Filters








14 Hits in 5.0 sec

An adaptive Newton multigrid method for a model of marine ice sheets

Guillaume Jouvet, Carsten Gräser
2013 Journal of Computational Physics  
In this paper, we consider a model for the time evolution of three-dimensional marine ice sheets.  ...  To overcome such difficulty, the second approach considers a unified model for the ice sheet and for the ice shelf with an implicit description of the GL through the flotation criterion.  ...  Acknowledgements The authors thank Ralf Kornhuber for his support, Ed Bueler for helpful discussions and Maria Baden for English proofreading.  ... 
doi:10.1016/j.jcp.2013.06.032 fatcat:svbv2jlorfgbvocgjxupekgxxm

Adaptive mesh, finite volume modeling of marine ice sheets

Stephen L. Cornford, Daniel F. Martin, Daniel T. Graves, Douglas F. Ranken, Anne M. Le Brocq, Rupert M. Gladstone, Antony J. Payne, Esmond G. Ng, William H. Lipscomb
2013 Journal of Computational Physics  
We implement a blockstructured finite volume method with adaptive mesh refinement (AMR) for three dimensional ice sheets, which allows us to discretize a narrow region around the grounding line at high  ...  Continental scale marine ice sheets such as the present day West Antarctic Ice Sheet are strongly affected by highly localized features, presenting a challenge to numerical models.  ...  Originally, this model was derived for geometries which do not vary in y but adapting it to a three-dimensional ice sheet is straightforward.  ... 
doi:10.1016/j.jcp.2012.08.037 fatcat:fw5wtn6o5zgerd5wiqp4hlgaiq

Scalable and efficient algorithms for the propagation of uncertainty from data through inference to prediction for large-scale problems, with application to flow of the Antarctic ice sheet

Tobin Isaac, Noemi Petra, Georg Stadler, Omar Ghattas
2015 Journal of Computational Physics  
We present efficient and scalable algorithms for this end-to-end, data-to-prediction process under the Gaussian approximation and in the context of modeling the flow of the Antarctic ice sheet and its  ...  The ice is modeled as a viscous, incompressible, creeping, shear-thinning fluid.  ...  In each of these outer Newton iterations, the nonlinear forward Stokes problem has to be solved, for which we use an (inner) Newton method.  ... 
doi:10.1016/j.jcp.2015.04.047 fatcat:fpshnibcz5curhq6wtmznqc7vm

Implementation and performance of adaptive mesh refinement in the Ice Sheet System Model (ISSM v4.14)

Thiago Dias dos Santos, Mathieu Morlighem, Hélène Seroussi, Philippe Remy Bernard Devloo, Jefferson Cardia Simões
2019 Geoscientific Model Development  
The evolution of the grounding line indeed plays a major role in ice sheet dynamics, as it is a fundamental control on marine ice sheet stability.  ...  Accurate projections of the evolution of ice sheets in a changing climate require a fine mesh/grid resolution in ice sheet models to correctly capture fundamental physical processes, such as the evolution  ...  , Brazil, PhD scholarship no. 140186/2015-8 -and at the University of California, Irvine, under a contract with the National Aeronautics and Space Administration (NASA) Cryospheric Sciences Program (no  ... 
doi:10.5194/gmd-12-215-2019 fatcat:lwjb2katbbbsxoy3hf4ubvzlh4

Implementation and Performance of Adaptive Mesh Refinement in the Ice Sheet System Model (ISSM v4.14)

Thiago Dias dos Santos, Mathieu Morlighem, Hélène Seroussi, Philippe Remy Bernard Devloo, Jefferson Cardia Simões
2018 Geoscientific Model Development Discussions  
The evolution of the grounding line indeed plays a major role in ice sheet dynamics, as it is a fundamental control on marine ice sheet stability.  ...  </strong> Accurate projections of the evolution of ice sheets in a changing climate require a fine mesh/grid resolution to correctly capture fundamental physical processes, such as the evolution of the  ...  Jouvet and Gräser (2013) combined the Shallow Ice Approximation and the Shallow Shelf Approximation in an AMR numerical scheme involving a truncated Newton multigrid and finite volume method.  ... 
doi:10.5194/gmd-2018-194 fatcat:fpuj4vvyxjf4njysbry5dbmfiu

icepack: a new glacier flow modeling package in Python, version 1.0

Daniel R. Shapero, Jessica A. Badgeley, Andrew O. Hoffman, Ian R. Joughin
2021 Geoscientific Model Development  
We introduce a new software package called "icepack" for modeling the flow of glaciers and ice sheets.  ...  Finally, icepack includes a Gauss–Newton solver for inverse problems that runs substantially faster than the Broyden–Fletcher–Goldfarb–Shanno (BFGS) method often used in the glaciological literature.  ...  We would like to thank the Firedrake development team for their support and for many helpful discussions. Financial support.  ... 
doi:10.5194/gmd-14-4593-2021 fatcat:sdw2qyvwdrcl5pyg7v4zdnkcqi

Theoretical Developments in Electromagnetic Induction Geophysics with Selected Applications in the Near Surface

Mark E. Everett
2011 Surveys in geophysics  
This is a difficult task since papers describing electromagnetic induction methods are widely dispersed throughout the scientific literature.  ...  An attempt is made here to bring together and describe some of the most notable advances.  ...  This paper was written while I was on sabbatical leave from Texas A&M as a visiting professor at ETH, Zurich.  ... 
doi:10.1007/s10712-011-9138-y fatcat:v6t7a7k7dnecjfzp32x7lgjzcu

Meshless techniques for anisotropic diffusion

Annamaria Mazzia, Giorgio Pini, Flavio Sartoretto
2014 Applied Mathematics and Computation  
The latter would allow better use of parallel computers, since time-stepping is essentially a serial process. Moreover, it would be good for the methods to be of high order accuracy.  ...  A good numerical method would be locally mass conservative, produce no or minimal over/under-shoots, produce minimal numerical diffusion, and require no CFL time-step limit for stability.  ...  We show how to solve the equations using a global implicit approach in an efficient way, and we present the derived computational results.  ... 
doi:10.1016/j.amc.2014.03.032 fatcat:c527226gyfgbffnq4p67qxd7wi

Surface velocity and mass balance of Livingston Island ice cap, Antarctica

B. Osmanoglu, F. J. Navarro, R. Hock, M. Braun, M. I. Corcuera
2014 The Cryosphere  
</strong> The mass budget of the ice caps surrounding the Antarctica Peninsula and, in particular, the partitioning of its main components are poorly known.  ...  Islands archipelago, and analyse variations in surface velocity for the period 2007–2011.  ...  for data provision.  ... 
doi:10.5194/tc-8-1807-2014 fatcat:uuuqrgdzo5dnxksuqysbegpjga

Toward virtual biopsy through an all fiber optic ultrasonic miniaturized transducer: a proposal

A. Acquafresca, E. Biagi, L. Masotti, D. Menichelli
2003 IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control  
........Method of moments ........Mode matching methods ........Multigrid methods ........Newton method ........Numerical simulation ........Numerical stability ........Relaxation methods ........Sparse  ...  ............Metadata ........Deformable models ........Digital elevation models ........Emulation ........Graphical models ........Green&apos;s function methods ........Hidden Markov models ........Input  ... 
doi:10.1109/tuffc.2003.1244749 fatcat:l3jre4etsvcqzfyz2jqggji3gy

Large-scale dark matter simulations [article]

Raul E. Angulo, Oliver Hahn
2021 arXiv   pre-print
We finalise with a recount of state-of-the-art large-scale simulations and conclude with an outlook for the next decade.  ...  A key aspect of cosmological simulations is the connection to cosmological observables, we discuss various techniques in this regard: structure finding, galaxy formation and baryonic modelling, the creation  ...  Acknowledgements We would like to thank the editor, Thorsten Naab, for his invitation to write this article and his enormous patience during the process. We would also like to thank Alexandre Barreira  ... 
arXiv:2112.05165v1 fatcat:y462ymcryzhktnlefpkl25wnm4

Forty-First Annual Meeting March 2–6, 1997 Ernest N. Morial Convention Center New Orleans, Louisiana

1997 Biophysical Journal  
A mechanism of these phase transitions and the effect of the substitution of H'O by 1E0is proposed and discussed; an interaction energy between the surface segments of DPPC-MLV and solvents, may be important  ...  Phospholipid bilayers and monolayers composed of 18:0, 18:1 PC/18:0, 22:6 PC with differing amounts of cholesterol are used as models for biological membranes.  ...  By S.Korolev) MULTIGRID BOUNDARY ELEMENT METHOD FOR BIOMOLECULAR ELECTROSTATICS ((Y.N.Vorobjev and JanHermans)) UNC, Chapel Hill, NC 27599-7260, vorobjevOfemto.med.unc.edu A Fast Adaptive Multigrid Boundary  ... 
doi:10.1016/s0006-3495(97)78735-6 fatcat:fwfbe5dox5hunpzqz2y2qfckwi

79. Jahrestagung Deutsche Geophysikalische Gesellschaft. 04.-07. März 2019 in Braunschweig. Abstracts und Autorenverzeichnis

Deutsche Geophysikalische Gesellschaft
2019
In this study, a finite volume code using a multigrid scheme is the basis of an implemented adaptive mesh algorithm which considers differences in temperature, chemical composition or velocity to adapt  ...  Furthermore, we found that the Antarctic ice sheets are located too far to the south to induce significant RFB on a postglacial time scale.  ...  and monitoring of in-situ remediation of chlorinated hydrocarbon contamination using an interdisciplinary approach and geophysical methods, such as DCIP (direct current induced polarisation) to investigate  ... 
doi:10.2312/dgg79 fatcat:563ocnmvdfegxeryz62pncganm

73. Jahrestagung der Deutschen Geophysikalischen Gesellschaft : 4.–7. März 2013 in Leipzig [article]

Deutsche Geophysikalische Gesellschaft
2013
Acknowledgments: This work was funded by the Deutsche Forschungsgemeinschaft (DFG) and the German Federal Ministry for the Environment (BMU).  ...  Acknowledgements The AIDA project is part of the GEOTECHNOLOGIEN program and is funded by the Federal Ministry of Education and Research (BMBF, grant no. 03G0735). Acknowledgements  ...  A potential candidate for an appropriate rover is the IceMole which is a melting probe combined with an ice screw for forward thrust.  ... 
doi:10.2312/dgg73 fatcat:wx2hmkf5cnbjffoyqwyrfiyye4