{"title":"冰隆的三维诊断性各向异性场建模","authors":"A. Clara J. Henry, Carlos Martín, Reinhard Drews","doi":"arxiv-2408.01069","DOIUrl":null,"url":null,"abstract":"Polar ice develops anisotropic crystal orientation fabrics under deformation,\nyet ice is most often modelled as an isotropic fluid. We present\nthree-dimensional simulations of the crystal orientation fabric of Derwael Ice\nRise including the surrounding ice shelf using a crystal orientation tensor\nevolution equation corresponding to a fixed velocity field. We use a\nsemi-Lagrangian numerical method that constrains the degree of crystal\norientation evolution to solve the equations in complex flow areas. We perform\nfour simulations based on previous studies, altering the rate of evolution of\nthe crystal anisotropy and its dependence on a combination of the strain rate\nand deviatoric stress tensors. We provide a framework for comparison with radar\nobservations of the anisotropy field, outlining areas where the assumption of\none vertical eigenvector may not hold and provide resulting errors in measured\neigenvalues. We recognise the areas of high horizontal divergence at the ends\nof the flow divide as important areas to make comparisons with observations.\nHere, poorly constrained model parameters result in the largest difference in\nfabric type. These results are important in the planning of future campaigns\nfor gathering data to constrain model parameters and as a link between\nobservations and computationally-efficient, simplified models of anisotropy.","PeriodicalId":501270,"journal":{"name":"arXiv - PHYS - Geophysics","volume":"58 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Modelling the three-dimensional, diagnostic anisotropy field of an ice rise\",\"authors\":\"A. Clara J. Henry, Carlos Martín, Reinhard Drews\",\"doi\":\"arxiv-2408.01069\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Polar ice develops anisotropic crystal orientation fabrics under deformation,\\nyet ice is most often modelled as an isotropic fluid. We present\\nthree-dimensional simulations of the crystal orientation fabric of Derwael Ice\\nRise including the surrounding ice shelf using a crystal orientation tensor\\nevolution equation corresponding to a fixed velocity field. We use a\\nsemi-Lagrangian numerical method that constrains the degree of crystal\\norientation evolution to solve the equations in complex flow areas. We perform\\nfour simulations based on previous studies, altering the rate of evolution of\\nthe crystal anisotropy and its dependence on a combination of the strain rate\\nand deviatoric stress tensors. We provide a framework for comparison with radar\\nobservations of the anisotropy field, outlining areas where the assumption of\\none vertical eigenvector may not hold and provide resulting errors in measured\\neigenvalues. We recognise the areas of high horizontal divergence at the ends\\nof the flow divide as important areas to make comparisons with observations.\\nHere, poorly constrained model parameters result in the largest difference in\\nfabric type. These results are important in the planning of future campaigns\\nfor gathering data to constrain model parameters and as a link between\\nobservations and computationally-efficient, simplified models of anisotropy.\",\"PeriodicalId\":501270,\"journal\":{\"name\":\"arXiv - PHYS - Geophysics\",\"volume\":\"58 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-08-02\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"arXiv - PHYS - Geophysics\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/arxiv-2408.01069\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Geophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2408.01069","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Modelling the three-dimensional, diagnostic anisotropy field of an ice rise
Polar ice develops anisotropic crystal orientation fabrics under deformation,
yet ice is most often modelled as an isotropic fluid. We present
three-dimensional simulations of the crystal orientation fabric of Derwael Ice
Rise including the surrounding ice shelf using a crystal orientation tensor
evolution equation corresponding to a fixed velocity field. We use a
semi-Lagrangian numerical method that constrains the degree of crystal
orientation evolution to solve the equations in complex flow areas. We perform
four simulations based on previous studies, altering the rate of evolution of
the crystal anisotropy and its dependence on a combination of the strain rate
and deviatoric stress tensors. We provide a framework for comparison with radar
observations of the anisotropy field, outlining areas where the assumption of
one vertical eigenvector may not hold and provide resulting errors in measured
eigenvalues. We recognise the areas of high horizontal divergence at the ends
of the flow divide as important areas to make comparisons with observations.
Here, poorly constrained model parameters result in the largest difference in
fabric type. These results are important in the planning of future campaigns
for gathering data to constrain model parameters and as a link between
observations and computationally-efficient, simplified models of anisotropy.