Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-12-01T01:07:26.576Z Has data issue: false hasContentIssue false

A multilayer ice-flow model generalising the shallow shelf approximation

Published online by Cambridge University Press:  22 December 2014

Abstract

A new hybrid model for the dynamics of glaciers, ice sheets and ice shelves is introduced. In this ‘multilayer’ model the domain of ice consists of a pile of thin layers, which can spread out, contract and slide over each other such that the two most relevant types of stresses are accounted for: membrane and vertical shear. Assuming the horizontal velocity field to be vertically piecewise constant in each layer, the model is derived from local depth integrations of the hydrostatic approximation of the Stokes equations. These integrations give rise to interlayer tractions, which can be redefined at zeroth order in the interlayer surface slope by keeping the vertical shear stress components. Furthermore, if the layers are chosen such that they are aligned with the streamlines, then second-order accurate interlayer tractions can replace zeroth-order ones. The final model consists of a tridiagonal system of two-dimensional nonlinear elliptic equations, the size of this system being equal to the number of layers. When running the model for prognostic flowline ISMIP-HOM benchmark experiments, the multilayer solutions show good agreement with the higher-order solutions if no severe depression occurs in the bedrock. As an alternative to three-dimensional models, the multilayer approach offers to glacier and ice sheet modellers a way of upgrading the commonly used shallow shelf approximation model into a mechanically complete but mathematically two-dimensional model.

Type
Papers
Copyright
© 2014 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ahlkrona, J., Kirchner, N. & Lötstedt, P. 2013 A numerical study of scaling relations for non-Newtonian thin-film flows with applications in ice sheet modelling. Q. J. Mech. Appl. Maths 66 (4), 417435.CrossRefGoogle Scholar
Audusse, E., Bristeau, M.-O., Perthame, B. & Sainte-Marie, J. 2011 A multilayer saint-venant system with mass exchanges for shallow water flows. Derivation and numerical validation. ESAIM Math. Model. Numer. Anal. 45, 169200.Google Scholar
Baral, D. R., Hutter, K. & Greve, R. 2001 Asymptotic theories of large-scale motion, temperature and moisture distribution in land-based polythermal ice sheets: a critical review and new developments. Appl. Mech. Rev. 54, 215256.Google Scholar
Blatter, H. 1995 Velocity and stress fields in grounded glaciers: a simple algorithm for including deviatoric stress gradients. J. Glaciol. 41 (138), 333344.CrossRefGoogle Scholar
Brown, J., Smith, B. F. & Ahmadia, A. 2013 Achieving textbook multigrid efficiency for hydrostatic ice sheet flow. SIAM J. Sci. Comput. 35, 83598375.Google Scholar
Bueler, E. & Brown, J. 2009 Shallow shelf approximation as a ‘sliding law’ in a thermomechanically coupled ice sheet model. J. Geophys. Res. Earth Surf. 114, F3.CrossRefGoogle Scholar
Cornford, S., Martin, D. F., Graves, D. T., Ranken, D. F., Brocq Le, A. M., Gladstone, R. M., Payne, A. J., Ng, E. G. & Lipscomb, W. H. 2013 Adaptive mesh, finite volume modeling of marine ice sheets. J. Comput. Phys. 529549.CrossRefGoogle Scholar
Egholm, D. L., Knudsen, M. F., Clark, C. D. & Lesemann, J. E. 2011 Modeling the flow of glaciers in steep terrains: the integrated second-order shallow ice approximation (ISOSIA). J. Geophys. Res. Earth Surf. 116, F2.Google Scholar
Fowler, A. C. & Larson, D. A. 1978 On the flow of polythermal glaciers. I. Model and preliminary analysis. Proc. R. Soc. Lond. A 363 (1713), 217242.Google Scholar
Gagliardini, O. & Zwinger, T. 2008 The ISMIP-HOM benchmark experiments performed using the finite-element code Elmer. Cryosphere Discuss 2, 75109.Google Scholar
Glen, J. W. 1953 Rate of flow of polycrystalline ice. Nature 172, 721722.CrossRefGoogle Scholar
Goldberg, D. N. 2011 A variationally derived, depth-integrated approximation to a higher-order glaciological flow model. J. Glaciol. 57 (201), 157170.CrossRefGoogle Scholar
Greve, R. & Blatter, H. 2009 Dynamics of Ice Sheets and Glaciers. Springer.Google Scholar
Hindmarsh, R. C. A. 2004 A numerical comparison of approximations to the Stokes equations used in ice sheet and glacier modeling. J. Geophys. Res. Earth Surf. 109, F1.CrossRefGoogle Scholar
Hutter, K. 1983 Theoretical Glaciology. Reidel.Google Scholar
Jouvet, G. & Gräser, C. 2013 An adaptive Newton multigrid method for a model of marine ice sheets. J. Comput. Phys. 252 (0), 419437.Google Scholar
MacAyeal, D. R. 1989 Large-scale ice flow over a viscous basal sediment: theory and application to ice stream B, Antarctica. J. Geophys. Res. Solid Earth 94 (B4), 40714087.Google Scholar
Morland, L. W. 1987 Unconfined ice-shelf flow. In Glaciology and Quaternary Geology (ed. Veen, C. J. & Oerlemans, J.), vol. 4, pp. 99116. Springer.Google Scholar
Paterson, W. S. B. 1994 The Physics of Glaciers, 3rd edn. Pergamon.Google Scholar
Pattyn, F. 2003 A new three-dimensional higher-order thermomechanical ice sheet model: basic sensitivity, ice stream development, and ice flow across subglacial lakes. J. Geophys. Res. 106, B8.Google Scholar
Pattyn, F., Perichon, L., Aschwanden, A., Breuer, B., de Smedt, B., Gagliardini, O., Gudmundsson, G. H., Hindmarsh, R. C. A., Hubbard, A., Johnson, J. V., Kleiner, T., Konovalov, Y., Martin, C., Payne, A. J., Pollard, D., Price, S., Rückamp, M., Saito, F., Souček, O., Sugiyama, S. & Zwinger, T. 2008 Benchmark experiments for higher-order and full-Stokes ice sheet models (ISMIP-HOM). Cryosphere 2 (2), 95108.Google Scholar
Pattyn, F., Perichon, L., Durand, G., Favier, L., Gagliardini, O., Hindmarsh, R., Zwinger, T., Albrecht, T., Cornford, S. L., Docquier, D., Fürst, J., Goldberg, D., Gudmundsson, G., Humbert, A., Hütten, M., Huybrechts, P., Jouvet, G., Kleiner, T., Larour, E., Martin, D., Morlighem, M., Payne, A., Pollard, D., Rückamp, M., Rybak, O., Seroussi, H., Thoma, M. & Wilkens, N. 2013 Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison. J. Glaciol. 59 (215), 410422.CrossRefGoogle Scholar
Pollard, D. & Deconto, R. M. 2009 A Coupled Ice-Sheet/Ice-Shelf/Sediment Model Applied to a Marine-Margin Flowline: Forced and Unforced Variations, pp. 3752. Blackwell.Google Scholar
Schoof, C. 2006 A variational approach to ice stream flow. J. Fluid Mech. 556, 227251.CrossRefGoogle Scholar
Schoof, C. & Hindmarsh, R. C. A. 2010 Thin-film flows with wall slip: an asymptotic analysis of higher order glacier flow models. Q. J. Mech. Appl. Maths 63 (1), 73114.Google Scholar
Vaughan, D. G. & Arthern, R. 2007 Why is it hard to predict the future of ice sheets? Science 315 (5818), 15031504.Google Scholar
Weis, M., Greve, R. & Hutter, K. 1999 Theory of shallow ice shelves. Contin. Mech. Thermodyn. 11 (1), 1550.CrossRefGoogle Scholar
Winkelmann, R., Martin, M. A., Haseloff, M., Albrecht, T., Bueler, E., Khroulev, C. & Levermann, A. 2011 The Potsdam parallel ice sheet model (PISM-PIK)—part 1: model description. Cryosphere 5 (3), 715726.Google Scholar