Published In

Journal of Geophysical Research

Document Type

Article

Publication Date

11-1-1999

Subjects

Ice sheets -- Antarctica -- Mathematical models, Glaciers -- Antarctica -- West Antarctica, Ice mechanics -- Mathematical models, Ice -- Dynamics

Abstract

We have developed a dynamic/thermodynamic finite element numerical model that couples inland ice sheet, ice stream, and ice shelf dynamics. This new model stands apart from other whole ice sheet models in its explicit treatment of ice stream flow. Additionally, the model accounts for both horizontal and vertical advection and diffusion of temperature in the flowing ice. In present day simulations of the West Antarctic Ice Sheet (WAIS), modeled ice velocity agrees well with observed ice flow. In particular, the model reproduces the pattern of speed variation across ice streams although the continuous downstream speed up of ice flow cannot be reproduced without concurrent downstream variation in basal friction. Model thermodynamics, evaluated qualitatively by model prediction of the spatial distribution of basal melting and quantitatively by comparison with ice temperature measured in boreholes at several locations, are sound. In particular, the model reproduces the broad pattern of frozen-bed inter-ice stream ridges and melted-bed ice streams. Model initialization for long-time simulations is somewhat limited by computation time and by a thermodynamic feedback at sites of large viscous heating that can be a problem in heat balance only model initializations. Methods for averting those initialization problems are discussed. The new model can accommodate a variety of boundary conditions (such as various bed rheologies) and is well-suited to investigate the origin and evolution of WAIS ice streams within the context of the whole ice sheet system.

Description

This is the publisher's final pdf. Originally published in Journal of Geophysical Research (http://www.agu.org/journals/jb/) and is copyrighted by American Geophysical Union (http://www.agu.org/)

DOI

10.1029/1999JB900264

Persistent Identifier

http://archives.pdx.edu/ds/psu/8449

Included in

Geology Commons

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