Short-term fluctuations of West Antarctic ice streams - model resultsEntry ID: nsfopp0096302
Abstract: This project was aimed primarily at understanding the role of subglacial till
beds in controlling transient behavior of ice streams and ice sheets. Research
tools included a numerical model of ice stream flow over a till bed whose
properties were allowed to evolve through time in response to changes in basal
freezing and melting. This is the very first numerical model of ... coupled
ice-till flow with a transient evolution of till properties (e.g. strength).
The new numerical model was used to investigate the transient behavior of the
soft-bedded West Antarctic ice streams. Two of our publications resulting from
this work describe applications of the coupled ice-till model in simulations
of: (1) the stoppage of Ice Stream C (~150 years ago) [Bougamont et al., 2003]
and (2) the slowdown of Whillans Ice Stream, which occurred at least between
1974 and 1997 and may be continuing further [Joughin et al., 2002].
Short-term fluctuations of West Antarctic ice streams - model results
data_set_summary: This data set consists of 12 data files and one movie based
on model results. Six of the files (filenames starting with 'ISC') contain
results from numerical simulations of the stoppage of Ice Stream C, West
Antarctica. These simulations are described in detail in Bougamont and others
[2003 - JGR]. The enclosed movie shows the evolution of the simulated velocity
field of Ice Stream C and its two tributaries over 10000 years. This is a run
in which the ice stream widens at the rate of 1.5 m/yr at the grounding line.
The prescribed widening rate decreases to 0 m/yr at the junction of
Four files (filenames starting with 'WIS') give results of numerical
experiments focused on predicting whether the observed slowdown of Whillans Ice
Stream may result in a near-future shutdown of this ice stream. This work is
described in detail in Bougamont and others [2003 - Annals of Glaciology, v.
Two files (filenames starting with 'ISC_E') give data derived from a modeling
study focused on distribution of erosion and deposition beneath Ice Stream C
simulated over ~10,000 years. Details of this modeling effort are described in
Bougamont and Tulaczyk [2003 - Boreas]
data_format: All twelve data files are tab-delimited ASCII files prepared using
MATLAB software package. One movie file is in AVI format.
data_structure: Each file contains a short header describing the key parameter
settings used in the numerical experiments, from which the data contained in
the files are derived. Data has the form of matrices. Distance along the
centerline of the ice stream is given in columns (horizontal node spacing was 5
km in all runs). Time-evolution of parameters is given in rows (temporal
spacing varies from file to file and is given in the header).
Role: DIF AUTHOR
Email: bauer at nsidc.org
University of Colorado Cooperative Institute for Research in Environmental Sciences CIRES 449 UCB
Province or State: CO
Postal Code: 80309
Email: tulaczyk at es.ucsc.edu
University of California, Santa Cruz Santa Cruz CA
City: Department of Earth Sciences
Province or State: UCSC
Postal Code: 95064
Email: drm7 at midway.uchicago.edu
Department of Geophysical Sciences University of Chicago 5734 S. Ellis Ave
Province or State: IL
Postal Code: 60637
1) Ice Stream C study = Bougamont, M., S. Tulaczyk, and I. Joughin, 2003 in
press, Response of subglacial sediments to basal freeze-on: II. Application to
the stoppage of Ice Stream C, West Antarctica: Journal of Geophysical
Research, v. 108(B4), 2223, doi:10.1029/2002JB001936.
2) Whillans Ice Stream study = Bougamont, M., S. Tulaczyk, and Joughin, I.,
2003 in ... press, Numerical investigations of the slowdown of Whillans Ice Stream,
West Antarctica: is it shutting down like Ice Stream C? Annals of Glaciology.
3) Sub-ice stream erosion study = Bougamont, M., and S. Tulaczyk, in press,
Glacial erosion beneath ice streams and ice-stream tributaries: constraints on
temporal and spatial distribution of erosion from numerical simulations of a
West Antarctic Ice Stream, Boreas., v. 32, p. 178-190.
Creation and Review Dates
DIF Creation Date: 2003-05-06
Last DIF Revision Date: 2010-07-07