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The annual glaciohydrology cycle in the ablation zone of the Greenland ice sheet: Part 2. Observed and modeled ice flow

  • William Colgan (a1) (a2), Harihar Rajaram (a3), Robert S. Anderson (a4) (a5), Konrad Steffen (a1) (a2), H. Jay Zwally (a6), Thomas Phillips (a1) and Waleed Abdalati (a1) (a2) (a7)...
Abstract

Ice velocities observed in 2005/06 at three GPS stations along the Sermeq Avannarleq flowline, West Greenland, are used to characterize an observed annual velocity cycle. We attempt to reproduce this annual ice velocity cycle using a 1-D ice-flow model with longitudinal stresses coupled to a 1-D hydrology model that governs an empirical basal sliding rule. Seasonal basal sliding velocity is parameterized as a perturbation of prescribed winter sliding velocity that is proportional to the rate of change of glacier water storage. The coupled model reproduces the broad features of the annual basal sliding cycle observed along this flowline, namely a summer speed-up event followed by a fall slowdown event. We also evaluate the hypothesis that the observed annual velocity cycle is due to the annual calving cycle at the terminus. We demonstrate that the ice acceleration due to a catastrophic calving event takes an order of magnitude longer to reach CU/ETH (‘Swiss’) Camp (46 km upstream of the terminus) than is observed. The seasonal acceleration observed at Swiss Camp is therefore unlikely to be the result of velocity perturbations propagated upstream via longitudinal coupling. Instead we interpret this velocity cycle to reflect the local history of glacier water balance.

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References
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Anderson, RS and 6 others (2004) Strong feedbacks between hydrology and sliding of a small alpine glacier. J. Geophys. Res, 109(F3), F03005 (doi: 10.1029/2004JF000120)
Bamber, JL, Layberry, RL and Gogineni, SP (2001) A new ice thickness and bed data set for the Greenland ice sheet. 1. Measurement, data reduction, and errors. J. Geophys. Res., 106(D24), 33 773-33 780
Bartholomaus, TC, Anderson, RS and Anderson, SP (2008) Response of glacier basal motion to transient water storage. Nature Geosci., 1(1), 33-37
Bartholomaus, TC, Anderson, RS and Anderson, SP (2011) Growth and collapse of the distributed subglacial hydrologic system of Kennicott Glacier, Alaska, and its effects on basal motion. J. Glaciol, 57(206), 985-1002
Bartholomew, I, Nienow, P, Mair, D, Hubbard, A, King, MA and Sole, A (2010) Seasonal evolution of subglacial drainage and acceleration in a Greenland outlet glacier. Nature Geosci., 3(6), 408-411
Bindschadler, R (1983) The importance of pressurized subglacial water in separation and sliding at the glacier bed. J. Glaciol., 29(101), 3-19
Burgess, EW and 6 others (2010) A spatially calibrated model of annual accumulation rate on the Greenland Ice Sheet (19582007). J. Geophys. Res., 115(F2), F02004 (doi: 10.1029/ 2009JF001293)
Catania, GA and Neumann, TA (2010) Persistent englacial drainage features in the Greenland Ice Sheet. Geophys. Res. Lett., 37(2), L02501 (doi: 10.1029/2009GL041108)
Colgan, WT, Phillips, TP, Anderson, RS, Zwally, HJ, Abdalati, W and Rajaram, H (2009) Similarities in basal sliding between Greenland and Alpine glaciers. [Abstr. C23B-0499] Eos, 90(52) Fall Meet. Suppl.
Colgan, W and 7 others (2011a) The annual glaciohydrology cycle in the ablation zone of the Greenland ice sheet: Part 1. Hydrology model. J. Glaciol., 57(204), 697-709
Colgan, W and 7 others (2011b) An increase in crevasse extent, West Greenland: hydrologic implications. Geophys. Res. Lett., 38(18), L18502 (doi: 10.1029/2011GL048491)
Fausto, RS, Ahlstrom, AP, Van As, D, Boggild, CE and Johnsen, SJ (2009) A new present-day temperature parameterization for Greenland. J. Glaciol., 55(189), 95-105
Flowers, GE and Clarke, GKC (2002) A multicomponent coupled model of glacier hydrology: 1. Theory and synthetic examples. J. Geophys. Res, 107(B11), 2287 (doi: 10.1029/2001JB001122)
Fountain, AG and Walder, JS (1998) Water flow through temperate glaciers. Rev. Geophys., 36(3), 299-328
Gagliardini, O, Cohen, D, Raback, P and Zwinger, T (2007) Finite- element modeling of subglacial cavities and related friction law. J. Geophys. Res., 112(F2), F02027 (doi: 10.1029/2006JF000576)
Glen, JW (1955) The creep of polycrystalline ice. Proc. R. Soc. London, Ser. A, 228(1175), 519-538
Holland, DM, Thomas, RH, de Young, B, Ribergaard, MH and Lyberth, B (2008) Acceleration of Jakobshavn Isbræ triggered by warm subsurface ocean waters. Nature Geosci., 1(10), 659-664
Hooke, RLeB (2005) Principles of glacier mechanics. Second edition. Cambridge University Press, Cambridge
Howat, IM, Tulaczyk, S, Waddington, E and Bjornsson, H (2008a) Dynamic controls on glacier basal motion inferred from surface ice motion. J. Geophys. Res., 113(F3), F03015 (doi: 10.1029/ 2007JF000925)
Howat, IM, Joughin, I, Fahnestock, M, Smith, BE and Scambos, T (2008b) Synchronous retreat and acceleration of southeast Greenland outlet glaciers 2000-2006: ice dynamics and coupling to climate. J. Glaciol., 54(187), 646-660
Huybrechts, P (1994) The present evolution of the Greenland ice sheet: an assessment by modelling. Global Planet. Change, 9(1-2), 39-51
Huybrechts, P, Letreguilly, A and Reeh, N (1991) The Greenland ice sheet and greenhouse warming. Global Planet. Change, 3(4), 399-412
Iken, A (1981) The effect of the subglacial water pressure on the sliding velocity of a glacier in an idealized numerical model. J. Glaciol., 27(97), 407-421
Iken, A and Bindschadler, RA (1986) Combined measurements of subglacial water pressure and surface velocity of Findelen- gletscher, Switzerland: conclusions about drainage system and sliding mechanism. J. Glaciol., 32(110), 101-119
Iken, A, Rothlisberger, H, Flotron, A and Haeberli, W (1983) The uplift of Unteraargletscher at the beginning of the melt season - a consequence of water storage at the bed? J. Glaciol., 29(101), 28-47
Jansson, P, Hock, R and Schnieder, T (2003) The concept of glacier storage: a review. J. Hydrol., 282(1-4), 116-129
Joughin, I, Das, SB, King, MA, Smith, BE, Howat, IM and Moon, T (2008) Seasonal speedup along the western flank of the Greenland Ice Sheet. Science, 320(5877), 781-783
Joughin, I, Smith, BE, Howat, IM, Scambos, T and Moon, T (2010) Greenland flow variability from ice-sheet-wide velocity mapping. J. Glaciol., 56(197), 415-430
Kamb, B (1970) Sliding motion of glaciers: theory and observation. Rev. Geophys. Space Phys., 8(4), 673-728
Kamb, B, Engelhardt, H, Fahnestock, MA, Humphrey, N, Meier, M and Stone, D (1994) Mechanical and hydrologic basis for the rapid motion of a large tidewater glacier. 2. Interpretation. J. Geophys. Res., 99(B8), 15 231-15 244
Kessler, MA and Anderson, RS (2004) Testing a numerical glacial hydrological model using spring speed-up events and outburst floods. Geophys. Res. Lett., 31(18), L18503 (doi: 10.1029/ 2004GL020622)
Larson, KM, Plumb, J, Zwally, J and Abdalati, W (2001) Analysis of GPS data collected on the Greenland ice sheet. Polar Geogr., 25(1), 22-40
Luthi, M, Funk, M, Iken, A, Gogineni, S and Truffer, M (2002) Mechanisms of fast flow in Jakobshavn Isbr*, West Greenland. Part III. Measurements of ice deformation, temperature and cross-borehole conductivity in boreholes to the bedrock. J. Glaciol., 48(162), 369-385
Marshall, SJ, Bjornsson, H, Flowers, GE and Clarke, GKC (2005) Simulation of Vatnajokull ice cap dynamics. J. Geophys. Res., 110(F3), F03009 (doi: 10.1029/2004JF000262)
McGrath, D, Colgan, W, Steffen, K, Lauffenburger, P and Balog, J (2011) Assessing the summer water budget of a moulin basin in the Sermeq Avannarleq ablation region, Greenland ice sheet. J. Glaciol., 57(205), 954-964
Nick, FM, Vieli, A, Howat, IM and Joughin, I (2009) Large-scale changes in Greenland outlet glacier dynamics triggered at the terminus. Nature Geosci., 2(2), 110-114
Ohmura, A (2001) Physical basis for the temperature-based melt- index method. J. Appl. Meteorol., 40(4), 753-761
Parizek, BR and Alley, RB (2004) Implications of increased Greenland surface melt under global-warming scenarios: ice-sheet simulations. Quat. Sci. Rev., 23(9-10), 1013-1027
Paterson, WSB (1991) Why ice-age ice is sometimes ‘soft’. Cold Reg. Sci. Technol., 20(1), 75-98
Paterson, WSB (1994) The physics of glaciers. Third edition. Elsevier, Oxford
Pfeffer, WT, Meier, MF and Illangasekare, TH (1991) Retention of Greenland runoff by refreezing: implications for projected future sea level change. J. Geophys. Res., 96(C12), 22 117-22 124
Pimentel, S and Flowers, GE (2010) A numerical study of hydrologically driven glacier dynamics and subglacial flooding. Proc. R. Soc. London, Ser. A, 467(2126), 537-558
Plummer, J, Gogineni, S, Van der Veen, C, Leuschen, C and Li, J (2008) Ice thickness and bed map for Jakobshavn Isbr*. CReSIS Tech. Rep. 2008-1.
Price, SF, Payne, AJ, Catania, GA and Neumann, TA (2008) Seasonal acceleration of inland ice via longitudinal coupling to marginal ice. J. Glaciol., 54(185), 213-219
Reeh, N (1985) Was the Greenland ice sheet thinner in the Late Wisconsinan than now? Nature, 317(6040), 797-799
Rignot, E, Koppes, M and Velicogna, I (2010) Rapid submarine melting of the calving faces of West Greenland glaciers. Nature Geosci., 3(3), 141-218
Ritz, C, Fabre, A and Letreguilly, A (1997) Sensitivity of a Greenland ice sheet model to ice flow and ablation parameters: consequences for the evolution through the last glacial cycle. Climate Dyn., 13(1), 11-23
Scambos, TA and Haran, T (2002) An image-enhanced DEM of the Greenland ice sheet. Ann. Glaciol., 34, 291-298
Schoof, C (2005) The effect of cavitation on glacier sliding. Proc. R. Soc. London, Ser. A, 461(2055), 609-627
Schoof, C (2010) Ice-sheet acceleration driven by melt supply variability. Nature, 468(7325), 803-806
Steffen, K and Box, J (2001) Surface climatology of the Greenland ice sheet: Greenland Climate Network 1995-1999. J. Geophys. Res., 106(D24), 33 951-33 964
Sundal, AV, Shepherd, A, Nienow, P, Hanna, E, Palmer, S and Huybrechts, P (2011) Melt-induced speed-up of Greenland ice sheet offset by efficient subglacial drainage. Nature, 469(7331), 521-524
Thomsen, HH, Thorning, L and Braithwaite, RJ (1988) Glacier- hydrological conditions on the inland ice north-east of Jacobshavn/Ilulissat, West Greenland. Rapp. Gr0nl. Geol. Unders. 138
Van der Veen, CJ (1987) Longitudinal stresses and basal sliding: a comparative study. In Van der Veen, CJ and Oerlemans, J eds. Dynamics of the West Antarctic ice sheet. D. Reidel Publishing Co., Dordrecht, 223-248
Weertman, J (1957) On the sliding of glaciers. J. Glaciol., 3(21), 33-38
Zwally, HJ, Abdalati, W, Herring, T, Larson, K, Saba, J and Steffen, K (2002) Surface melt-induced acceleration of Greenland ice- sheet flow. Science, 297(5579), 218-222
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