HR: 0800h
AN: PP21B-1381    [Abstracts]
TI: Regional Response of Central Beringian Climate to Circumarctic Ice Sheets and Orbital Parameters Since the Last Interglaciation: Model-Data Comparisons
AU: * Elia, D
EM: delia@geo.umass.edu
AF: Department of Geosciences, University of Massachusetts, 233 Morrill Science Center, Amherst, MA 01003 United States
AU: DeConto, R
EM: deconto@geo.umass.edu
AF: Department of Geosciences, University of Massachusetts, 233 Morrill Science Center, Amherst, MA 01003 United States
AU: Brigham-Grette, J
EM: juliebg@geo.umass.edu
AF: Department of Geosciences, University of Massachusetts, 233 Morrill Science Center, Amherst, MA 01003 United States
AB: The quaternary history of Beringia is marked by rapid glacial advances during periods of high eustatic sea level versus relatively limited ice extent when circumarctic ice sheets are growing at or near maximum. It is widely understood that changes in insolation are a primary forcing behind the growth and decay of continental ice sheets, but Beringian glaciations appear to be responding, on a regional scale, differently than the major ice sheets of the Northern hemisphere. Building on the work of field researchers in Siberia and Alaska, model-data comparisons are conducted to examine the mechanisms driving Beringian glaciations since the last interglacial. Boundary conditions are based on field data to set initial conditions of Northern hemisphere ice-extent, atmospheric and sea surface temperatures, sea level, and insolation. Simulations are run at 120,000 ka, 70,000ka, and 30,000ka with boundary conditions manipulated to examine the influence of large ice sheets on atmospheric circulation and moisture availability to the Beringian region. Other factors investigated include the effect of changes in sea surface temperature on Beringian climate, as well as alternate flooding and exposure of the Bering land bridge. The model simulations attempt to reproduce conditions evidenced by the data and test hypotheses for the underlying mechanisms driving Beringian glaciations. Ultimately, it is hoped that this research may shed light on the interplay between insolation, temperature, and moisture availability contributing to the growth of circumarctic ice sheets.
DE: 9315 Arctic region
DE: 3337 Numerical modeling and data assimilation
DE: 3344 Paleoclimatology
DE: 4207 Arctic and Antarctic oceanography
DE: 4556 Sea level variations
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting