Results from the Ice-Sheet Model Intercomparison Project-Heinrich Event INtercOmparison (ISMIP HEINO)

R. Calov (1) , R. Greve (2) , A. Abe-Ouchi (3) , E. Bueler (4) , P. Huybrechts (5) , J. V. Johnson (6) , F. Pattyn (7) , D. Pollard (8) , C. Ritz (9) , F. Saito (10) , L. Tarasov (11)

1 PIK - Potsdam Institute for Climate Impact Research
2 Institute of Low Temperature Science [Sapporo]
3 CCSR - Center for Climate System Research [Kashiwa]
4 Dept. of Mathematics and Statistics
5 Departement Geografie
6 Department of Computer Science
7 Laboratoire de Glaciologie
8 Earth and Environmental Systems Institute
9 EDGe
10 JAMSTEC - Japan Agency for Marine-Earth Science and Technology
11 Department of Physics and Physical Oceanography

Results from the Heinrich Event INtercOmparison (HEINO) topic of the Ice-Sheet Model Intercomparison Project (ISMIP) are presented. ISMIP HEINO was designed to explore internal large-scale ice-sheet instabilities in different contemporary ice-sheet models. These instabilities are of interest because they are a possible cause of Heinrich events. A simplified geometry experiment reproduces the main characteristics of the Laurentide ice sheet, including the sedimented region over Hudson Bay and Hudson Strait. The model experiments include a standard run plus seven variations. Nine dynamic/thermodynamic ice-sheet models were investigated; one of these models contains a combination of the shallow-shelf (SSA) and shallow-ice approximation (SIA), while the remaining eight models are of SIA type only. Seven models, including the SIA-SSA model, exhibit oscillatory surges with a period of ∼1000 years for a broad range of parameters, while two models remain in a permanent state of streaming for most parameter settings. In a number of models, the oscillations disappear for high surface temperatures, strong snowfall and small sediment sliding parameters. In turn, low surface temperatures and low snowfall are favourable for the ice-surge cycles. We conclude that further improvement of ice-sheet models is crucial for adequate, robust simulations of cyclic large-scale instabilities.

Domaines: Glaciologie

R. Calov, R. Greve, A. Abe-Ouchi, E. Bueler, P. Huybrechts, et al.. Results from the Ice-Sheet Model Intercomparison Project-Heinrich Event INtercOmparison (ISMIP HEINO). Journal of Glaciology, 2010, 56 (197), pp.371-383. ⟨10.3189/002214310792447789⟩. ⟨insu-00554220⟩