Presented as part of an international press conference in Stockholm on September 27 and officially released this Monday, September 30, 2013, the fifth IPCC assessment report marks a new stage in the world's scientific contribution to the understanding and awareness of impact of man on our climate. Results obtained from numerical experiments conducted with the ice sheet/ice flow model Elmer/Ice are largely included in this new report. The 9 cited references including results from Elmer/Ice are:
Bindschadler, R. A. et al., 2013. Ice-sheet model sensitivities to environmental forcing and their use in projecting future sea level (the SeaRISE project), Journal of Glaciology, Vol. 59(214), p. 195-224, doi:10.3189/2013JoG12J125. [link to paper]
Durand G. et al., 2009. Full Stokes modeling of marine ice sheets: influence of the grid size, Ann. Glaciol., 50(52), 109–114.
Favier L. et al., 2012. A three-dimensional full Stokes model of the grounding line dynamics: effect of a pinning point beneath the ice shelf, The Cryosphere, 6, 101-112, doi:10.5194/tc-6-101-2012. [link to paper]
Gillet-Chaulet, F. et al., 2012. Greenland ice sheet contribution to sea-level rise from a new-generation ice-sheet model, The Cryosphere, 6, 1561-1576, doi:10.5194/tc-6-1561-2012. [link to paper]
Gudmundsson, G. H. et al., 2012. The stability of grounding lines on retrograde slopes, The Cryosphere, 6, 1497-1505, doi:10.5194/tc-6-1497-2012. [link to paper]
Nowicki, S. et al., 2013. Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland. Journal of Geophysical Research: Earth Surface 118 (2), 1025-1044, doi:10.1002/jgrf.20076. [link to paper]
Pattyn, F. et al., 2013. Grounding-line migration in plan-view marine ice-sheet models: results of the ice2sea MISMIP3d intercomparison, J. Glaciol., 59, doi:10.3189/2013JoG12J129.
Seddik H., R. Greve, T. Zwinger, F. Gillet-Chaulet and O. Gagliardini, 2012. Simulations of the Greenland ice sheet 100 years into the future with the full Stokes model Elmer/Ice, J. Glaciol., 58(209), 427-440. [link to paper]
Shannon, S. R., et al., 2013. Enhanced basal lubrication and the contribution of the Greenland ice sheet to future sea-level rise, PNAS, 110(35), 14156--14161, doi:10.1073/pnas.1212647110.
Evolution of glaciers in response to climate change has mostly been simulated using simplified dynamical models. Because these models do not account for the influence of high-order physics, corresponding results may exhibit some biases. For Haig Glacier in the Canadian Rocky Mountains, we test this hypothesis by comparing simulation results obtained from 3-D numerical models that deal with different assumptions concerning physics, ranging from simple shear deformation to comprehensive Stokes flow. In glacier retreat scenarios, we find a minimal role of high-order mechanics in glacier evolution, as geometric effects at our site (the presence of an overdeepened bed) result in limited horizontal movement of ice (flow speed on the order of a few meters per year). Consequently, high-order and reduced models all predict that Haig Glacier ceases to exist by ca. 2080 under ongoing climate warming. The influence of high-order mechanics is evident, however, in glacier advance scenarios, where ice speeds are greater and ice dynamical effects become more important. Although similar studies on other glaciers are essential to generalize such findings, we advise that high-order mechanics are important and therefore should be considered while modeling the evolution of active glaciers. Reduced model predictions may be adequate for other glaciologic and topographic settings, particularly where flow speeds are low and where mass balance changes dominate over ice dynamics in determining glacier geometry.
Reference: Adhikari, S. and S. J. Marshall, 2013. Influence of high-order mechanics on simulation of glacier response to climate change: insights from Haig Glacier, Canadian Rocky Mountains, The Cryosphere, 7, 1527-1541, doi:10.5194/tc-7-1527-2013. [pdf]
The Sea-level Response to Ice Sheet Evolution (SeaRISE) effort explores the sensitivity of the current generation of ice sheet models to external forcing to gain insight into the potential future contribution to sea level from the Greenland and Antarctic ice sheets. All participating models (including Elmer/Ice) simulated the ice sheet response to different types of external forcings. In Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland, an analysis of the spatial response of the Greenland ice sheet is presented, and the impact of model physics and spin-up on the projections is explored. As one of the results, Figure 6 from the paper shows the ensemble mean thickness change from the (a) control and (b) standard deviation resulting from the S2 experiment (doubled basal sliding) after 100 simulated years, along with the thickness contribution from the (c) maximum (Elmer/Ice) and (d) minimum (PISM) models.
Reference: Nowicki et al., 2013. Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland. Journal of Geophysical Research: Earth Surface 118 (2), 1025-1044, doi:10.1002/jgrf.20076. [link to paper]