Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies

Sea ice is an essential component of the climate system because it modulates the exchange of energy between the ocean and the atmosphere. Under stress from wind and ocean currents, sea ice deforms constantly. Sea ice deformation takes the shape of narrow lines, the Linear Kinematic Features (LKFs)....

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Main Author: Ringeisen, Damien
Format: Thesis
Language:unknown
Published: 2020
Subjects:
Online Access:https://epic.awi.de/id/eprint/53578/
https://doi.org/10.26092/elib/380
https://hdl.handle.net/10013/epic.9fb0a3ff-1d40-417a-b82b-c910dc11e162
id ftawi:oai:epic.awi.de:53578
record_format openpolar
spelling ftawi:oai:epic.awi.de:53578 2024-09-15T18:34:10+00:00 Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies Ringeisen, Damien 2020-09-04 https://epic.awi.de/id/eprint/53578/ https://doi.org/10.26092/elib/380 https://hdl.handle.net/10013/epic.9fb0a3ff-1d40-417a-b82b-c910dc11e162 unknown Ringeisen, D. orcid:0000-0002-8436-6928 (2020) Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies PhD thesis, Universität Bremen. doi:10.26092/elib/380 <https://doi.org/10.26092/elib%2F380> , hdl:10013/epic.9fb0a3ff-1d40-417a-b82b-c910dc11e162 EPIC3 Thesis notRev 2020 ftawi https://doi.org/10.26092/elib/380 2024-06-24T04:26:11Z Sea ice is an essential component of the climate system because it modulates the exchange of energy between the ocean and the atmosphere. Under stress from wind and ocean currents, sea ice deforms constantly. Sea ice deformation takes the shape of narrow lines, the Linear Kinematic Features (LKFs). LKFs influence the heat transfer, mass balance, and sea ice dynamics, so LKFs should be accurately represented in high-resolution climate models. Sea ice is commonly modeled using viscous-plastic (VP) rheologies defined by a yield curve and a flow rule. Recent work showed that VP sea ice models explicitly create LKFs but overestimate their intersection angles. This thesis aims to investigate the link between the angles of fracture in sea ice models and the parametrization of the sea ice internal stresses using idealized compression experiments. Three questions are addressed: Which parameters of the VP rheologies influence the fracture angle? Which theoretical framework explains this influence? Which rheologies should be used to simulate intersection angles at the observed range? With the commonly used standard VP rheology with an elliptical yield curve and a normal flow rule, the fracture angles are linked to the yield curve's elliptical shape. Because of this shape, this rheology cannot create sea ice fracture angles more acute than 30 degrees in uniaxial compression, even by changing the aspect of the ellipse. The classical coulombic theory predicts the angle of fracture accurately when adapted to the context of sea ice modeling. A new rheology with an elliptical yield curve and a non-normal flow rule shows that fracture angles are also sensitive to the orientation of the flow rule. Using this new rheology allows creating fracture angles as low as 22 degrees in uniaxial compression. A theory based on the angle of dilatancy and observations of granular materials predicts precisely the simulated angles. Alternative rheologies can create fracture angles lower than 30 degrees. With Mohr--Coulomb yield curves, fracture ... Thesis Sea ice Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
institution Open Polar
collection Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center)
op_collection_id ftawi
language unknown
description Sea ice is an essential component of the climate system because it modulates the exchange of energy between the ocean and the atmosphere. Under stress from wind and ocean currents, sea ice deforms constantly. Sea ice deformation takes the shape of narrow lines, the Linear Kinematic Features (LKFs). LKFs influence the heat transfer, mass balance, and sea ice dynamics, so LKFs should be accurately represented in high-resolution climate models. Sea ice is commonly modeled using viscous-plastic (VP) rheologies defined by a yield curve and a flow rule. Recent work showed that VP sea ice models explicitly create LKFs but overestimate their intersection angles. This thesis aims to investigate the link between the angles of fracture in sea ice models and the parametrization of the sea ice internal stresses using idealized compression experiments. Three questions are addressed: Which parameters of the VP rheologies influence the fracture angle? Which theoretical framework explains this influence? Which rheologies should be used to simulate intersection angles at the observed range? With the commonly used standard VP rheology with an elliptical yield curve and a normal flow rule, the fracture angles are linked to the yield curve's elliptical shape. Because of this shape, this rheology cannot create sea ice fracture angles more acute than 30 degrees in uniaxial compression, even by changing the aspect of the ellipse. The classical coulombic theory predicts the angle of fracture accurately when adapted to the context of sea ice modeling. A new rheology with an elliptical yield curve and a non-normal flow rule shows that fracture angles are also sensitive to the orientation of the flow rule. Using this new rheology allows creating fracture angles as low as 22 degrees in uniaxial compression. A theory based on the angle of dilatancy and observations of granular materials predicts precisely the simulated angles. Alternative rheologies can create fracture angles lower than 30 degrees. With Mohr--Coulomb yield curves, fracture ...
format Thesis
author Ringeisen, Damien
spellingShingle Ringeisen, Damien
Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
author_facet Ringeisen, Damien
author_sort Ringeisen, Damien
title Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
title_short Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
title_full Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
title_fullStr Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
title_full_unstemmed Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies
title_sort fracture angles in numerical simulations of sea ice with viscous-plastic rheologies
publishDate 2020
url https://epic.awi.de/id/eprint/53578/
https://doi.org/10.26092/elib/380
https://hdl.handle.net/10013/epic.9fb0a3ff-1d40-417a-b82b-c910dc11e162
genre Sea ice
genre_facet Sea ice
op_source EPIC3
op_relation Ringeisen, D. orcid:0000-0002-8436-6928 (2020) Fracture Angles in Numerical Simulations of Sea Ice with Viscous-Plastic Rheologies PhD thesis, Universität Bremen. doi:10.26092/elib/380 <https://doi.org/10.26092/elib%2F380> , hdl:10013/epic.9fb0a3ff-1d40-417a-b82b-c910dc11e162
op_doi https://doi.org/10.26092/elib/380
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