Monday, February 17, 2014

New paper finds Greenland melted much more during the prior interglacial than present-day

A paper under open review for The Cryosphere finds that during the last interglacial [Eemian], melting of the Greenland ice sheet produced 1.4 meters more sea level rise than during the current interglacial. The paper adds to many other peer-reviewed publications demonstrating that the last interglacial was much warmer than the present, Greenland 8C warmer, sea levels up to 31 feet higher, and there is no evidence that the current interglacial is any different. 

The Cryosphere Discuss., 8, 1151-1189, 2014
Simulating the Greenland ice sheet under present-day and palaeo constraints including a new discharge parameterization
R. Calov1, A. Robinson1,2,3, M. Perrette1, and A. Ganopolski1
1Potsdam Institute for Climate Impact Research, Potsdam, Germany
2Universidad Complutense Madrid, 28040 Madrid, Spain
3Instituto de Geociencias, UCM-CSIC, 28040 Madrid, Spain

Abstract. In this paper, we propose a new sub-grid scale parameterization for the ice discharge into the ocean through outlet glaciers and inspect the role of different observational and palaeo constraints for the choice of an optimal set of model parameters. This parameterization was introduced into the polythermal ice-sheet model SICOPOLIS, which is coupled to the regional climate model of intermediate complexity REMBO. Using the coupled model, we performed large ensemble simulations over the last two glacial cycles. We exploit two major parameters: a melt parameter in the surface melt scheme of REMBO and an ice discharge parameter in our parameterization of ice discharge. Our constraints are the present-day Greenland ice sheet surface elevation, surface mass balance partition (ratio between ice discharge and total precipitation) and the Eemian interglacial elevation drop relative to present-day in the vicinity of the NEEM ice core. We show that the ice discharge parameterization enables us to simulate both the correct ice-sheet shape and mass balance partition at the same time without explicitly resolving the Greenland outlet glaciers. For model verification, we compare simulated total and sectoral ice discharge with those from other findings, including observations. For the model versions, which are inside the range of observational and palaeo constraints, our simulated Greenland ice sheet contribution to Eemian sea level rise relative to present-day amounts to 1.4 m on average (in the range of 0.6 and 2.5 m)

1 comment:

  1. During the Hypsithermal, 5,000 years ago, when the Sahara still supported large animals, fish and humans. sea level was 2 meters (6 feet) higher than now.

    I have confirmed this by field work and so have many others.