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Main Authors: Hötten, David, Niebsch, Jenny, Ramlau, Ronny, Zulehner, Walter
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2504.02475
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author Hötten, David
Niebsch, Jenny
Ramlau, Ronny
Zulehner, Walter
author_facet Hötten, David
Niebsch, Jenny
Ramlau, Ronny
Zulehner, Walter
contents We consider the problem of heat conduction with phase change, that is essential for permafrost modeling in Land Surface Models and Dynamic Global Vegetation Models. These models require minimal computational effort and an extremely robust solver for large-scale, long-term simulations. The weak enthalpy formulation of the Stefan problem is used as the mathematical model and a finite element method is employed for the discretization. Leveraging the piecewise affine structure of the nonlinear time-stepping equation system, we demonstrate that this system has a unique solution and provide a solver that is guaranteed to find this solution in a finite number of steps from any initial guess. Comparisons with the Neumann analytical solution and tests in the Lund-Potsdam-Jena managed Land vegetation model reveal that the new method does not introduce significantly higher computational costs than the widely used DECP method while providing greater accuracy. In particular, it avoids a known nonphysical artifact in the solution.
format Preprint
id arxiv_https___arxiv_org_abs_2504_02475
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Heat Conduction with Phase Change in Permafrost Modules of Vegetation Models
Hötten, David
Niebsch, Jenny
Ramlau, Ronny
Zulehner, Walter
Numerical Analysis
65M60, 65M22
We consider the problem of heat conduction with phase change, that is essential for permafrost modeling in Land Surface Models and Dynamic Global Vegetation Models. These models require minimal computational effort and an extremely robust solver for large-scale, long-term simulations. The weak enthalpy formulation of the Stefan problem is used as the mathematical model and a finite element method is employed for the discretization. Leveraging the piecewise affine structure of the nonlinear time-stepping equation system, we demonstrate that this system has a unique solution and provide a solver that is guaranteed to find this solution in a finite number of steps from any initial guess. Comparisons with the Neumann analytical solution and tests in the Lund-Potsdam-Jena managed Land vegetation model reveal that the new method does not introduce significantly higher computational costs than the widely used DECP method while providing greater accuracy. In particular, it avoids a known nonphysical artifact in the solution.
title Heat Conduction with Phase Change in Permafrost Modules of Vegetation Models
topic Numerical Analysis
65M60, 65M22
url https://arxiv.org/abs/2504.02475