Ice Sheet Modeling at UAF

We develop and maintain the Parallel Ice Sheet Model (PISM). See pism.io for up-to-date information on the model.

WARNING: This page holds a mostly-historical list of people and presentations.

observed versus PISM-modeled surface velocity from 1km run

Observed (left; Joughin et al, 2010) and PISM-modeled (right;) surface speed for the Greenland ice sheet. From a 1km grid. Click on image to get 7Mb high res version.

modeled ice speed for Ross Ice Shelf, Antarctica

PISM-modeled (black arrows) versus observed (white arrows) ice-flow speed for Ross Ice Shelf, Antarctica. From 2.5km grid computation.

contents:

presentations
students
verification

People

Andy Aschwanden, Arctic Region Supercomputing Center and Geophysical Institute (GI), UAF
Ed Bueler, Dept. of Mathematics and Statistics and GI, UAF
Mark Fahnestock, Research Professor, GI, UAF
Regine Hock, Dept. of Geology and Geophysics and GI, UAF
Constantine Khroulev, scientific programmer (Research Professional), GI UAF
Martin Truffer, Dept. of Physics and GI, UAF

Former group members

Jed Brown, MS Mathematics 2006, UAF
Latrice Bowman, MS Mathematics 2003, UAF
Dani Dellagiustina, MS Computational Physics 2011, UAF
Marijke Habermann, PhD student in Geophysics, UAF
Craig Lingle, Professor emeritus of Geophysics, UAF
Will Mitchell, MS Mathematics 2012, UAF
David Maxwell, Dept. of Mathematics and Statistics, UAF

Parallel Ice Sheet Model (PISM):

Publications and technical reports:

All relevant publications by the group are listed here.

Presentations & Posters:

E. Bueler and P. Farrell, Fast solvers for partial differential equations subject to inequalities, Dept. of Mathematics and Statistics Colloquium, UAF, November 2023.

E. Bueler, Glacial flows, simulated faster, Indiana University Mathematical Seminar, June 2023.

E. Bueler, Making ice sheet models scale properly, Oxford University Mathematical Geoscience Seminar, February 2023.

E. Bueler and P. Farrell, Toward nonlinear multigrid for nonlinear and nonlocal variational inequalities, Oxford University Computational Mathematics and Applications Seminar, February 2023.

E. Bueler, Implicit multigrid methods for glacier geometry, Invited presentation at 2022 SIAM Annual meeting, Pittsburg, July 2022.

E. Bueler, Evolution of ice sheet geometry using Stokes dynamics, Invited presentation at 2021 SIAM Geosciences meeting, Milan, June 2021 (virtual).

E. Bueler, Stokes problems using Firedrake: A glacier and ice sheet tutorial, Glaciers Seminar, UAF, April 2021; see code collection at github.com/bueler/stokes-ice-tutorial

E. Bueler, Glacier complementarity: How to apply equations for where equations apply, Glaciers Seminar, UAF, November 2020.

E. Bueler, A practical view of the classical FEM (and some FEM software), Dept. of Mathematics and Statistics informal FEM Seminar, UAF, December 2018.

E. Bueler, Optimal solvers for partial differential equations, Dept. of Mathematics and Statistics Colloquium, UAF, November 2017.

E. Bueler, Implicit time-stepping for ice sheets, Invited presentation at 2017 SIAM Computational Science and Engineering meeting, Atlanta, March 2017.

E. Bueler, Fluid layers, climates, and weak formulations, (26 MB PDF) Dept. of Mathematics and Statistics Colloquium, UAF, April 2016.

E. Bueler, Computing glacier geometry in nonlinear complementarity problem form, (10 MB PDF) Invited presentation at 14th Copper Mountain Conference on Iterative Methods, March 21 2016.

E. Bueler, Free-boundary problems in models of the cryosphere, (20 MB PDF) Invited presentation at 2015 SIAM Geosciences meeting, Stanford, July 1 2015.

E. Bueler, Mathematical tools and obstacles in models of ice sheets, (11 MB PDF) Math Dept. Colloquium, University of Denver, May 2015.

E. Bueler, Free boundaries and conservation equations in ice sheet models, (7 MB PDF) Invited presentation at 2015 CESM Land Ice Working Group meeting, February 2015.

E. Bueler, Conservation in free-boundary fluid layer models, (7 MB, PDF) Invited presentation at 2014 AGU Fall Meeting, December 2014.

E. Bueler, Flowing ice sheets (with a bit of applied math), (36 MB, PDF) talk for OWU at IARC, UAF, May 2014.

E. Bueler, What is ... a variational inequality?, (3 MB, PDF) Dept. of Mathematics and Statistics Colloquium, UAF, January 2014.

A. Aschwanden, The need for hindcasting in ice sheet modeling, or why we can get the right answer for the wrong reason, (23 MB, PDF) VAW Seminar, ETH Zurich, October 2013.

A. Aschwanden, Using observations to validate ice sheet models, (41 MB, PDF). Earth and Space Sciences research presentation, Univ. Washington, April 2013.

A. Aschwanden, Understanding ice sheets through observations and models, (43 MB, PDF). Earth and Space Sciences Seminar, Univ. Washington, April 2013, and a simulation (10 MB, MP4) for this talk.

G. Adalgeirsdottir and A. Aschwanden, Are the simulated climatic and dynamic mass losses of the Greenland Ice Sheet decoupled during the next 100 years? (4 MB, PDF). Poster at EGU General Assembly, Vienna, Austria, April 2013.

A. Aschwanden, Why we model ice sheets, (60 MB, PDF). Institute for Geophysics research presentation, Univ. Texas, Austin, March 2013

A. Aschwanden, Why we need to model ice sheets, (43 MB, PDF). Dept. of Geosciences Seminar, Univ. Montana, Missoula, December 2012

A. Aschwanden and J. van Angelen, Greenland mass changes from 1960 to 2100: Hindcasting and forecasting with PISM and RACMO2/GR, (5 MB, PDF). Presentation at 2012 AGU Fall Meeting.

E. Bueler, Weak and shallow: New thinking about simulations of ice sheet flows (28 MB, PDF) Pacific Northwest Numerical Analysis Seminar, Boise State Univ., October 2012.

A. Aschwanden, The need for hindcasting in ice sheet modeling (10 MB, PDF) Pacific Northwest Glaciology Meeting, Seattle, October 2012.

E. Bueler, How ice sheets flow, and how to model it on a computer (21 MB, PDF) Geology & Geophysics Seminar, UAF, October 2012.

W. Mitchell, Geophysical Ice Flows: Analytical and Numerical Approaches (8 MB, PDF) MS Mathematics thesis defense and Dept. of Mathematics and Statistics Colloquium, UAF, July 2012.

E. Bueler, Better subglacial hydrology into PISM (8 MB, PDF) PresentationIGS Symposium on Glaciers and Ice Sheets in a Warming Climate, Fairbanks, June 2012.

E. Bueler, PISM (the Parallel Ice Sheet Model) Latest 0.5 release, and Where will this community take PISM? (12 MB, PDF) Presentation at the European PISM Workshop, Max Planck Institute for Meteorology, Hamburg, May 2012.

C. Khroulev, E. Bueler, and A. Aschwanden, PISM (Parallel Ice Sheet Model): Current status and future plans. (5 MB, PDF) Presentation at CESM Land Ice Working Group (LIWG) meeting, Boulder, February 2012.

A. Aschwanden, Utilizing NASA data products to improve ice sheet models, (5 MB, PDF). Presentation at PARCA meeting, January 2012.

A. Aschwanden and G. Adalgeirsdottir, Observation-based validation of ice sheet model initial conditions using realistic atmospheric forcing for Greenland, (62 MB, PDF). Presentation at 2011 AGU Fall Meeting.

D. DellaGiustina, A. Aschwanden, C. Khroulev , E. Bueler , and M. Truffer, Century-scale evolution of the Jakobshavn Isbrae with a high resolution regional model, (1 MB, PDF). Poster at 2011 AGU Fall Meeting.

E. Bueler, Greenland ice sheet flow computations: scaling-up to high spatial resolution and fast boundary processes, (36 MB,PDF). Presentation at Cray Users Group 2011 meeting, Fairbanks, May 2011.

E. Bueler, Should your ice sheet model conserve energy? Dept. of Mathematics and Statistics Colloquium, UAF, April 2011.

A. Aschwanden, Inferring Greenland's present state from models and observations: The key to the future. Geology & Geophysics Seminar, UAF, April 2011.

E. Bueler, A. Aschwanden, and H. Blatter, Enthalpy formulations for ice sheet modeling, and the role of basal melt rates, (1.4 MB,PDF). Seminar presentation, Centre for Ice and Climate, Niel Bohr Institute, Copenhagen, January 2011.

R. Hock, A. Aschwanden, J. Ettema, E. Bueler, C. Khroulev, D. DellaGiustina, M. van den Broeke, Improving degree-day melt modeling of the Greenland ice sheet in the Parallel Ice Sheet Model (PISM), (6.2 MB,PDF). Presentation at 2010 AGU Fall Meeting.

D. DellaGiustina, E. Bueler, A. Aschwanden, C. Khroulev, M. Truffer, R. Hock, Regional modeling of Greenland's outlet glaciers, (7.6 MB,PDF). Poster at 2010 AGU Fall Meeting.

A. Aschwanden and the SeaRISE community, Observational requirements to improve ice sheet models – the SeaRISE perspective, (13 MB,PDF). Presentation at 2010 AGU Fall Meeting.

D. Maxwell, Determination of ice stream bed strength via the incomplete Gauss-Newton method, (0.9 MB,PDF). Presentation at 2010 AGU Fall Meeting.

A. Aschwanden, C. Khroulev, and E. Bueler, The Parallel Ice Sheet Model as a flowline model, (2.4 MB,PDF). Poster at 2010 AGU Fall Meeting.

R. Hock, A. Aschwanden, J. Ettema, E. Bueler, C. Khroulev, and M. van den Broeke, Parameterizing Greenland’s surfacemass balance in the Parallel Ice Sheet Model (PISM), (8.9 MB,PDF). Presentation at IGS Symposium on Earth's Disappearing Ice, Byrd Polar Research Center, Columbus, Ohio, USA, August 2010.

A. Aschwanden, E. Bueler, and C. Khroulev, Evaluating the sensitivity of an ice sheet model to changes in bed elevation and inclusion of membrane stresses, (8.9 MB,PDF). Presentation at European Geosciences Union General Assembly, Vienna, Austria, May 2010.

E. Bueler, A. Aschwanden, D. Della Guistina, R. Hock, C. Khroulev, D. Maxwell, and M. Truffer, PISM, a Parallel Ice Sheet Model (stable0.3 release), (3.6MB,PDF). Poster at European Geosciences Union General Assembly, Vienna, Austria, May 2010.

E. Bueler, C. Khroulev, A. Aschwanden, I. Joughin, and B. Smith, Modeled and observed fast flow in the Greenland ice sheet, (1.9MB,PDF). Poster at European Geosciences Union General Assembly, Vienna, Austria, May 2010.

E. Bueler, PISM, a Parallel Ice Sheet Model, (2.6MB,PDF). Presentation at ARSC Computational Science Symposium, February 2010.

E. Bueler, C. Khroulev, and A. Aschwanden, Verification, validation, and basal strength inmodels for the present state of ice sheets, (2.6MB,PDF). Presentation at CCSM Land Ice Working Group, NCAR, Boulder, CO, February 2010.

A. Aschwanden, C. Khroulev, and E. Bueler, SeaRISE Greenland--On "spin-up" procedures, (1.4MB, PDF). Poster at 2009 AGU Fall Meeting.

E. Bueler, Numerical modelling of ice sheetsand ice shelves(5MB, PDF; also see complete web page here), a short course given at Karthaus 2009 Summer School on Ice Sheets and Glaciers in the Climate System, September, 2009.

E. Bueler, C. Khroulev, A. Aschwanden, and I. Joughin, Modeled and observed fast flow in the Greenland ice sheet , (6 MB, PDF). Presentation at IGS International Symposium on Glaciology in the International Polar Year, Newcastle, UK, July 2009

A. Aschwanden, E. Bueler, and M. Truffer, PISM-A Polythermal Parallel Ice Sheet Model (13MB, PDF), Poster at MOCA-09 Joint Assembly, Montreal, July 2009.

Aschwanden and H. Blatter, Thermodynamics of Polythermal Glaciers and Ice Sheets (700KB, PDF), Poster at AGU Fall Meeting, San Francisco, Dec 2008.

C. Khroulev, E. Bueler, C. Lingle, and J. Brown, Evaluating an Antarctic flow model (PISM) using InSAR surface velocities, (1.5 MB, PDF). Poster at the 15th West Antarctic Ice Sheet (WAIS) Workshop, Oct. 2008, Sterling, Virginia.

E. Bueler, Community tools for model initialization, spin-up, and evaluation, (2 MB, PDF). Presentation at Los Alamos National Laboratory Workshop "Building a Next-Generation Community Ice Sheet Model", August 2008.

E. Bueler, PISM, a Parallel Ice Sheet Model , (8 MB, PDF). Presentation to ARSC Technology Panel, UAF, April 2008.

J. Brown and E. Bueler, Superposition of velocity for ice flow modeling, (3 MB, PDF). Presentation at the European Geosciences Union General Assembly, Vienna, Austria, April 2008.

E. Bueler, Dynamics, Numerics, and Plain Old Ignorance; progress and problems in numerical ice sheet/stream/shelf modeling , (6 MB, PDF). Presentation at NYU CAOS Workshop "Predicting Sea Level in the 21st Century: The Role of Ice-Ocean Interaction", February 2008.

E. Bueler, J. Brown, and C. Lingle. A model of an ice sheet with one ice stream, (2 MB, PDF). Presentation by Bueler at Fall AGU Meeting, San Francisco, December 2007.

M. Truffer. The challenge of predicting the glacial contribution to sea level rise. Poster. November 2007.

C. S. Lingle, R. R. Muskett, and E. Bueler. Ice Dynamics and the Accelerating Glacier and Ice Sheet Contributions to Rising Sea Level, (15 MB, PDF). Presentation at the University of Puerto Rico, September 2007.

E. Bueler, J. Brown, and C. Lingle. The challenge of prediction: developing a polar ice sheet model capable of simulating the responses of ice shelves and ice streams to a warming ocean, (5 MB, PDF). Presentation by Lingle at the University of Puerto Rico, September 2007.

E. Bueler. Using PETSc for scientific computing in parallel, (PDF). Presentation at the Arctic Regional Supercomputer Center (ARSC), UAF, June 2007. Gzipped tar file including three PETSc example codes and the PDF for the talk.

E. Bueler. Ice sheet modelling at UAF and PISM, a Parallel Ice Sheet Model (PDF). Presentation at the Arctic Regional Supercomputer Center (ARSC), UAF, June 2007.

E. L. Bueler, C.S. Lingle, J. A. Brown, and D.N. Covey. Basal motion beneath the Antarctic ice sheet: a comparison of linear and plastic till rheologies in a multi-modal flow model (PDF). Presentation at the European Geosciences Union General Assembly, Vienna, Austria, April 2007.

R. Calov, R. Greve, P. Huybrechts, E. Bueler, C. Ritz, D. Pollard, F. Pattyn, and L. Tarasov. First results of the ISMIP-HEINO model intercomparison project (PDF). Poster at the European Geosciences Union General Assembly, Vienna, Austria, April 2007.

Ed Bueler. On well-posedness and instability for steady temperature-dependent shallow ice flow, (1.5 MB, PDF). Presentation at the SIAM Geosciences meeting, Santa Fe, NM, March 2007.

Craig Lingle, Ed Bueler, Jed Brown, and David Covey. PISM, a Parallel Ice Sheet Model: Current status of our Antarctic ice sheet simulation, (1 MB, PDF). Presentation at the JPL PARCA meeting, 29--31 January 2007.

Ed Bueler, Jed Brown, and Craig Lingle. Verifying thermocoupled ice sheet models (and explaining the "warm spokes"), (3.5 MB, PDF). Presented at the 13th West Antarctic Ice Sheet Workshop, Pack Forest, Washington, September 2006.

Craig Lingle, Jed Brown, and Ed Bueler, Multi-modal flow in a thermocoupled model of the Antarctic ice sheet, with verification, (958 KB, PDF). Presentation at the International Glaciological Society Symposium on Cryospheric Indicators of Global Climate Change, Cambridge, England, August 2006.

Ed Bueler, Craig S. Lingle, and Jed Brown, Fast computation of a viscoelastic deformable Earth model for ice sheet simulations, (444 KB, PDF). Presentation at the International Glaciological Society Symposium on Cryospheric Indicators of Global Climate Change, Cambridge, England, August 2006.

Ed Bueler, Ice Sheets and Obstacle Problems,(1.4 MB, PDF). March 2006 UAF Dept. of Mathematics and Statistics Colloquium.

Ellie Boyce, Roman Motyka, and Ed Bueler, Application of a 1-Dimensional Viscoelastic Bending Beam Model to the Buoyant Terminus of Lake-Calving Mendenhall Glacier, Southeast Alaska, American Geophysical Union, Fall Meeting 2005, abstract #C51A-0265.

Craig Lingle, Ed Bueler, and Jed Kallen-Brown, Toward Multi-Modal Flow in a Thermomechanical Model of the Antarctic Ice Sheet. Presentation at NW Glaciologist's Meeting, U.B.C., Oct. 21-22, 2005 and at the Oct. 24-26, 2005 planning meeting for NASA's Cryospheric Sciences Program.

Ed Bueler, Jed A. Kallen-Brown, and Craig S. Lingle, Exact solutions and the verification of numerical models for ice sheets (250 KB, PNG format). Poster at the European Geosciences Union 2005 General Assembly, Vienna, Austria.

Kallen-Brown, J.A., E.L. Bueler, C.S. Lingle, and D.N. Covey. A 3-D thermomechanical ice-sheet model: preliminary tests with the Goldsby-Kohlstedt flow law. Presented at the 10th West Antarctic Ice Sheet Workshop, 17-20 Sept. 2003, Sterling, Virginia.

Lingle, C.S., E.L. Bueler, J.A. Kallen-Brown, and D.N. Covey. A 3-D thermomechanical ice-sheet model: preliminary simulation of the Antarctic ice sheet with the Goldsby-Kohlstedt vs. Glen flow laws. American Geophysical Union, Fall Meeting 2003, abstract #C11C-0832.

Ed Bueler, Introduction to the mathematicsof ice flow. (263 KB, PDF). September 2003 UAF Dept. Mathematical Sciences Colloquium.

Student work:

Will Mitchell,Exact and numerical solutions for Stokes flow in glaciers,M.S. Mathematics (thesis), UAF 2012. Slides from defense.

Daniella Dellagiustina,Regional modeling of Greenland’s outlet glaciers with the Parallel Ice Sheet Model, M.S. Computational Physics, thesis, 2011.

Ben Sperisen, Ice Sheet Modelling: Numerics and Visualization, final paper and presentation from ARSC Undergraduate Research Challenge, Summer 2008. Here are IDV animations by Ben Sperisen of PISM output (animated GIFs; from EISMINT-Greenland CCL3 runs; for illustration of visualization possibilities):

Nathan Shemonski, Greenland in parallel, final paper from ARSC Undergraduate Research Challenge, Summer 2007.

Jed Brown, Multi-modal ice sheet dynamics: theory and implementation, M.S. Mathematics, UAF, project, 2006.

Latrice Bowman, Numerical analysis of ice flow: numerical solutions using finite difference approximations, M.S. Mathematics, UAF, project, 2002.

Codes for verification:

The current suite of verification tests for PISM includes many different exact solutions. Source codes for all of these, and some documentation, are included in the PISM source code---see src/verif/tests/---and in the PISM User's Manual. See the PISM homepage at www.pism-docs.org.