Editorial Type:
Article
Article Type:
Research Article

The Freshwater System West of the Antarctic Peninsula: Spatial and Temporal Changes

Michael P. Meredith British Antarctic Survey, Cambridge, United Kingdom

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Hugh J. Venables British Antarctic Survey, Cambridge, United Kingdom

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Andrew Clarke British Antarctic Survey, Cambridge, United Kingdom

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Hugh W. Ducklow The Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts

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Matthew Erickson The Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts

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Melanie J. Leng Department of Geology, University of Leicester, Leicester, and NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, United Kingdom

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Jan T. M. Lenaerts Institute for Marine and Atmospheric Research, Utrecht, Netherlands

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Michiel R. van den Broeke Institute for Marine and Atmospheric Research, Utrecht, Netherlands

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Print Publication:
01 Mar 2013
DOI:
https://doi.org/10.1175/JCLI-D-12-00246.1
Page(s):
1669–1684
Restricted access

Abstract

Climate change west of the Antarctic Peninsula is the most rapid of anywhere in the Southern Hemisphere, with associated changes in the rates and distributions of freshwater inputs to the ocean. Here, results from the first comprehensive survey of oxygen isotopes in seawater in this region are used to quantify spatial patterns of meteoric water (glacial discharge and precipitation) separately from sea ice melt. High levels of meteoric water are found close to the coast, due to orographic effects on precipitation and strong glacial discharge. Concentrations decrease offshore, driving significant southward geostrophic flows (up to ~30 cm s−1). These produce high meteoric water concentrations at the southern end of the sampling grid, where collapse of the Wilkins Ice Shelf may also have contributed. Sea ice melt concentrations are lower than meteoric water and patchier because of the mobile nature of the sea ice itself. Nonetheless, net sea ice production in the northern part of the sampling grid is inferred; combined with net sea ice melt in the south, this indicates an overall southward ice motion. The survey is contextualized temporally using a decade-long series of isotope data from a coastal Antarctic Peninsula site. This shows a temporal decline in meteoric water in the upper ocean, contrary to expectations based on increasing precipitation and accelerating deglaciation. This is driven by the increasing occurrence of deeper winter mixed layers and has potential implications for concentrations of trace metals supplied to the euphotic zone by glacial discharge. As the regional freshwater system evolves, the continuing isotope monitoring described here will elucidate the ongoing impacts on climate and the ecosystem.

Corresponding author address: Michael P. Meredith, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom. E-mail: mmm@bas.ac.uk

Abstract

Climate change west of the Antarctic Peninsula is the most rapid of anywhere in the Southern Hemisphere, with associated changes in the rates and distributions of freshwater inputs to the ocean. Here, results from the first comprehensive survey of oxygen isotopes in seawater in this region are used to quantify spatial patterns of meteoric water (glacial discharge and precipitation) separately from sea ice melt. High levels of meteoric water are found close to the coast, due to orographic effects on precipitation and strong glacial discharge. Concentrations decrease offshore, driving significant southward geostrophic flows (up to ~30 cm s−1). These produce high meteoric water concentrations at the southern end of the sampling grid, where collapse of the Wilkins Ice Shelf may also have contributed. Sea ice melt concentrations are lower than meteoric water and patchier because of the mobile nature of the sea ice itself. Nonetheless, net sea ice production in the northern part of the sampling grid is inferred; combined with net sea ice melt in the south, this indicates an overall southward ice motion. The survey is contextualized temporally using a decade-long series of isotope data from a coastal Antarctic Peninsula site. This shows a temporal decline in meteoric water in the upper ocean, contrary to expectations based on increasing precipitation and accelerating deglaciation. This is driven by the increasing occurrence of deeper winter mixed layers and has potential implications for concentrations of trace metals supplied to the euphotic zone by glacial discharge. As the regional freshwater system evolves, the continuing isotope monitoring described here will elucidate the ongoing impacts on climate and the ecosystem.

Corresponding author address: Michael P. Meredith, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom. E-mail: mmm@bas.ac.uk
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  • Abram, N. J., R. Mulvaney, and C. Arrowsmith, 2011: Environmental signals in a highly resolved ice core from James Ross Island, Antarctica. J. Geophys. Res., 116, D20116, doi:10.1029/2011JD016147.

    • Search Google Scholar
    • Export Citation

  • Annett, A. L., S. F. Henley, P. van Beck, M. Souhaut, R. Ganeshram, H. J. Venables, M. P. Meredith, and W. Geibert, 2013: Use of radium isotopes to estimate mixing rates and trace sediment inputs to surface waters in northern Marguerite Bay (Antarctic Peninsula). Antarct. Sci., doi:10.1017/S0954102012000892, in press.

    • Search Google Scholar
    • Export Citation

  • Boyd, P. W., and M. J. Ellwood, 2010: The biogeochemical cycle of iron in the ocean. Nat. Geosci., 3, 675–682.

  • Cook, A. J., A. J. Fox, D. G. Vaughan, and J. G. Ferrigno, 2005: Retreating glacier fronts on the Antarctic Peninsula over the past half-century. Science, 308, 541–544.

    • Search Google Scholar
    • Export Citation

  • Craig, H., and L. Gordon, 1965. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. Stable Isotopes in Oceanographic Studies and Paleotemperatures, E. Tongiorgio, Ed., Spoleto, 9–130.

  • Dierssen, H. M., R. C. Smith, and M. Vernet, 2002: Glacial meltwater dynamics in coastal waters west of the Antarctic Peninsula. Proc. Natl. Acad. Sci. USA, 99, 1790–1795.

    • Search Google Scholar
    • Export Citation

  • Ducklow, H. W., and Coauthors, 2012: The marine system of the western Antarctic Penninsula. Antarctic Ecosystems: An Extreme Environment in a Changing World, A. D. Rogers et al., Eds., John Wiley & Sons, 121–159.

  • Edwards, R., and P. Sedwick, 2001: Iron in East Antarctic snow: Implications for atmospheric iron deposition and algal production in Antarctic waters. Geophys. Res. Lett., 28, 3907–3910.

    • Search Google Scholar
    • Export Citation

  • Emery, W. J., C. W. Fowler, and J. A. Maslanik, 1997: Satellite-derived maps of Arctic and Antarctic ice motion: 1988 to 1994. Geophys. Res. Lett., 24, 897–900.

    • Search Google Scholar
    • Export Citation

  • Epstein, S., and T. K. Mayeda, 1953: Variation of 18O content of waters from natural sources. Geochim. Cosmochim. Acta, 4, 213–224.

  • Gille, S., 2008: Decadal-scale temperature trends in the Southern Hemisphere ocean. J. Climate, 21, 4749–4765.

  • Hofmann, E. E., J. M. Klinck, C. M. Lascara, and D. A. Smith, 1996: Water mass distribution and circulation west of the Antarctic Peninsula and including Bransfield Strait. Foundations for Ecological Research West of the Antarctic Peninsula, R. M. Ross, E. E. Hofmann, and L. B. Quetin, Eds., Antarctic Research Series, Vol. 70, Amer. Geophys. Union, 61–80.

  • Holland, P. R., and R. Kwok, 2012: Wind-driven trends in Antarctic sea-ice drift. Nat. Geosci., 5, 872–875, doi:10.1038/ngeo1627.

  • Ivins, E. R., M. M. Watkins, D.-N. Yuan, R. Dietrich, G. Casassa, and A. Rülke, 2011: On-land ice loss and glacial isostatic adjustment at the Drake Passage: 2003–2009. J. Geophys. Res., 116, B02403, doi:10.1029/2010JB007607.

    • Search Google Scholar
    • Export Citation

  • King, J. C., 1994: Recent climate variability in the vicinity of the Antarctic Peninsula. Int. J. Climatol., 14, 357–369.

  • King, J. C., and S. A. Harangozo, 1998: Climate change in the western Antarctic Peninsula since 1945: Observations and possible causes. Ann. Glaciol., 27, 571–575.

    • Search Google Scholar
    • Export Citation

  • Kirchgäßner, A., 2011: An analysis of precipitation data from the Antarctic base Faraday/Vernadsky. Int. J. Climatol., 31, 404–414.

  • Klinck, J. M., 1998: Heat and salt changes on the continental shelf west of the Antarctic Peninsula between January 1993 and January 1994. J. Geophys. Res., 103 (C4), 7617–7636.

    • Search Google Scholar
    • Export Citation

  • Lehmann, M., and U. Siegenthaler, 1991: Equilibrium oxygen- and hydrogen-isotope fractionation between ice and water. J. Glaciol., 57, 23–26.

    • Search Google Scholar
    • Export Citation

  • Lenaerts, J. T. M., M. R. van den Broeke, W. J. van den Berg, E. van Meijgaard, and P. K. Munneke, 2012: A new, high-resolution surface mass balance map of Antarctica (1979–2010) based on regional atmospheric climate modeling. Geophys. Res. Lett., 39, L04501, doi:10.1029/2011GL050713.

    • Search Google Scholar
    • Export Citation

  • Marshall, G. J., A. Orr, N. van Lipzig, and J. King, 2006: The impact of a changing Southern Hemisphere annular mode on Antarctic Peninsula summer temperatures. J. Climate, 19, 5388–5404.

    • Search Google Scholar
    • Export Citation

  • Martinson, D. G., 2011a: Antarctic Circumpolar Current’s role in the Antarctic ice system: An overview. Palaeogeogr. Palaeoclimatol. Palaeoecol., 335–336, 71–74.

    • Search Google Scholar
    • Export Citation

  • Martinson, D. G., 2011b: Transport of warm Upper Circumpolar Deep Water onto the western Antarctic Peninsula continental shelf. Ocean Sci., 8, 433–442.

    • Search Google Scholar
    • Export Citation

  • Martinson, D. G., S. E. Stammerjohn, R. A. Iannuzzi, R. C. Smith, and M. Vernet, 2008: Western Antarctic Peninsula physical oceanography and spatio-temporal variability. Deep-Sea Res. II, 55, 1964–1987.

    • Search Google Scholar
    • Export Citation

  • Meredith, M. P., and J. C. King, 2005: Rapid climate change in the ocean to the west of the Antarctic Penisula during the second half of the 20th century. Geophys. Res. Lett., 32, L19604, doi:10.1029/2005GL024042.

    • Search Google Scholar
    • Export Citation

  • Meredith, M. P., I. A. Renfrew, A. Clarke, J. C. King, and M. A. Brandon, 2004: Impact of the 1997/98 ENSO on upper ocean characteristics in Marguerite Bay, western Antarctic Peninsula. J. Geophys. Res., 109, C09013, doi:10.1029/2003JC001784.

    • Search Google Scholar
    • Export Citation

  • Meredith, M. P., M. A. Brandon, M. I. Wallace, A. Clarke, M. J. Leng, I. A. Renfrew, N. P. M. van Lipzig, and J. C. King, 2008. Variability in the freshwater balance of northern Marguerite Bay, Antarctic Peninsula: Results from δ18O. Deep-Sea Res. II, 55, 309–322.

  • Meredith, M. P., and Coauthors, 2010: Changes in the freshwater composition of the upper ocean west of the Antarctic Peninsula during the first decade of the 21st century. Prog. Oceanogr., 87, 127–143.

    • Search Google Scholar
    • Export Citation

  • Mitchell, B. G., and O. Holm-Hansen, 1991: Observations and modeling of the Antarctic phytoplankton crop in relation to mixing depth. Deep-Sea Res., 38, 981–1007.

    • Search Google Scholar
    • Export Citation

  • Moffat, C., R. Beardsley, W. B. Owens, and N. van Lipzig, 2008: A first description of the Antarctic Peninsula Coastal Current. Deep-Sea Res. II, 55, 277–293.

    • Search Google Scholar
    • Export Citation

  • Moffat, C., B. Owens, and R. C. Beardsley, 2009: On the characteristics of Circumpolar Deep Water intrusions to the west Antarctic Peninsula continental shelf. J. Geophys. Res., 114, C05017, doi:10.1029/2008JC004955.

    • Search Google Scholar
    • Export Citation

  • Montes-Hugo, M., S. C. Doney, H. W. Ducklow, W. Fraser, D. Martinson, S. E. Stammerjohn, and O. Schofield, 2009: Recent changes in phytoplankton communities associated with rapid regional climate change along the western Antarctic Peninsula. Science, 323, 1470–1473.

    • Search Google Scholar
    • Export Citation

  • Morgan, V. I., 1982: Antarctic ice sheet surface oxygen isotope values. J. Glaciol., 28, 315–323.

  • Mulvaney, R., E. C. Pasteur, D. A. Peel, S. Saltzman, and P. Whung, 1992: The ratio of MSA to non-sea-salt sulphate in Antarctic Peninsula ice cores. Tellus, 44B, 295–303.

    • Search Google Scholar
    • Export Citation

  • Nicolas, J. P., and D. H. Bromwich, 2011: Precipitation changes in high southern latitudes from global reanalyses: A cautionary tale. Surv. Geophys., 32, 475–494.

    • Search Google Scholar
    • Export Citation

  • Ostlund, H. G., and G. Hut, 1984: Arctic Ocean water mass balance from isotope data. J. Geophys. Res., 89 (C10), 6373–6381.

  • Padman, L., and Coauthors, 2012: Oceanic controls on the mass balance of Wilkins Ice Shelf, Antarctica. J. Geophys. Res., 117, C01010, doi:10.1029/2011JC007301.

    • Search Google Scholar
    • Export Citation

  • Potter, J. R., and J. G. Paren, 1985: Interaction between ice shelf and ocean in George VI Sound, Antarctica. Oceanology of the Antarctic Continental Shelf, S. Jacobs, Ed., Antarctic Research Series, Vol. 43, Amer. Geophys. Union, 35–58.

  • Pritchard, H. D., S. R. M. Ligtenberg, H. A. Fricker, D. G. Vaughan, M. R. van den Broeke, and L. Padman, 2012: Antarctic ice-sheet loss driven by basal melting of ice shelves. Nature, 484, 502–505.

    • Search Google Scholar
    • Export Citation

  • Raiswell, R., 2011: Iceberg-hosted nanoparticulate Fe in the Southern Ocean mineralogy, origin, dissolution kinetics and source of bioavailable Fe. Deep-Sea Res. II, 58, 1364–1375.

    • Search Google Scholar
    • Export Citation

  • Scambos, T., H. A. Fricker, C. C. Liu, J. Bohlander, J. Fastook, A. Sargent, R. Massom, and A. M. Wu, 2009: Ice shelf disintegration by plate bending and hydro-fracture: Satellite observations and model results of the 2008 Wilkins ice shelf break-ups. Earth Planet. Sci. Lett., 280, 51–60.

    • Search Google Scholar
    • Export Citation

  • Schlosser, P., R. Bayer, A. Foldvik, T. Gammelsrod, G. Rohardt, and K. O. Munnich, 1990: Oxygen 18 and helium as tracers of ice shelf water and water/ice interaction in the Weddell Sea. J. Geophys. Res., 95 (C3), 3253–3263.

    • Search Google Scholar
    • Export Citation

  • Smith, R. C., and S. E. Stammerjohn, 2001: Variations of surface air temperature and sea ice extent in the western Antarctic Peninsula (WAP) region. Ann. Glaciol., 33, 493–500.

    • Search Google Scholar
    • Export Citation

  • Smith, R. C., S. E. Stammerjohn, and K. S. Baker, 1996: Surface air temperature variations in the western Antarctic Peninsula regions. Foundations for Ecological Research West of the Antarctic Peninsula, R. M. Ross, E. E. Hofmann, and L. B. Quetin, Eds., Antarctic Research Series, Vol. 70, Amer. Geophys. Union, 105–121.

  • Stammerjohn, S. E., D. G. Martinson, R. C. Smith, and R. A. Ianuzzi, 2008a: Sea ice in the western Antarctic Peninsula region: Spatio-temporal variability from ecological and climate change perspectives. Deep-Sea Res. II, 55, 2041–2058.

    • Search Google Scholar
    • Export Citation

  • Stammerjohn, S. E., D. G. Martinson, R. C. Smith, X. Yuan, and D. Rind, 2008b: Trends in Antarctic annual sea ice retreat and advance and their relation to El Niño–Southern Oscillation and southern annular mode variability. J. Geophys. Res., 113, C03S90, doi:10.1029/2007JC004269.

    • Search Google Scholar
    • Export Citation

  • Thoma, M., A. Jenkins, D. Holland, and S. Jacobs, 2008: Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica. Geophys. Res. Lett., 35, L18602, doi:10.1029/2008GL034939.

    • Search Google Scholar
    • Export Citation

  • Thomas, E. R., G. J. Marshall, and J. R. McConnell, 2008: A doubling in snow accumulation in the western Antarctic Peninsula. Geophys. Res. Lett., 35, L01706, doi:10.1029/2007GL032529.

    • Search Google Scholar
    • Export Citation

  • Thomas, E. R., P. F. Dennis, T. J. Bracegirdle, and C. Franzke, 2009: Ice core evidence for significant 100-year regional warming on the Antarctic Peninsula. Geophys. Res. Lett., 36, L20704, doi:10.1029/2009GL040104.

    • Search Google Scholar
    • Export Citation

  • Thompson, L. G., D. A. Peel, E. Mosley-Thompson, R. Mulvaney, J. Dai, P. N. Lin, M. E. Davis, and C. F. Raymond, 1994: Climate since AD1510 on Dyer Plateau, Antarctic Peninsula: Evidence for recent climate change. Ann. Glaciol., 20, 420–426.

    • Search Google Scholar
    • Export Citation

  • Tomczak, M., and D. G. B. Large, 1989: Optimum multiparameter analysis of mixing in the thermocline of the eastern Indian Ocean. J. Geophys. Res., 94 (C11), 16 141–16 149.

    • Search Google Scholar
    • Export Citation

  • Turner, J., S. R. Colwell, and S. Harangozo, 1997: Variability of precipitation over the coastal western Antarctic Peninsula from synoptic observations. J. Geophys. Res., 102 (C12), 13 999–14 007.

    • Search Google Scholar
    • Export Citation

  • Turner, J., and Coauthors, 2005: Antarctic climate change during the last 50 years. Int. J. Climatol., 25, 279–294.

  • Turner, J., and Coauthors, 2009: Non-annular atmospheric circulation change induced by stratospheric ozone depletion and its role in the recent increase in Antarctic sea ice extent. Geophys. Res. Lett., 36, L08502, doi:10.1029/2009GL037524.

    • Search Google Scholar
    • Export Citation

  • Turner, J., E. Maksym, A. Phillips, G. J. Marshall, and M. P. Meredith, 2013: The impact of changes in sea ice advance on the large winter warming on the western Antarctic Peninsula. Int. J. Climatol., doi:10.1002/joc.3474, in press.

    • Search Google Scholar
    • Export Citation

  • Vaughan, D. G., 2006: Recent trends in melting conditions on the Antarctic Peninsula and their implications for ice-sheet mass balance and sea level. Arct. Antarct. Alp. Res., 38, 147–152.

    • Search Google Scholar
    • Export Citation

  • Vaughan, D. G., and Coauthors, 2003: Recent rapid regional climate warming on the Antarctic Peninsula. Climatic Change, 60, 243–274.

  • Venables, H. J., A. Clarke, and M. P. Meredith, 2013: Wintertime controls on summer stratification and productivity at the western Antarctic Peninsula. Limnol. Oceanogr., in press.

    • Search Google Scholar
    • Export Citation

  • Wallace, M. I., M. P. Meredith, M. A. Brandon, T. J. Sherwin, A. Dale, and A. Clarke, 2008: On the characteristics of internal tides and coastal upwelling behaviour in Marguerite Bay, west Antarctic Peninsula. Deep-Sea Res. II, 55, 2023–2040.

    • Search Google Scholar
    • Export Citation

  • Weiss, R. F., H. G. Ostlund, and H. Craig, 1979: Geochemical studies of the Weddell Sea. Deep-Sea Res., 26A, 1093–1120.

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