• ADD Consortium, cited. 2002: Antarctic Digital Database, version 4.0. SCAR. [Available online at http://www.add.scar.org/.].

  • Ashton, G. D., , and J. F. Kennedy, 1972: Ripples on the underside of river ice covers. J. Hydraul. Div. Amer. Soc. Civ. Eng., HY9 , 16031624.

    • Search Google Scholar
    • Export Citation
  • Beckmann, A., , H. H. Hellmer, , and R. Timmermann, 1999: A numerical model of the Weddell Sea: Large-scale circulation and water mass distribution. J. Geophys. Res., 104 , 2337523391.

    • Search Google Scholar
    • Export Citation
  • Bo Pederson, F., 1980: Dense bottom currents in rotating ocean. J. Hydraul. Div. Amer. Soc. Civ. Eng., 106 , 12911308.

  • Cenedese, C., , J. A. Whitehead, , T. A. Ascarelli, , and M. Ohiwa, 2004: A dense current flowing down a sloping bottom in a rotating fluid. J. Phys. Oceanogr., 34 , 188203.

    • Search Google Scholar
    • Export Citation
  • De Angelis, H., , and P. Skvarca, 2003: Glacier surge after ice shelf collapse. Science, 299 , 15601562.

  • Feltham, D. L., , and M. G. Worster, 1999: Flow-induced morphological instability of a mushy layer. J. Fluid Mech., 391 , 337357.

  • 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.

    • Search Google Scholar
    • Export Citation
  • Gade, H. G., 1979: Melting of ice in sea water: A primitive model with application to the Antarctic ice shelf and icebergs. J. Phys. Oceanogr., 9 , 189198.

    • Search Google Scholar
    • Export Citation
  • Gosink, J. P., , and T. E. Osterkamp, 1983: Measurements and analyses of velocity profiles and frazil ice-crystal rise velocities during periods of frazil-ice formation in rivers. Ann. Glaciol., 4 , 7984.

    • Search Google Scholar
    • Export Citation
  • Grosfeld, K., , R. Gerdes, , and J. Determann, 1997: Thermohaline circulation and interaction between ice shelf cavities and the adjacent open ocean. J. Geophys. Res., 102 , 1559515610.

    • Search Google Scholar
    • Export Citation
  • Hammar, L., , and H. T. Shen, 1995: Frazil evolution in channels. J. Hydraul. Res., 33 , 291306.

  • Hellmer, H. H., , and D. J. Olbers, 1989: A two-dimensional model for the thermohaline circulation under an ice shelf. Antarc. Sci., 1 , 325336.

    • Search Google Scholar
    • Export Citation
  • Holland, D. M., , and A. Jenkins, 1999: Modeling thermodynamic ice–ocean interactions at the base of an ice shelf. J. Phys. Oceanogr., 29 , 17871800.

    • Search Google Scholar
    • Export Citation
  • Holland, P. R., , and D. L. Feltham, 2005: Frazil dynamics and precipitation in a water column with depth-dependent supercooling. J. Fluid Mech., 530 , 101124.

    • Search Google Scholar
    • Export Citation
  • Holland, P. R., , D. L. Feltham, , and S. F. Daly, 2006: On the Nusselt number for frazil ice growth—A correction to “Frazil evolution in channels” by Lars Hammar and Hung-Tao Shen. J. Hydraul. Res., in press.

    • Search Google Scholar
    • Export Citation
  • Jenkins, A., 1991: A one-dimensional model of ice shelf–ocean interaction. J. Geophys. Res., 96 , 2067120677.

  • Jenkins, A., , and A. Bombosch, 1995: Modelling the effects of frazil ice crystals on the dynamics and thermodynamics of Ice Shelf Water plumes. J. Geophys. Res., 100 , 69676981.

    • Search Google Scholar
    • Export Citation
  • Jenkins, A., , and D. M. Holland, 2002a: A model study of ocean circulation beneath Filchner-Ronne Ice Shelf, Antarctica: Implications for bottom water formation. Geophys. Res. Lett., 29 .1193, doi:10.1029/2001GL014589.

    • Search Google Scholar
    • Export Citation
  • Jenkins, A., , and D. M. Holland, 2002b: Correction to “A model study of ocean circulation beneath Filchner-Ronne Ice Shelf, Antarctica: Implications for bottom water formation” by Adrian Jenkins and David M. Holland. Geophys. Res. Lett., 29 .1634, doi:10.1029/2002GL015647.

    • Search Google Scholar
    • Export Citation
  • Jiang, L., , and R. W. Garwood, 1995: A numerical study of three-dimensional dense bottom plumes on a Southern Ocean continental slope. J. Geophys. Res., 100 , 1847118488.

    • Search Google Scholar
    • Export Citation
  • Joughin, I., , and L. Padman, 2003: Melting and freezing beneath Filchner-Ronne Ice Shelf, Antarctica. Geophys. Res. Lett., 30 .1477, doi:10.1029/2003GL016941.

    • Search Google Scholar
    • Export Citation
  • Joughin, I., , W. Abdalati, , and M. Fahnestock, 2004: Large fluctuations in speed on Greenland’s Jakobshavn Isbræ glacier. Nature, 432 , 608610.

    • Search Google Scholar
    • Export Citation
  • Jungclaus, J. H., , and J. O. Backhaus, 1994: Application of a transient reduced gravity plume model to the Denmark Strait outflow. J. Geophys. Res., 99 , 1237512396.

    • Search Google Scholar
    • Export Citation
  • Jungclaus, J. H., , J. O. Backhaus, , and H. Fohrmann, 1995: Outflow of dense water from the Storfjord in Svalbard: A numerical model study. J. Geophys. Res., 100 , 2471924728.

    • Search Google Scholar
    • Export Citation
  • Killworth, P. D., 1977: Mixing on the Weddell Sea continental slope. Deep-Sea Res., 24 , 427448.

  • Killworth, P. D., , and N. R. Edwards, 1999: A turbulent bottom boundary layer code for use in numerical ocean models. J. Phys. Oceanogr., 29 , 12211238.

    • Search Google Scholar
    • Export Citation
  • Kochergin, V. P., 1987: Three-dimensional prognostic models. Three-Dimensional Coastal Ocean Models, N. S. Heaps, Ed., Coastal and Estuarine Studies Series, Vol. 4, Amer. Geophys. Union, 201–208.

  • Lambrecht, A., , C. Meyer, , H. Oerter, , and U. Nixdorf, 1999: Investigations of the mass balance of the southeastern Ronne Ice Shelf, Antarctica. Ann. Glaciol., 29 , 250254.

    • 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.

  • Lewis, E. L., , and R. G. Perkin, 1983: Supercooling and energy exchange near the Arctic Ocean surface. J. Geophys. Res., 88 , 76817685.

    • Search Google Scholar
    • Export Citation
  • MacAyeal, D. R., 1984: Numerical simulations of the Ross Sea tides. J. Geophys. Res., 89 , 607615.

  • MacAyeal, D. R., 1985: Evolution of tidally triggered meltwater plumes below ice shelves. Oceanology of the Antarctic Continental Shelf, S. S. Jacobs, Ed., Antarctic Research Series, Vol. 43, Amer. Geophys. Union, 133–143.

  • McCave, I. N., , and S. A. Swift, 1976: A physical model for the rate of deposition of fine-grained sediments in the deep sea. Geol. Soc. Amer. Bull., 87 , 541546.

    • Search Google Scholar
    • Export Citation
  • Mellor, G. L., , and P. A. Durbin, 1975: The structure and dynamics of the ocean surface mixed layer. J. Phys. Oceanogr., 5 , 718728.

  • Nicholls, K. W., 1996: Temperature variability beneath Ronne Ice Shelf, Antarctica, from thermistor cables. J. Geophys. Res., 101 , 11991210.

    • Search Google Scholar
    • Export Citation
  • Nicholls, K. W., 1997: Predicted reduction in basal melt rates of an Antarctic ice shelf in a warmer climate. Nature, 388 , 460462.

  • Nicholls, K. W., , and A. Jenkins, 1993: Temperature and salinity beneath Ronne Ice Shelf, Antarctica. J. Geophys. Res., 98 , 2255322568.

    • Search Google Scholar
    • Export Citation
  • Nicholls, K. W., , and S. Østerhus, 2004: Interannual variability and ventilation timescales in the ocean cavity beneath Filchner-Ronne Ice Shelf, Antarctica. J. Geophys. Res., 109 .C04014, doi:10.1029/2003JC002149.

    • Search Google Scholar
    • Export Citation
  • Nicholls, K. W., , K. Makinson, , and S. Østerhus, 2004: Circulation and water masses beneath the northern Ronne Ice Shelf, Antarctica. J. Geophys. Res., 109 .C12017, doi:10.1029/2004JC002302.

    • Search Google Scholar
    • Export Citation
  • Nøst, O. A., , and A. Foldvik, 1994: A model of ice shelf–ocean interaction with application to the Filchner-Ronne and Ross Ice Shelves. J. Geophys. Res., 99 , 1424314254.

    • Search Google Scholar
    • Export Citation
  • Oerter, H., , J. Kipfstuhl, , J. Determann, , H. Miller, , D. Wagenbach, , A. Minikin, , and W. Graf, 1992: Evidence for basal marine ice in the Filchner-Ronne Ice Shelf. Nature, 358 , 399401.

    • Search Google Scholar
    • Export Citation
  • Orsi, A. H., , G. C. Johnson, , and J. L. Bullister, 1999: Circulation, mixing, and production of Antarctic Bottom Water. Progress in Oceanography, Vol. 43, Pergamon, 55–109.

  • Payne, A. J., , A. Vieli, , A. P. Shepherd, , D. J. Wingham, , and E. Rignot, 2004: Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans. Geophys. Res. Lett., 31 .L23401, doi:10.1029/2004GL021284.

    • Search Google Scholar
    • Export Citation
  • Ramming, H-G., , and Z. Kowalik, 1980: Numerical Modelling of Marine Hydrodynamics. Elsevier, 369 pp.

  • Rivaro, P., , R. Frache, , A. Bergamasco, , and R. Hohmann, 2003: Dissolved oxygen, NO and PO as tracers for Ross Sea Ice Shelf Water overflow. Antarc. Sci., 15 , 399404.

    • Search Google Scholar
    • Export Citation
  • Sandhäger, H., , D. G. Vaughan, , and A. Lambrecht, 2004: Meteoric, marine and total ice thickness maps of Filchner-Ronne-Schelfeis, Antarctica. FRISP Rep. 15, L. H. Smedsrud, Ed., Bjerknes Centre for Climate Research, Bergen, Norway, 23–39.

  • Shepherd, A. P., , D. J. Wingham, , A. J. Payne, , and P. Skvarca, 2003: Larsen ice shelf has progressively thinned. Science, 302 , 856859.

  • Shepherd, A., , D. Wingham, , and E. Rignot, 2004: Warm ocean is eroding West Antarctic Ice Sheet. Geophys. Res. Lett., 31 .L23402, doi:10.1029/2004GL021106.

    • Search Google Scholar
    • Export Citation
  • Smedsrud, L. H., , and A. Jenkins, 2004: Frazil ice formation in an Ice Shelf Water plume. J. Geophys. Res., 109 .C03025, doi:10.1029/2003JC001851.

    • Search Google Scholar
    • Export Citation
  • Svensson, U., , and A. Omstedt, 1994: Simulation of supercooling and size distribution in frazil ice dynamics. Cold Reg. Sci. Technol., 22 , 221233.

    • Search Google Scholar
    • Export Citation
  • Taylor, G. I., 1920: Tidal friction in the Irish Sea. Philos. Trans. Roy. Soc. London, 220A , 133.

  • Thomas, R. H., 2004: Force-perturbation analysis of recent thinning and acceleration of Jakobshavn Isbræ, Greenland. J. Glaciol., 50 , 5766.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 45 45 13
PDF Downloads 35 35 12

The Effects of Rotation and Ice Shelf Topography on Frazil-Laden Ice Shelf Water Plumes

View More View Less
  • 1 Centre for Polar Observation and Modelling, University College London, London, United Kingdom
© Get Permissions
Restricted access

Abstract

A model of the dynamics and thermodynamics of a plume of meltwater at the base of an ice shelf is presented. Such ice shelf water plumes may become supercooled and deposit marine ice if they rise (because of the pressure decrease in the in situ freezing temperature), so the model incorporates both melting and freezing at the ice shelf base and a multiple-size-class model of frazil ice dynamics and deposition. The plume is considered in two horizontal dimensions, so the influence of Coriolis forces is incorporated for the first time. It is found that rotation is extremely influential, with simulated plumes flowing in near-geostrophy because of the low friction at a smooth ice shelf base. As a result, an ice shelf water plume will only rise and become supercooled (and thus deposit marine ice) if it is constrained to flow upslope by topography. This result agrees with the observed distribution of marine ice under Filchner–Ronne Ice Shelf, Antarctica. In addition, it is found that the model only produces reasonable marine ice formation rates when an accurate ice shelf draft is used, implying that the characteristics of real ice shelf water plumes can only be captured using models with both rotation and a realistic topography.

* Current affiliation: British Antarctic Survey, Cambridge, United Kingdom

+ Current affiliation: Centre for Polar Observation and Modelling, London, and British Antarctic Survey, Cambridge, United Kingdom

Corresponding author address: Dr. Paul R. Holland, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom. Email: p.holland@bas.ac.uk

Abstract

A model of the dynamics and thermodynamics of a plume of meltwater at the base of an ice shelf is presented. Such ice shelf water plumes may become supercooled and deposit marine ice if they rise (because of the pressure decrease in the in situ freezing temperature), so the model incorporates both melting and freezing at the ice shelf base and a multiple-size-class model of frazil ice dynamics and deposition. The plume is considered in two horizontal dimensions, so the influence of Coriolis forces is incorporated for the first time. It is found that rotation is extremely influential, with simulated plumes flowing in near-geostrophy because of the low friction at a smooth ice shelf base. As a result, an ice shelf water plume will only rise and become supercooled (and thus deposit marine ice) if it is constrained to flow upslope by topography. This result agrees with the observed distribution of marine ice under Filchner–Ronne Ice Shelf, Antarctica. In addition, it is found that the model only produces reasonable marine ice formation rates when an accurate ice shelf draft is used, implying that the characteristics of real ice shelf water plumes can only be captured using models with both rotation and a realistic topography.

* Current affiliation: British Antarctic Survey, Cambridge, United Kingdom

+ Current affiliation: Centre for Polar Observation and Modelling, London, and British Antarctic Survey, Cambridge, United Kingdom

Corresponding author address: Dr. Paul R. Holland, British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, United Kingdom. Email: p.holland@bas.ac.uk

Save