HR: 0830h
AN: C31C-0408    [PDF]
TI: Ice Shelf Front Readjustment in Response to Inflow Perturbations: Towards a new Model of Ice Shelf Disintegration
AU: * Christoffersen, P
EM: poul@es.ucsc.edu
AF: Earth Sciences Department, University of California, Santa Cruz, 1158 High St., Santa Cruz, CA 95064 United States
AU: Tulaczyk, S
EM: tulaczyk@es.ucsc.edu
AF: Earth Sciences Department, University of California, Santa Cruz, 1158 High St., Santa Cruz, CA 95064 United States
AU: Joughin, I
EM: ian@radar-sci.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: The Ross Ice Shelf has in its recent past seen a significant reduction of ice influx. The stoppage of Ice Stream C, about 150 years ago, reduced inflow of ice by 20-30 km$^{3}$/yr. Adding to this trend is the current slowdown of Whillans Ice Stream, which has averaged 5 m/yr$^{2}$ over the last 23 years. The loss of annual ice influx may become as high as 50-60 km$^{3}$/yr should Whillans Ice Stream come to a complete stop as predicted by numerical models. This influx reduction constitute a major perturbation that could trigger a critical rearrangement of the ice shelf. The collapse of smaller West Antarctic ice shelves has shown that floating ice fronts can retreat rapidly. We have developed a new numerical ice shelf model that includes a mobile ice shelf front, which can adjusts to changes in ice thickness and velocity field. The dynamic ice front condition allows us to investigate the dynamics of collapsing ice shelves. Initial model results based on simplified ice shelf geometry showed that both location and curvature of the floating ice front change in response to inflow perturbations. We intend to use our model to predict future changes in the Ross Ice Shelf due to decreasing discharge from the Ross Ice Streams. Retreat of the Ross Ice Shelf front could expose up to 400,000 km$^{2}$ of new polar sea surface area. Such exposure may change the regional sea ice conditions and maybe even cause rearrangement of the thermohaline ocean circulation.
UR: http://es.ucsc.edu/~poul
DE: 1827 Glaciology (1863)
DE: 1863 Snow and ice (1827)
DE: 3210 Modeling
DE: 3309 Climatology (1620)
SC: Cryosphere [C]
MN: 2003 Fall Meeting