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Modeling surface-roughness/solar-ablation feedback: application to small-scale surface channels and crevasses of the Greenland ice sheet

  • L. Maclagan Cathles (a1), Dorian S. Abbot (a1), Jeremy N. Bassis (a2) and Douglas R. MacAyeal (a1)

Abstract

Surface roughness enhances the net ablation rate associated with direct solar radiation relative to smooth surfaces, because roughness allows solar energy reflected from one part of the surface to be absorbed by another part. In this study we examine the feedback between solar-radiation-driven ablation and growth of surface roughness on the Greenland ice sheet, using a numerical model of radiative transfer. Our experiments extend previous work by examining: (1) the effects of diurnal and seasonal variation of solar zenith angle and azimuth relative to incipient roughness features, (2) the evolution of roughness geometry in response to radiatively driven ablation and (3) the relative solar energy collection efficiencies of various roughness geometries and geographic locations and orientations. A notable result of this examination is that the time evolution of the aspect ratio of surface features under solar-driven ablation collapses onto a roughly universal curve that depends only on latitude, not the detailed shape of the feature. The total enhancement of surface melt relative to a smooth surface over a full ablation season varies with this ratio, and this dependence suggests a way to parameterize roughness effects in large-scale models that cannot treat individual roughness features. Overall, our model results suggest that surface roughness at the latitudes spanned by the Greenland ice sheet tends to dissipate as the ablation season progresses.

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References

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Anslow, F.S., Hostetler, S., Bidlake, W.R. and Clark, P.U.. 2008. Distributed energy balance modeling of South Cascade Glacier, Washington and assessment of model uncertainty. J. Geophys. Res., 113(F2), F02019. (10.1029/2007JF000850.)
Arnold, N.S., Rees, W.G., Hodson, A.J. and Kohler, J.. 2006. Topographic controls on the surface energy balance of a high Arctic valley glacier. J. Geophys. Res., 111(F2), F02011. (10.1029/2005JF000426.)
Betterton, M.D. 2001. Theory of structure formation in snowfields motivated by penitentes, suncups, and dirt cones. Phys. Rev. E, 63(5), 056129.
Harper, J., Humphrey, N., Brown, J. and Pfeffer, N.. 2011. Field measurement of meltwater retention on the Greenland ice sheet. Ann. Glaciol., 59 (see paper in this issue).
Hock, R. and Holmgren, B.. 2005. A distributed surface energy-balance model for complex topography and its application to Storglaciären, Sweden. J. Glaciol., 51(172), 25–36.
Holmes, G.W. 1955. Morphology and hydrology of the Mint Julep area, southwest Greenland. In ProjectMint Julep. Part II. Maxwell Air Force Base, AL, Air University, 1–50.
Lampkin, D.J. and Vandenberg, J.. In press. A preliminary investigation of the influence of basal and surface topography on supraglacial lake distribution near Jakobshavn Isbræ, western Greenland. Hydrol. Process. (10.1002/hyp.8170.)
Lüthje, M., Pedersen, L.T., Reeh, N. and Greuell, W.. 2006. Modelling the evolution of supraglacial lakes on the West Greenland ice-sheet margin. J. Glaciol., 52(179), 608–618.
MacClune, K.L., Fountain, A.G., Kargel, J.S. and MacAyeal, D.R.. 2003. Glaciers of the McMurdo dry valleys: terrestrial analog for Martian polar sublimation. J. Geophys. Res., 108(E4), 5031. (10.1029/2002JE001878.)
Pfeffer, W.T. and Bretherton, C.S.. 1987. The effect of crevasses on the solar heating of a glacier surface. IAHS Publ. 170 (Symposium at Vancouver 1987 – The Physical Basis of Ice Sheet Modelling), 191–205.
Raymond, M.J. and Gudmundsson, G.H.. 2005. On the relationship between surface and basal properties on glaciers, ice sheets, and ice streams. J. Geophys. Res., 110(B8), B08411. (10.1029/2005JB003681.)
Van As, D. and 6 others. 2010. Climatology and ablation at the South Greenland ice sheet margin from automatic weather station observations. Cryos. Discuss., 3(1), 117–158.
Van den Broeke, M., Smeets, P., Ettema, J. and Munneke, P.K.. 2008. Surface radiation balance in the ablation zone of the west Greenland ice sheet. J. Geophys. Res., 113(D13), D13105. (10.1029/2007JD009283.)
Van der Veen, C.J., Ahn, Y., Csatho, B.M., Mosley-Thompson, E. and Krabill, W.B.. 2009. Surface roughness over the northern half of theGreenland Ice Sheet fromairborne laser altimetry. J. Geophys. Res., 114(F1), F01001. (10.1029/2008JF001067.)
Walraven, R. 1978. Calculating the position of the Sun. Sol. Energy, 20(5), 393–397.
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Annals of Glaciology
  • ISSN: 0260-3055
  • EISSN: 1727-5644
  • URL: /core/journals/annals-of-glaciology
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