Pre-LGM Northern Hemisphere ice sheet topography

• DOI: 10.5194/cp-9-2365-2013
• Publication Date: 2013-10-22T12:32:22Z
• Authors: J. Kleman; J. Fastook; K. Ebert; J. Nilsson; R. Caballero
• Keywords: Ice-sheet model; Greenland ice sheet; Marine isotope stage

Abstract. We here reconstruct the paleotopography of Northern Hemisphere ice sheets during glacial maxima marine isotope stages (MIS) 5b and 4.We employ a combined approach, blending geologically based reconstruction numerical modeling, to arrive at probable sheet extents topographies for each these two time slices. For physically 3-D calculation on derived 2-D constraints, we use University Maine Ice Sheet Model (UMISM) calculate thickness topography. The approach modeling strategy is designed provide robust data sets sufficient resolution atmospheric circulation experiments previously elusive periods. Two tunable parameters, temperature scaling function applied spliced Vostok–GRIP record, spatial adjustment climatic pole position, were employed iteratively achieve good fit geological constraints where such available. model credibly reproduces first-order pattern size location indicated (86.2 kyr age) 4 (64 age). From interglacial state north–south obstacles (Rocky Mountains Greenland), by MIS emergence Quebec–central Arctic Scandinavian–Barents-Kara had increased number highland four. major remained constant through 4, but merging Cordilleran proto-Laurentide produced single continent-wide North American LGM.