Ocean Dynamics

, Volume 63, Issue 9–10, pp 1011–1026 | Cite as

Southern Ocean warming and increased ice shelf basal melting in the twenty-first and twenty-second centuries based on coupled ice-ocean finite-element modelling

Article

Abstract

We utilise a global finite-element sea ice–ocean model (FESOM), focused on the Antarctic marginal seas, to analyse projections of ice shelf basal melting in a warmer climate. Ice shelf–ocean interaction is described using a three-equation system with a diagnostic computation of temperature and salinity at the ice–ocean interface. A tetrahedral mesh with a minimumhorizontal resolution of 4 km and hybrid vertical coordinates is used. Ice shelf draft, cavity geometry, and global ocean bathymetry have been derived from the RTopo-1 data set. The model is forced with the atmospheric output from two climate models: (1) the Hadley Centre Climate Model (HadCM3) and (2) Max Planck Institute’s ECHAM5/MPI-OM coupled climate model. Results from experiments forced with their twentieth century output are used to evaluate the modelled present-day ocean state. Sea ice coverage is largely realistic in both simulations; modelled ice shelf basal melt rates compare well with observations in both cases, but are consistently smaller for ECHAM5/MPI-OM. Projections for future ice shelf basal melting are computed using atmospheric output for the Intergovernmental Panel on Climate Change (IPCC) scenarios E1 and A1B. In simulations forced with ECHAM5 data, trends in ice shelf basal melting are small. In contrast, decreasing convection along the Antarctic coast in HadCM3 scenarios leads to a decreasing salinity on the continental shelf and to intrusions of warm deep water of open ocean origin. In the case of the Filchner–Ronne Ice Shelf (FRIS), this water reaches deep into the cavity, so that basal melting increases by a factor of 4 to 6 compared to the present value of about 90 Gt/year. By the middle of the twenty-second century, FRIS becomes the dominant contributor to total ice shelf basal mass loss in these simulations. Our results indicate that the surface freshwater fluxes on the continental shelves may be crucial for the future of especially the large cold water ice shelves in the Southern Ocean.

Keywords

Southern Ocean Ice shelves Climate prediction 

References

  1. Assmann KM, Hellmer HH, Jacobs SS (2005) Amundsen Sea ice production and transport. J Geophys Res 110:C12013. doi:10.1029/2004JC002797 CrossRefGoogle Scholar
  2. Cavalieri D, Parkinson C, Gloersen P, Zwally HJ (1996) Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS passive microwave data. National Snow and Ice Data Center. Digital media, updated yearlyGoogle Scholar
  3. Connolley WM, Bracegirdle TJ (2007) An Antarctic assessment of IPCC AR4 coupled models. Geophys Res Lett 34:L22505. doi:10.1029/2007GL031648 CrossRefGoogle Scholar
  4. Danilov S, Kivman G, Schröter J (2004) A finite element ocean model: principles and evaluation. Ocean Model 6:125–150CrossRefGoogle Scholar
  5. Danilov S, Kivman G, Schröter J (2005) Evaluation of an eddy-permitting finite-element ocean model in the North Atlantic. Ocean Model 10:35–49. doi:10.1016/j.ocemod.2004.07.006 CrossRefGoogle Scholar
  6. Dupont TK, Alley RB (2005) Assessment of the importance of ice-shelf buttressing to ice-sheet flow. Geophys Res Lett 32:L04503. doi:10.1029/2004GL022024 CrossRefGoogle Scholar
  7. Holland PR, Jenkins A, Holland DM (2010) Ice and ocean processes in the Bellingshausen Sea, Antarctica. J Geophys Res 115:C05020. doi:10.1029/2008JC005219 CrossRefGoogle Scholar
  8. Hellmer HH, Jacobs SS, Jenkins A (1998) Oceanic erosion of a floating Antarctic glacier in the Amundsen Sea. In: Jacobs SS, Weiss RF (eds) Ocean, ice and atmosphere: interactions at the Antarctic continental margin, Antarctic research series, vol 75. American Geophysical Union, Washington, pp 83–99CrossRefGoogle Scholar
  9. Hellmer HH (2004) Impact of Antarctic ice shelf basal melting on sea ice and deep ocean properties. Geophys Res Lett 31:L10307CrossRefGoogle Scholar
  10. Hellmer HH, Kauker F, Timmermann R, Determann J, Rae J (2012) Twenty-first-century warming of a large Antarctic ice-shelf cavity by a redirected coastal current. Nature 485(7397):225–228. doi:10.1038/nature11064 CrossRefGoogle Scholar
  11. Jacobs SS (1991) On the nature and significance of the Antarctic Slope Front. Mar Chem 35:9–24CrossRefGoogle Scholar
  12. Jacobs SS, Hellmer HH, Doake CSM, Jenkins A, Frolich RM (1992) Melting of ice shelves and the mass balance of Antarctica. J Glaciol 38(130):375–387Google Scholar
  13. Jacobs S, Hellmer H, Jenkins A (1996) Antarctic ice sheet melting in the Southeast Pacific. Geophys Res Lett 23(9):957–960CrossRefGoogle Scholar
  14. Jacobs S, Jenkins A, Giulivi C, Dutrieux P (2011a) Stronger sub-ice shelf ocean circulation undermining the Pine Island Glacier. Nat Geosci 4:519–523. doi:10.1038/ngeo1188 CrossRefGoogle Scholar
  15. Jacobs S, Dutrieux P, Giulivi C, Rignot E, Schröder M, Stammerjohn S, Yuan X (2011b) The Getz ice shelf: Antarctica’s top meltwater tap? IGS symposium on interaction of ice sheets and glaciers with the ocean, La Jolla, Abstract 60A127Google Scholar
  16. Jenkins A (1991) A one-dimensional model of ice shelf-ocean interaction. J Geophys Res 96(C11):20671–20677CrossRefGoogle Scholar
  17. Jenkins A, Jacobs SS (2008) Circulation and melting beneath George VI ice shelf, Antarctica. J Geophys Res 113:C04013. doi:10.1029/2007JC004449 CrossRefGoogle Scholar
  18. Jenkins A, Dutrieux P, Jacobs SS, McPhail SD, Perrett JR, Webb AT, White D (2010) Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat. Nat Geosci 3:468–472. doi:10.1038/ngeo890 CrossRefGoogle Scholar
  19. Joughin I, Padman L (2003) Melting and freezing beneath Filchner-Ronne ice shelf, antarctica. Geophys Res Lett 30(9):1477. doi:10.1029/2003GL016941 CrossRefGoogle Scholar
  20. Kusahara K, Hasumi H (2013) Modeling Antarctic ice shelf responses to future climate changes and impacts on the ocean. J Geophys Res Oceans 118. doi:10.1002/jgrc.20166
  21. Meier W, Fetterer F, Knowles K, Savoie M, Brodzik MJ (2006) Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS passive microwave data. National Snow and Ice Data Center. Digital Media, updated quarterlyGoogle Scholar
  22. Nicholls KW, Abrahamsen EP, Heywood KJ, Stansfield K, Østerhus S (2008) High-latitude oceanography using the AUTOSUB autonomous underwater vehicle. Limnol Oceanogr 53 (5, part 2):2309–2320CrossRefGoogle Scholar
  23. Potter JR, Paren JG (1985) Interaction between ice shelf and ocean in George VI Sound, Antarctica. In: Jacobs SS (ed) Oceanology of the Antarctic continental shelf. Antarctic research series, vol 43. American Geophysical Union, Washington, pp 35–58CrossRefGoogle Scholar
  24. Rignot E, Jacobs S, Mouginot J, Scheuchl B (2013) Ice-shelf melting around Antarctica. Science Express 341:266–270. doi:10.1126/science.1235798 CrossRefGoogle Scholar
  25. Sidorenko D, Wang Q, Danilov S, Schröter J (2011) Q9FESOM under coordinated ocean-ice reference experiment forcing. Ocean Dyn 61:881–890. doi:10.1007/s10236-011-0406-7 CrossRefGoogle Scholar
  26. Thoma M, Grosfeld K, Lange MA (2006) The impact of the Eastern Weddell ice shelves on water masses in the eastern Weddell Sea. J Geophys Res 111:C12010. doi:10.1029/2005JC003212 CrossRefGoogle Scholar
  27. Timmermann R, Beckmann A, Hellmer HH (2002a) Simulation of ice-ocean dynamics in the Weddell Sea. Part I: model configuration and validation. J Geophys Res 107(C3). doi:10.1029/2000JC000741
  28. Timmermann R, Hellmer HH, Beckmann A (2002b) Simulation of ice-ocean dynamics in the Weddell Sea. Part II: interannual variability 1985–1993. J Geophys Res 107(C3). doi:10.1029/2000JC000742
  29. Timmermann R, Danilov S, Schröter J, Böning C, Sidorenko D, Rollenhagen K (2009) Ocean circulation and sea ice distribution in a finite element global sea ice–ocean model. Ocean Model 27:114–129. doi:10.1016/j.ocemod.2008.10.009 CrossRefGoogle Scholar
  30. Timmermann R, Le Brocq A, Deen T, Domack E, Dutrieux P, Galton-Fenzi B, Hellmer HH, Humbert A, Jansen D, Jenkins A, Lambrecht A, Makinson K, Niederjasper F, Nitsche F, Noest OA, Smedsrud LH, Smith WHF (2010) A consistent dataset of Antarctic ice sheet topography, cavity geometry, and global bathymetry. Earth Syst Sci Data 2:261–273. doi:10.5194/essd-2-261-2010 CrossRefGoogle Scholar
  31. Timmermann R, Wang Q, Hellmer HH (2012) Ice shelf basal melting in a global finite-element sea ice–ice shelf–ocean model. Ann Glaciol 53(60):303–314. doi:10.3189/2012AoG60A156 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Alfred Wegener Institute, Helmholtz Centre for Polar and Marine ResearchBremerhavenGermany

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