Sensitivity of centennial mass loss projections of the Amundsen basin to the friction law
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Published:2019-01-22
Issue:1
Volume:13
Page:177-195
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ISSN:1994-0424
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Container-title:The Cryosphere
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language:en
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Short-container-title:The Cryosphere
Author:
Brondex Julien, Gillet-Chaulet FabienORCID, Gagliardini OlivierORCID
Abstract
Abstract. Reliable projections of ice sheets' future contributions to sea-level rise require models that are able to accurately simulate grounding-line
dynamics, starting from initial states consistent with observations. Here, we
simulate the centennial evolution of the Amundsen Sea Embayment in response
to a prescribed perturbation in order to assess the sensitivity of mass loss
projections to the chosen friction law, depending on the initialisation
strategy. To this end, three different model states are constructed by
inferring both the initial basal shear stress and viscosity fields with
various relative weights. Then, starting from each of these model states,
prognostic simulations are carried out using a Weertman, a Schoof and a Budd
friction law, with different parameter values. Although the sensitivity of
projections to the chosen friction law tends to decrease when more weight is
put on viscosity during initialisation, it remains significant for the most
physically acceptable of the constructed model states. Independently of the
considered model state, the Weertman law systematically predicts the lowest
mass losses. In addition, because of its particular dependence on effective
pressure, the Budd friction law induces significantly different grounding-line retreat patterns than the other laws and predicts significantly higher
mass losses.
Publisher
Copernicus GmbH
Subject
Earth-Surface Processes,Water Science and Technology
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