HR: 0800h
AN: PP41C-0683    [Abstracts]
TI: Fresh water forcing hypothesis of abrupt climate change: A test of consistency with sea level reconstructions
AU: * Lu, S
EM: splu@mail.utexas.edu
AF: Department of Physics, The University of Texas at Austin, Institute for Geophysics The John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin J.J. Pickle Research Campus, Bldg. 196 (ROC) 10100 Burnet Rd. (R2200), Austin, TX 78758, United States
AU: Jackson, C
EM: charles@utig.ig.utexas.edu
AF: Institute for Geophysics, The University of Texas at Austin, Institute for Geophysics The John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin J.J. Pickle Research Campus, Bldg. 196 (ROC) 10100 Burnet Rd. (R2200), Austin, TX 78758, United States
AU: Marchal, O
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole Oceanographic Institution Clark 109A, MS#23, Woods Hole, MA 02543, United States
AU: Liu, Y
AF: Department of Physics, The University of Texas at Austin, Institute for Geophysics The John A. and Katherine G. Jackson School of Geosciences The University of Texas at Austin J.J. Pickle Research Campus, Bldg. 196 (ROC) 10100 Burnet Rd. (R2200), Austin, TX 78758, United States
AU: Thompson, W
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole Oceanographic Institution Clark 109A, MS#23, Woods Hole, MA 02543, United States
AU: Stocker, T
AF: Physics Institute, University of Bern, Climate and Environmental Physics University of Bern Sidlerstrasse 5, Bern, 3012, Switzerland
AB: A synthesis is made of observational and modeling perspectives of abrupt climate change in order to test their consistency with the fresh water forcing hypothesis. The synthesis is carried out using stochastic inverse modeling of a 4-box model of the ocean's meridional overturning circulation (MOC) in order to infer the volume of fresh water input to the North Atlantic that is required to explain the Greenland ice core proxy records of abrupt climate change from 39 ka to 30 ka. The similarity in the amplitude and timing of predicted sea level change with reconstructions from the geologic record give added support to the fresh water forcing hypothesis. In particular, the inversion suggests that the duration of the abrupt warmings should be directly related to the volume of land ice growth. This conclusion is unaffected by uncertainties in the processes that govern mixing of deep polar waters into the tropical thermocline. The fresh water forcing solutions were also able to reproduce the Greenland data within the seasonally-resolving Bern climate model (Schmittner and Stocker, 1999, J Clim), suggesting that the solutions may be valid forcing scenarios for more realistic ocean GCMs.
DE: 1641 Sea level change (1222, 1225, 4556)
DE: 3260 Inverse theory
DE: 4568 Turbulence, diffusion, and mixing processes (4490)
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4962 Thermohaline
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting