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The importance of geothermal heat flux in modelling of the Antarctic Ice Sheet

conference contribution
posted on 2023-05-24, 18:32 authored by Phipps, S, Jacqueline HalpinJacqueline Halpin
Ice sheet models are the only physically-based tools that allow us to simulate the future evolution of the Antarctic Ice Sheet, including its contribution towards changes in global sea level. However, due to limitations in our understanding of ice sheet dynamics, modelling is an inherently uncertain exercise. A typical approach towards optimising ice sheet models is to "tune" key physical parameters by finding the values that give the most realistic simulations of the present-day ice sheet, based on criteria such as ice sheet geometry or ice velocity. However, this approach assumes that there are no errors in the boundary conditions being used to drive the models.

Here, we use the Parallel Ice Sheet Model to explore the sensitivity of the simulated Antarctic Ice Sheet to the available geothermal heat flux (GHF) datasets. We find that the choice of GHF is a significant source of uncertainty, leading to basin-wide differences in excess of 1000m in the simulated ice thickness. Using different GHF datasets to drive the model, we then "tune" it by determining the optimal values of key physical parameters. We show that the parameter combinations obtained are sensitive to the choice of GHF.

Our results highlight the importance of GHF in ice sheet modelling. Reliable GHF estimates are critical to optimising numerical models of the Antarctic Ice Sheet and, therefore, to reducing uncertainty in projections of future global sea level rise.

History

Publication title

Geophysical Research Abstracts

Volume

20

Pagination

11314

ISSN

1607-7962

Department/School

Institute for Marine and Antarctic Studies

Publisher

Copernicus GmbH

Place of publication

Germany

Event title

20th EGU General Assembly, EGU2018

Event Venue

Vienna, Austria

Date of Event (Start Date)

2018-04-04

Date of Event (End Date)

2018-04-13

Repository Status

  • Restricted

Socio-economic Objectives

Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)

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