A New Collaborative Ice Sheet Modelling Program

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

Abstract OPP-0082453 Cuffey This is a collaborative proposal with Principal Investigators from the Universities of California-Berkeley and Calgary. The Greenland ice sheet is a rich repository for paleoclimate information and may contribute to substantial increases in global sea level. The Principal Investigators will develop a model to improve understanding of Greenland ice sheet dynamics and history; this will complement existing modeling programs at European universities and institutes. The work will improve understanding of: 1) controls on accumulation rate (through more accurate historical reconstructions), 2) flow dynamics through the role of ice stream flow, and 3) response to climate forcings (by investigating response to spatially variable forcings of temperature and precipitation rate). They will develop a numerical fully three-dimensional thermomechanical model of the ice sheet using a realistic geographic domain by Dr. P. Huybrechts. The specific objectives include: 1) To improve the accumulation rate history derived from the Greenland Ice Sheet Project 2 (GISP 2) ice core and establish uncertainties for this record. No attempt has been made to reconstruct accumulation rate history from the Greenland ice cores that is consistent with the partial dynamics of the whole ice sheet 2) To improve the general methodology for derivation of accumulation rate from ice cores. This will be the first attempt to link accumulation rate reconstructions to the dynamic predictions of a whole ice sheet model. 3) To improve understanding of Greenland ice sheet dynamics by accounting for fast flow in ice streams. The enormous ice flux through the Jakobshavn ice stream has not been resolved in whole ice sheet models, but this system affects a large region of the ice sheet and probably allows the ice sheet to respond more rapidly to climate change than is usually calculated. 4) To improve understanding of the response of the Greenland ice sheet to climate change by the response to spatially varying forcings. Century-scale climatic forcing for the model ice sheet will be derived from the NCAR Climate System Model, a coupled ocean-atmosphere-sea ice-land surface model.