|Deep Ocean Circulation: Last Glacial to Present|
William Curry (WHOI), Rosemarie Came (CalTech), Jerry McManus (WHOI)
The Atlantic Ocean is characterized by a whole ocean overturning cell. Warm, salty tropical upper ocean waters flow northward in the western Atlantic. The heat loss to the overlying cold atmosphere results in a loss of bouyancy, and convection to great depths in the Labrador and Nordic Seas. These newly formed North Atlantic Deep Waters flow southward, eventually exiting the Atlantic basin. Waters that are exported must be replaced. The more vigorous the North Atlantic overturning and southward export, the more warm upper ocean waters that must flow northward to replace them.
Considerable evidence suggests that this strength of the Atlantic Ocean overturning has varied in the past, and that these variations were linked to large climatic changes in the North Atlantic region.
Much of our current work is directed towards reconstructing these past changes for key intervals in the past, and understanding the causes and climatic impacts of these changes.
Select Related Publications:
Curry, W. B. and Oppo, D. W., Glacial water mass geometry and the distribution of d13C of SCO2 in the Western Atlantic Ocean, Paleoceanography, 20, PA1017, doi:10.1029/2004PA001021, 2005.
Raymo, M.E., D.W. Oppo, B.P. Flower, D.A. Hodell, J. F. McManus, K.A. Venz, K.F. Kleiven, K. McIntyre, Stability of North Atlantic water masses in face of pronounced natural climate variability, Paleoceanography, 19, doi:10.1029/2003PA000921, 2004.
Came, R. E., D. W. Oppo, W. B. Curry, Atlantic Ocean circulation during the Younger Dryas: insights from a new Cd/Ca record from the western subtropical South Atlantic, Paleoceanography, 18, doi:10.1029/2003PA000888, 2003.
Oppo, D. W., J. F. McManus, and J. L. Cullen, Deepwater variability in the Holocene Epoch, Nature 422, 277-278, 2003.
Marchitto, T. M., Jr., D. W. Oppo, and W. B. Curry, Paired benthic foraminiferal Cd/Ca and Zn/Ca evidence for a greatly increased presence of Southern Ocean Water in the glacial North Atlantic, Paleoceanography, 17, doi:10.1029/2000PA000598, 2002.
Oppo, D. W., L. D. Keigwin, J. F. McManus, and J. L. Cullen, Evidence for millennial scale variability during Marine Isotope Stage 5 and Termination II, Paleoceanography, 16, 280-292, 2001.
Oppo, D. W., and M. Horowitz, Glacial deepwater hydrography: South Atlantic benthic Cd/Ca and d13C evidence, Paleoceanography, 15, 147-160, 2000.
Oppo, D.W. and S. J. Lehman, Suborbital timescale variability of North Atlantic deep water during the past 200,000 years, Paleoceanography, 10, 901-910,1995.
Oppo, D. W., M. E. Raymo, G. P. Lohmann, A. C. Mix, J. D. Wright, and W. B. Prell, A d13C record of Upper North Atlantic Deep Water during the past 2.6 myrs, Paleoceanography, 10, 395-414, 1995.
Oppo, D. W., and Y. Rosenthal, Cd/Ca Changes in a deep Cape Basin core over the past 730,000 years: Response of circumpolar deepwater variability to northern hemisphere ice sheet melting?, Paleoceanography, 9, 661-675, 1994.
Oppo, D.W. and S. J. Lehman, Mid-depth circulation of the subpolar North Atlantic during the Last Glacial Maximum, Science 259, 1148-1152, 1993.
Oppo, D. W., and R. G. Fairbanks, Atlantic ocean thermohaline circulation over the last 150,000 years: Relationship to climate and atmospheric CO2. Paleoceanography, 5, 277-288, 1990.
Oppo, D. W., R. G. Fairbanks, A. L. Gordon, N. J. Shackleton, Late Pleistocene Southern Ocean d13C Variability. Paleoceanography, 5, 43-54, 1990.
Oppo, D. W., and R. G. Fairbanks, Variability in the deep and intermediate water circulation of the Atlantic Ocean: Northern Hemisphere modulation of the southern ocean. Earth and Planet. Sci. Letts., 86, 1-15, 1987.