HR: 08:30h
AN: PP11C-03    [Abstracts]
TI: Subtropical Atlantic salinity variability and Atlantic meridional circulation during the last deglaciation
AU: * Carlson, A E
EM: acarlson@geology.wisc.edu
AF: Department of Geology and Geophysics, University of Wisconsin, Madison, WI 53706, United States
AU: Oppo, D W
EM: doppo@whoi.edu
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
AU: Came, R E
EM: rcame@gps.caltech.edu
AF: Geology & Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States
AU: LeGrande, A N
EM: legrande@giss.nasa.gov
AF: National Aeronautics and Space Administration Goddard Institute for Space Studies and Center for Climate Systems Research, Columbia University, New York, NY 10025, United States
AU: Keigwin, L D
EM: lkeigwin@whoi.edu
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
AU: Curry, W B
EM: wcurry@whoi.edu
AF: Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States
AB: During the last deglaciation (21 to 10 kyr BP), freshening of the surface of the North Atlantic likely caused reductions in Atlantic meridional overturning circulation (AMOC); what forced subsequent resumptions remains poorly understood. Here we present three new deglacial sea surface salinity (SSS) reconstructions from the subtropical North and South Atlantic combined with general circulation model (GCM) simulations that show synchronous changes in SSS between the hemispheres. Parallel changes in our subtropical SSS records and tropical Caribbean and western Atlantic SSS indicate that a salty surface water mass accumulated in the western Atlantic from 27 degrees South to 33 degrees North during periods of reduced AMOC in agreement with GCM results. However, SSS decreases led AMOC resumption by approximately 500 years, which can be explained by the establishment of shallow overturning circulation that could have triggered through various feedbacks full AMOC resumption. This implies that AMOC may contain an internal, self-limiting feedback.
DE: 1065 Major and trace element geochemistry
DE: 4924 Geochemical tracers
DE: 4928 Global climate models (1626, 3337)
DE: 4938 Interhemispheric phasing
DE: 4962 Thermohaline
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting