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Geothermal heat flux (GHF) is one of the key thermal boundary conditions for ice-sheet models. We assess the sensitivity of the Lambert-Amery glacial system in East Antarctica to four different GHF datasets using a regional ice-sheet model. A control solution of the regional model is initialised by minimising the misfit to observations through an optimisation process. The Lambert-Amery glacial system simulation contains temperate ice up to 150 m thick and has an average basal melt of 1.3 mm a⁻¹, with maximum basal melting of 504 mm a⁻¹. The simulations which use a relatively high GHF compared to the control solution increase the volume and area of temperate ice, which causes higher surface velocities at higher elevations, which leads to the advance of the grounding line. The grounding line advance leads to changes in the local flow configuration, which dominates the changes within the glacial system. To investigate the difference in spatial patterns within the geothermal datasets, they were scaled to have the same median value. These scaled GHF simulations showed that the ice flow was most sensitive to the spatial variation in the underlying GHF near the ice divides and on the edges of the ice streams.

Item Type:	Refereed Article
Keywords:	geothermal heat flux, ice sheet model, ice flow
Research Division:	Earth Sciences
Research Group:	Physical Geography and Environmental Geoscience
Research Field:	Glaciology
Objective Division:	Environment
Objective Group:	Climate and Climate Change
Objective Field:	Effects of Climate Change and Variability on Antarctic and Sub-Antarctic Environments (excl. Social Impacts)
Author:	Pittard, ML (Mr Mark Pittard)
Author:	Roberts, JL (Dr Jason Roberts)
Author:	Galton-Fenzi, BK (Dr Ben Galton-Fenzi)
Author:	Watson, CS (Dr Christopher Watson)
ID Code:	114791
Year Published:	2016
Web of Science® Times Cited:	2
Deposited By:	CRC-Antarctic Climate & Ecosystems
Deposited On:	2017-02-27
Last Modified:	2017-10-30
Downloads:	13 View Download Statistics