HR: 1340h
AN: PP13B-1275    [Abstracts]
TI: Shallow Ocean Overturning and the Heat Flux and Carbon Content of the Glacial Warm Pool Since the Last Glacial Maximum
AU: * Anderson, D M
EM: david.m.anderson@noaa.gov
AF: Paleoclimatology Branch, NOAA's National Climatic Data Center, 325 Broadway, Boulder, CO 80305, United States
AU: * Anderson, D M
EM: david.m.anderson@noaa.gov
AF: INSTAAR, University of Colorado, Boulder, CO 80303, United States
AU: Zhang, H
EM: Huai-min.Zhang@noaa.gov
AF: Scientific Services Division, NOAA's National Climatic Data Center, 151 Patton Ave, Boulder, CO 28801, United States
AB: The correspondence between temperature and carbon dioxide during the Quaternary glacial cycles is one of the most remarkable aspects of the paleoclimate record, directly relevant to prediction of future climate change due to carbon dioxide. Increased ocean stratification at high latitudes appears to play a part, reducing mixing between the carbon-poor surface ocean and the carbon-rich abyss during glacial times. Little evidence exists regarding the possible contribution of the shallow overturning circulation that ventilates the upper thermocline. Our investigation reveals that vertical ocean gradients in temperature and carbon in the upper kilometer were steeper at the Last Glacial Maximum, and turbulent diffusion at the base of the warm pool was reduced by 20 percent or more. The steeper vertical gradients, unexpectedly-small surface cooling, and lower carbon content of the glacial warm pool may be explained by reduced shallow overturning. The shallow overturning hypothesis links the carbon and heat content of the tropical ocean with the shallow overturning and hence the winds and the low-high latitude thermal gradient. This is significant for the future because warmer climates mix carbon out of the deep sea at a faster rate.
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4926 Glacial
DE: 4936 Interglacial
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting