Numerical ice sheet modeling : Forward and inverse problems
Ice sheets have strong influence on the climate system. Numerical simulation provides a mathematical tool to study the ice dynamics in the past and to predict their contribution to climate change in the future. Large scale ice sheets behave as incompressible non-Newtonian fluid. The evolution of ice...
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Uppsala universitet, Avdelningen för beräkningsvetenskap
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ftuppsalauniv:oai:DiVA.org:uu-392268 2023-05-15T16:39:48+02:00 Numerical ice sheet modeling : Forward and inverse problems Cheng, Gong 2019 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392268 eng eng Uppsala universitet, Avdelningen för beräkningsvetenskap Uppsala universitet, Numerisk analys Uppsala Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1849 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392268 urn:isbn:978-91-513-0738-1 info:eu-repo/semantics/openAccess ice sheet modeling finite element method grounding line migration inverse problems adjoint method Computational Mathematics Beräkningsmatematik Geosciences Multidisciplinary Multidisciplinär geovetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2019 ftuppsalauniv 2023-02-23T21:50:58Z Ice sheets have strong influence on the climate system. Numerical simulation provides a mathematical tool to study the ice dynamics in the past and to predict their contribution to climate change in the future. Large scale ice sheets behave as incompressible non-Newtonian fluid. The evolution of ice sheet is governed by the conservation laws of mass, momentum and energy, which is formulated as a system of partial differential equations. Improving the efficiency of numerical ice sheet modeling is always a desirable feature since many of the applications have large domain and aim for long time span. With such a goal, the first part of this thesis focuses on developing efficient and accurate numerical methods for ice sheet simulation. A large variety of physical processes are involved in ice dynamics, which are described by physical laws with parameters measured from experiments and field work. These parameters are considered as the inputs of the ice sheet simulations. In certain circumstances, some parameters are unavailable or can not be measured directly. Therefore, the second part of this thesis is devoted to reveal these physical parameters by solving inverse problems. In the first part, improvements of temporal and spatial discretization methods and a sub-grid boundary treatment are purposed. We developed an adaptive time stepping method in Paper I to automatically adjust the time steps based on stability and accuracy criteria. We introduced an anisotropic Radial Basis Function method for the spatial discretization of continental scale ice sheet simulations in Paper II. We designed a sub-grid method for solving grounding line migration problem with Stokes equations in Paper VI. The second part of the thesis consists of analysis and numerical experiments on inverse problems. In Paper IV and V, we conducted sensitivity analysis and numerical examples of the inversion on time dependent ice sheet simulations. In Paper III, we solved an inverse problem for the thermal conductivity of firn pack at Lomonosovfonna, ... Doctoral or Postdoctoral Thesis Ice Sheet Uppsala University: Publications (DiVA) Lomonosovfonna ENVELOPE(17.663,17.663,78.774,78.774) |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
ice sheet modeling finite element method grounding line migration inverse problems adjoint method Computational Mathematics Beräkningsmatematik Geosciences Multidisciplinary Multidisciplinär geovetenskap |
spellingShingle |
ice sheet modeling finite element method grounding line migration inverse problems adjoint method Computational Mathematics Beräkningsmatematik Geosciences Multidisciplinary Multidisciplinär geovetenskap Cheng, Gong Numerical ice sheet modeling : Forward and inverse problems |
topic_facet |
ice sheet modeling finite element method grounding line migration inverse problems adjoint method Computational Mathematics Beräkningsmatematik Geosciences Multidisciplinary Multidisciplinär geovetenskap |
description |
Ice sheets have strong influence on the climate system. Numerical simulation provides a mathematical tool to study the ice dynamics in the past and to predict their contribution to climate change in the future. Large scale ice sheets behave as incompressible non-Newtonian fluid. The evolution of ice sheet is governed by the conservation laws of mass, momentum and energy, which is formulated as a system of partial differential equations. Improving the efficiency of numerical ice sheet modeling is always a desirable feature since many of the applications have large domain and aim for long time span. With such a goal, the first part of this thesis focuses on developing efficient and accurate numerical methods for ice sheet simulation. A large variety of physical processes are involved in ice dynamics, which are described by physical laws with parameters measured from experiments and field work. These parameters are considered as the inputs of the ice sheet simulations. In certain circumstances, some parameters are unavailable or can not be measured directly. Therefore, the second part of this thesis is devoted to reveal these physical parameters by solving inverse problems. In the first part, improvements of temporal and spatial discretization methods and a sub-grid boundary treatment are purposed. We developed an adaptive time stepping method in Paper I to automatically adjust the time steps based on stability and accuracy criteria. We introduced an anisotropic Radial Basis Function method for the spatial discretization of continental scale ice sheet simulations in Paper II. We designed a sub-grid method for solving grounding line migration problem with Stokes equations in Paper VI. The second part of the thesis consists of analysis and numerical experiments on inverse problems. In Paper IV and V, we conducted sensitivity analysis and numerical examples of the inversion on time dependent ice sheet simulations. In Paper III, we solved an inverse problem for the thermal conductivity of firn pack at Lomonosovfonna, ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Cheng, Gong |
author_facet |
Cheng, Gong |
author_sort |
Cheng, Gong |
title |
Numerical ice sheet modeling : Forward and inverse problems |
title_short |
Numerical ice sheet modeling : Forward and inverse problems |
title_full |
Numerical ice sheet modeling : Forward and inverse problems |
title_fullStr |
Numerical ice sheet modeling : Forward and inverse problems |
title_full_unstemmed |
Numerical ice sheet modeling : Forward and inverse problems |
title_sort |
numerical ice sheet modeling : forward and inverse problems |
publisher |
Uppsala universitet, Avdelningen för beräkningsvetenskap |
publishDate |
2019 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392268 |
long_lat |
ENVELOPE(17.663,17.663,78.774,78.774) |
geographic |
Lomonosovfonna |
geographic_facet |
Lomonosovfonna |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, 1651-6214 1849 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-392268 urn:isbn:978-91-513-0738-1 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766030135558930432 |