TC The Cryosphere TC The Cryosphere 1994-0424 Copernicus Publications Göttingen, Germany 10.5194/tc-9-217-2015 Enthalpy benchmark experiments for numerical ice sheet models Kleiner T. https://orcid.org/0000-0001-7825-5765 1 Rückamp M. https://orcid.org/0000-0003-2512-7238 1 Bondzio J. H. 1 Humbert A. https://orcid.org/0000-0002-0244-8760 1 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Alten Hafen 26, 27568 Bremerhaven, Germany 06 02 2015 9 1 217 228 Copyright: © 2015 T. Kleiner et al. 2015 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://tc.copernicus.org/articles/9/217/2015/tc-9-217-2015.html The full text article is available as a PDF file from https://tc.copernicus.org/articles/9/217/2015/tc-9-217-2015.pdf

We present benchmark experiments to test the implementation of enthalpy and the corresponding boundary conditions in numerical ice sheet models. Since we impose several assumptions on the experiment design, analytical solutions can be formulated for the proposed numerical experiments. The first experiment tests the functionality of the boundary condition scheme and the basal melt rate calculation during transient simulations. The second experiment addresses the steady-state enthalpy profile and the resulting position of the cold–temperate transition surface (CTS). For both experiments we assume ice flow in a parallel-sided slab decoupled from the thermal regime. <br><br> We compare simulation results achieved by three different ice flow-models with these analytical solutions. The models agree well to the analytical solutions, if the change in conductivity between cold and temperate ice is properly considered in the model. In particular, the enthalpy gradient on the cold side of the CTS goes to zero in the limit of vanishing temperate-ice conductivity, as required from the physical jump conditions at the CTS.

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