. Thermohaline circulation and interaction between ice shelf cavities and the adjacent open ocean. Journal of Geophysical Research, 102, 15 59515 610.
Harangozo, S.A.Connolley, W.M. 2006. The role of the atmospheric circulation in the record minimum extent of open water in the Ross Sea in the 2003 austral summer. Atmosphere-Ocean, 44, 8397.
Horgan, H., Naish, T., Bannister, S., Balfour, N.Wilson, G. 2005. Seismic stratigraphy of the Plio-Pleistocene Ross Island flexural moat-fill: a prognosis for ANDRILL Program drilling beneath McMurdo-Ross Ice Shelf. Global and planetary change, 45, 8397.
Hunt, B.M., Heofling, K.Cheng, C.C. 2003. Annual warming episodes in seawater temperature in McMurdo Sound in relationship to endogenous ice in notothenioid fish. Antarctic Science, 15, 333338.
Jacobs, S.S.Giulivi, C.F. 1998. Interannual ocean and sea ice variability in the Ross Sea. Antarctic Research Series, 75, 135150.
Jacobs, S.S., Fairbanks, R.G.Horibe, Y. 1985. Origin and evolution of water masses near the Antarctic continental margin: evidence from H182 O/ H162 O ratios in seawater. Antarctic Research Series, 43, 5985.
Jacobs, S.S., Giulivi, C.F.Mele, P.A. 2002. Freshening of the Ross Sea during the late 20th century. Science, 297, 386389.
Jacobs, S.S., Gordon, A.L.Ardai, J. 1979. Circulation and melting beneath the Ross Ice Shelf. Science, 203, 439443.
Joughin, I.MacAyeal, D.R. 2005. Calving of large tabular icebergs from ice shelf rift systems. Geophysical Research Letters, 10.1029/2004GL020978.
Kenneally, J.P.Hughes, T. 2006. Calving giant icebergs: old principles, new applications. Antarctic Science, 18, 409419.
Kern, S. 2009. Wintertime Antarctic coastal polynya area: 1992 to 2008. Geophysical Research Letters, 10.1029/2009GL038062.
Keys, H.J.R., Jacobs, S.S.Barnett, D. 1990. The calving and drift of iceberg B-9 in the Ross Sea, Antarctica. Antarctic Science, 2, 243257.
Kooyman, G.L., Ainley, D.G., Ballard, G.Ponganis, P.J. 2007. Effects of giant icebergs on two emperor penguin colonies in the Ross Sea, Antarctica. Antarctic Science, 19, 3138.
Kurtz, D.D.Bromwich, D.H. 1985. A recurring, atmospherically forced polynya in Terra Nova Bay. Antarctic Research Series, 43, 177201.
Leonard, G.H., Purdie, C.R., Langhorne, P.J., Haskell, T.G., Williams, M.J.M.Frew, R.D. 2006. Observations of platelet ice growth and oceanographic conditions during the winter of 2003 in McMurdo Sound, Antarctica. Journal of Geophysical Research, 10.1029/2005JC002952.
Leonard, G.H., Langhorne, P.J., Williams, M.J.M., Vennell, R., Purdie, C.R., Dempsey, D.E., Haskell, T.G.Frew, R.D. 2011. Evolution of supercooling under coastal Antarctic sea ice during winter. Antarctic Science, 23, 399409.
Lewis, E.L.Perkin, R.G. 1985. The winter oceanography of McMurdo Sound, Antarctica. Antarctic Research Series, 43, 145165.
MacAyeal, D.R., Okal, M.H., Thom, J.E., Brunt, K.M., Kim, Y.-J.Bliss, A.K. 2008. Tabular iceberg collisions within the coastal regime. Journal of Glaciology, 54, 371386.
Mahoney, A.R., Gough, A.J., Langhorne, P.J., Robinson, N.J., Stevens, C.L., Williams, M.M.J.Haskell, T.G. 2011. The seasonal appearance of ice shelf water in coastal Antarctica and its effect on sea ice growth. Journal of Geophysical Research, 10.1029/2011JC007060.
Martin, S., Drucker, R.S.Kwok, R. 2007. The areas and ice production of the western and central Ross Sea polynyas, 1992–2002, and their relation to the B-15 and C-19 iceberg events of 2000 and 2002. Journal of Marine Systems, 68, 201214.
McCrae, I.R. 1984. A summary of glaciological measurements made between 1960 and 1984 on the McMurdo Ice Shelf, Antarctica. School of Engineering Report 360. Auckland: Department of Theoretical and Applied Mechanics, University of Auckland, 93 pp.
McKay, R., Dunbar, G., Naish, T., Barrett, P., Carter, L.Harper, M. 2008. Retreat history of the Ross Ice Sheet (Shelf) since the Last Glacial Maximum from deep-basin sediment cores around Ross Island. Palaeogeography, Palaeoclimatology, Palaeoecology, 260, 245261.
Orsi, A.H.Wiederwohl, C.L. 2009. A recount of Ross Sea waters. Deep-Sea Research II, 56, 778795.
Pyne, A.R., Ward, B.L., MacPherson, A.J.Barrett, P.J. 1985. McMurdo Sound bathymetry. New Zealand Oceanographic Institute Chart, Miscellaneous Series, No. 62. 1:250 000. Wellington: Oceanographic Institute, Antarctic Research Centre.
Remy, J.-P., Becquevort, S., Haskell, T.G.Tison, J.-L. 2008. Impact of the B-15 iceberg “stranding event” on the physical and biological properties of sea ice in McMurdo Sound, Ross Sea, Antarctica. Antarctic Science, 20, 593604.
Robinson, N.J. 2012. Circulation, mixing and interactions in the ocean near an Antarctic ice shelf. PhD thesis, University of Otago, 249 pp. [Unpublished.]
Robinson, N.J., Williams, M.J.M., Barrett, P.J.Pyne, A.R. 2010. Observations of flow and ice-ocean interaction beneath the McMurdo Ice Shelf, Antarctica. Journal of Geophysical Research, 10.1029/2008JC005255.
Seibel, B.A.Dierssen, H.M. 2003. Cascading trophic impacts of reduced biomass in the Ross Sea, Antarctica: just the tip of the iceberg? Biology Bulletin, 205, 9397.
Silva, T.A.M., Bigg, G.R.Nicholls, K.W. 2006. Contribution of giant icebergs to the Southern Ocean freshwater flux. Journal of Geophysical Research, 10.1029/2004JC002843.
Tamura, T., Ohshima, K.I.Nihashi, S. 2008. Mapping of sea ice production for Antarctic coastal polynyas. Geophysical Research Letters, 10.1029/2010JC006586.
Tressler, W.L.Ommundsen, A.M. 1962. Seasonal oceanographic studies in McMurdo Sound, Antarctica. Technical report. Washington DC: United States Navy Hydrographic Offce, 158 pp.
Turnbull, I.D. 2010. Drift of large tabular icebergs in response to atmospheric surface pressure gradients, an observational study. Antarctic Science, 22, 199208.
Van Woert, M.L. 1999. Wintertime expansion and contraction of the Terra Nova Bay polynya. In Spezie, G. & Manzella, G.M.R., eds. Oceanography of the Ross Sea, Antarctica. Milan: Springer, 145–164.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Antarctic Science
  • ISSN: 0954-1020
  • EISSN: 1365-2079
  • URL: /core/journals/antarctic-science
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed