Spatial patterns of basal drag inferred using control methods from a full‐Stokes and simpler models for Pine Island Glacier, West Antarctica

Basal drag is a fundamental control on ice stream dynamics that remains poorly understood or constrained by observations. Here, we apply control methods on ice surface velocities of Pine Island Glacier, West Antarctica to infer the spatial pattern of basal drag using a full-Stokes (FS) model of ice...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Morlighem, M, Rignot, E, Seroussi, H, Larour, E, Dhia, H Ben, Aubry, D
Format: Article in Journal/Newspaper
Language:unknown
Published: eScholarship, University of California 2010
Subjects:
Meteorology & Atmospheric Sciences
Antarc*
Antarctica
Pine Island
Pine Island Glacier
West Antarctica
Online Access:https://escholarship.org/uc/item/8x35n9nw
https://escholarship.org/content/qt8x35n9nw/qt8x35n9nw.pdf
https://doi.org/10.1029/2010gl043853
Description
Summary:Basal drag is a fundamental control on ice stream dynamics that remains poorly understood or constrained by observations. Here, we apply control methods on ice surface velocities of Pine Island Glacier, West Antarctica to infer the spatial pattern of basal drag using a full-Stokes (FS) model of ice flow and compare the results obtained with two commonly-used simplified solutions: the MacAyeal shelfy stream model and the Blatter-Pattyn model. Over most of the model domain, the three models yield similar patterns of basal drag, yet near the glacier grounding-line, the simplified models yield high basal drag while FS yields almost no basal drag. The simplified models overestimate basal drag because they neglect bridging effects in an ice stream region of rapidly varying ice thickness. This result reinforces theoretical studies that a FS treatment of ice flow is essential near glacier grounding lines. © 2010 by the American Geophysical Union.

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