Elmer/Ice contributed to the ISMIP6 initMIP-Greenland intercomparison exercice.
Earlier large-scale Greenland ice sheet sea-level projections (e.g. those run during the ice2sea and SeaRISE initiatives) have shown that ice sheet initial conditions have a large effect on the projections and give rise to important uncertainties. The goal of this initMIP-Greenland intercomparison exercise is to compare, evaluate, and improve the initialisation techniques used in the ice sheet modelling community and to estimate the associated uncertainties in modelled mass changes. initMIP-Greenland is the first in a series of ice sheet model intercomparison activities within ISMIP6 (the Ice Sheet Model Intercomparison Project for CMIP6), which is the primary activity within the Coupled Model Intercomparison Project Phase 6 (CMIP6) focusing on the ice sheets. Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of (1) the initial present-day state of the ice sheet and (2) the response in two idealised forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without additional forcing) and in response to a large perturbation (prescribed surface mass balance anomaly); they should not be interpreted as sea-level projections. We present and discuss results that highlight the diversity of data sets, boundary conditions, and initialisation techniques used in the community to generate initial states of the Greenland ice sheet. We find good agreement across the ensemble for the dynamic response to surface mass balance changes in areas where the simulated ice sheets overlap but differences arising from the initial size of the ice sheet. The model drift in the control experiment is reduced for models that participated in earlier intercomparison exercises.
More information: Goelzer, H., S. Nowicki, T. Edwards, M. Beckley, A. Abe-Ouchi, A. Aschwanden, R. Calov, O. Gagliardini, F. Gillet-Chaulet, N. R. Golledge, J. Gregory, R. Greve, A. Humbert, P. Huybrechts, J. H. Kennedy, E. Larour, W. H. Lipscomb, S. Le clec'h, V. Lee, M. Morlighem, F. Pattyn, A. J. Payne, C. Rodehacke, M. Rückamp, F. Saito, N. Schlegel, H. Seroussi, A. Shepherd, S. Sun, R. van de Wal and F. A. Ziemen, 2018. Design and results of the ice sheet model initialisation experiments initMIP-Greenland: an ISMIP6 intercomparison, The Cryosphere, 12, 1433-1460. doi:10.5194/tc-12-1433-2018
Don't miss the 7 Elmer/Ice related posters and orals that will be presented during EGU 2018:
Monday, 9 Apr 2018
Johannes Fürst, Francisco Navarro, Fabien Gillet-Chaulet, Geir Moholdt, Xavier Fettweis, Charlotte Lang, Thorsten Seehaus, Matthias Braun, Douglas Benn, Toby Benham, Julian Dowdeswell, Mariusz Grabiec, Jack Kohler, Katrin Lindbäck, Rickard Pettersson, and Heïdi Sevestre. The ice-free topography of Svalbard, Mon, 09 Apr, 14:00–14:15, Room N1
Tuesday, 10 Apr 2018
Joe Todd, Jan Åström, Doug Benn, Thomas Zwinger, and Poul Christoffersen. 3D Calving Modelling of Store Glacier and Rink Isbrae using Elmer/Ice and HiDEM, Tue, 10 Apr, 17:30–19:00, Hall X4, X4.20
Wednesday, 11 Apr 2018
Lionel Favier, Nicolas Jourdain, Nacho Merino, Gael Durand, Olivier Gagliardini, and Fabien Gillet-Chaulet. Ice/Ocean coupled model based recommendations for sub-shelf melting parameterisations in standalone ice-sheet modelling, Wed, 11 Apr, 17:30–19:00, Hall X5, X5.377
Carlo Licciulli, Pascal Bohleber, Josef Lier, Olivier Gagliardini, Martin Hoelzle, Olaf Eisen, and Dietmar Wagenbach. Full Stokes ice-flow modeling of the high -Alpine glacier saddle Colle Gnifetti, Monte Rosa,Wed, 11 Apr, 17:30–19:00, Hall X5, X5.377
Clemens Schannwell, Reinhard Drews, Christoph Mayer, Olaf Eisen, Emma C. Smith, Todd A. Ehlers, Fabien Gillet-Chaulet, and Olivier Gagliardini. Fully-coupled 3D modelling of Hal, vfarryggen Ice Rise, Dronning Maud Land, East AntarcticaWed, 11 Apr, 09:00–09:15, Room L3
Thursday, 12 Apr 2018
Sainan Sun, Reinhard Drews, Frank Pattyn, Keith Nicholls, and Sophie Berger. Basal melt rate variability across ice-shelf channels in Dronning Maud Land, Antarctica, Thu, 12 Apr, 10:44–10:46, PICO spot 4
Friday, 13 Apr 2018
Sophie Berger, Reinhard Drews, Veit Helm, Niklas Neckel, Sainan Sun, Frank Pattyn, and Olaf Eisen. Detecting high spatial variability of ice-shelf basal mass balance, Fri, 13 Apr, 11:30–11:45, Room N1
With Elmer/Ice among a multitude of models, including surface energy balance and runoff, a simple basal hydrological model as well as a plume and a discrete element model, the authors investigate the influence of undercutting caused by plumes fed by runoff entering the glacier and released at certain outlets by basal hydrological flowpaths as well as sliding on calving rates at Kronebreen, Svalbard. The authors are able to show the influence of undercutting as well as basal sliding on calving rates of this fast flowing tidewater. Sliding coefficients have been obtained from a temporal and spatial high resolution satellite data-set. Those obtained friction coefficients - as well as the geometry obtained from the undercut model and Elmer/Ice are used in the discrete element model HIDEM to simulate the calving behaviour, which then are compared to measured front positions.
Read more: Vallot, D., J. Åström, T. Zwinger, R. Pettersson, A. Everett, D.I. Benn, A. Luckman, W.J.J. van Pelt, F. Nick, and J. Kohler, 2018. Effects of undercutting and sliding on calving: a global approach applied to Kronebreen, Svalbard. The Cryosphere, 12, 609-625, doi:10.5194/tc-12-609-2018