Monday, April 30, 2007

North Atlantic Sediments.....con't.

I found this almost immediately......hmmmmm.......where the heck is the carbon dioxide causing the warming coming from? Or could it be CO2 plays little if any role?
Peter


Nature 365, 143 - 147 (09 September 1993); doi:10.1038/365143a0
Correlations between climate records from North Atlantic sediments and Greenland ice
Gerard Bond*, Wallace Broecker*, Sigfus Johnsen†‡, Jerry McManus*, Laurent Labeyrie§, Jean Jouzel¶ & Georges Bonani
*Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA†The Niehls Bohr Institute, Department of Geophysics, University of Copenhagen, Haraldsgade 6, DK-2200, Copenhagen N, Denmark‡Science Institute, Department of Geophysics, University of Iceland, Dunghaga 3, IS-107 Reykjavik, Iceland§CFR Laboratoire mixte CNRS-CEA, Domaine du CNRS, 91198, Gif-sur-Yvette, Cedex, France¶Laboratorie de Modération du Climat et de I'Environnement, CEA/DSM, CE Saclay 91191, FranceLaboratorie de Glaciologie et Géophysique de 1'Environnement, CNRS, BP96, 38402 St. Martin d'Hères Cedex, France£Institute fur Mittelenergiephysik, ETH Honggerberg, CH-8093 Zurich, Switzerland
OXYGEN isotope measurements in Greenland ice demonstrate that a series of rapid warm-cold oscillations—called Dansgaard–Oeschger events—punctuated the last glaciation1. Here we present records of sea surface temperature from North Atlantic sediments spanning the past 90 kyr which contain a series of rapid temperature oscillations closely matching those in the ice-core record, confirming predictions that the ocean must bear the imprint of the Dansgaard–Oeschger events2,3. Moreover, we show that between 20 and 80 kyr ago, the shifts in ocean-atmosphere temperature are bundled into cooling cycles, lasting on average 10 to 15 kyr, with asymmetrical saw-tooth shapes. Each cycle culminated in an enormous discharge of icebergs into the North Atlantic (a 'Hein-rich event'4,5), followed by an abrupt shift to a warmer climate. These cycles document a previously unrecognized link between ice sheet behaviour and ocean–atmosphere temperature changes. An important question that remains to be resolved is whether the cycles are driven by external factors, such as orbital forcing, or by inter-nal ice-sheet dynamics.

References
1.
Dansgaard, W. et al. Nature 364, 218−220 (1993). Article ISI
2.
Broecker, W. S. et al. Quat. Res. 30, 1−6 (1988). Article
3.
Broecker, W. S., Bond, G. & Klas, M. Paleoceanogr. 5(4), 469−477 (1990).
4.
Bond, G. et al. Nature 360, 245−249 (1992). Article ISI
5.
Broecker, W. S., Bond, G., Klas, M., Clark, E. & McManus, J. Clim. Dynamics 6, 265−273 (1992).
6.
Bé, A. W. H. & Tolderlund, D. S. Micropaleontology of Oceans (eds Funnell, B. M. & Riedel, W. R.) 105−149 (Cambridge Univ. Press, 1971).
7.
Kellogg, T. B. Boreas 9, 115−137 (1980). ISI
8.
Broecker, W. S. Paleoceanogr. 3(1), 1−19 (1988).
9.
Lehman, S. J. & Keigwin, L. D. Nature 356, 757−762 (1992). Article ISI
10.
Karpuz, N. C. & Jansen, E. Paleoceanogr. 7(4), 499−520 (1992).
11.
Bond, G., Broecker, W., Lotti, R. & McManus, J. in Start of a Glacial (eds Kukla, G. J. & Went, E.) 185−205 (Springer, Berlin, 1992).
12.
Johnsen, S. J. et al. Nature 359, 311−313 (1992). Article ISI
13.
Alley, R. B. et al. Nature 362, 527−529 (1993). Article ISI
14.
Bard, E., Arnold, M., Fairbanks, R. G. & Hamelin, B. Radiocarbon 3(1), 191−199 (1993).
15.
Martinson, D. G. et al. Quat. Res. 27, 1−29 (1987). Article ISI ChemPort
16.
Dansgaard, W., White, J. W. C. & Johnsen, S. J. Nature 339, 532−533 (1989). Article ISI
17.
Taylor, K. C. et al. Nature 361, 432−436 (1993). Article ISI
18.
Heinrich, H. Quat. Res. 29, 142−152 (1988). Article ISI
19.
Ruddiman, W. F. & McIntyre, A. Paleogeogr. Palaeoclimatol. Palaeoecol. 35, 145−214 (1981). ChemPort
20.
Duplessy, J-C. Labeyrie, L., Juillet-LeClerc, A. & Duprat, J. in The Last Deglaciation: Absolute and Radiocarbon Chronologies (eds Bard, E. & Broecker, W. S.) 201−208 (Springer, Berlin, 1992).
21.
Andrews, J. T., Tedesco, K., Briggs, W. M. & Evans, L. W. Can. J. Earth Sci. (in the press).
22.
MacAyeal, D. R. Nature 359, 29−32 (1992). Article ISI
23.
Ruddiman, W. F. in Northern America and Adjacent Oceans during the Last Deglaciation: The Geology of North America (eds Ruddiman, W. F. & Wright, H. E. Jr) 137−154 (Geol. Soc. of Am, Boulder, 1987).
24.
Sancetta, C., Imbrie, J. & Kipp, N. G. Quat. Res. 3, 110−116 (1973). Article
25.
Woillard, G. & Mook, W. G. Science 215, 159−161 (1982). ISI ChemPort
26.
Shakleton, N. J., Imbrie, J. & Hall, M. A. Earth planet. Sci. Lett. 65, 233−244 (1983). Article ISI ChemPort
27.
Bloom, A. L., Broecker, W. S., Chappell, J. M. A., Matthews, R. K. & Mesolella, K. J. Quat. Res. 4, 185−205 (1974). Article ISI ChemPort

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