| PALEOCEANOGRAPHY |
Tropical Atlantic Alkenone SST Reconstruction for the last 29,000 years
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Ruehlemann, C., S. Mulitza, P J. Mueller, G. Wefer, and R. Zahn. 1999. Warming of the tropical Atlantic Ocean and slowdown
of thermohaline circulation during the last deglaciation. Nature, Vol. 402, 511 - 514.
| Data Coverage |
North: 12.08 * South: 12.08 |
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West: -61.25 * East: -61.25 |
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Altitude: -1299 m |
Start Year: 24540 14C yr BP
* End Year: 0 14C yr BP
Data: Please Cite Data Contributors!
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Summary: Evidence for abrupt climate changes on millennial and shorter timescales is widespread in marine and terrestrial climate records.
Rapid reorganization of ocean circulation is considered to exert some control over these changes, as are shifts in the concentrations
of atmospheric greenhouse gases. The response of the climate system to these two influences is fundamentally different: slowing
of thermohaline overturn in the North Atlantic Ocean is expected to decrease northward heat transport by the ocean and to
induce warming of the tropical Atlantic, whereas atmospheric greenhouse forcing should cause roughly synchronous global temperature
changes. So these two mechanisms of climate change should be distinguishable by the timing of surface-water temperature variations
relative to changes in deep-water circulation. Here we present a high-temporal-resolution record of sea surface temperatures
from the western tropical North Atlantic Ocean which spans the past 29,000 years, derived from measurements of temperature-sensitive
alkenone unsaturation in sedimentary organic matter. We find significant warming is documented for Heinrich event H1 (16,900-15,400
calendar years BP) and the Younger Dryas event (12,900-11,600 cal. yr BP), which were periods of intense cooling in the northern
North Atlantic. Temperature changes in the tropical and high-latitude North Atlantic are out of phase, suggesting that the
thermohaline circulation was the important trigger for these rapid climate changes.
More Info on Paleoceanography Data |
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Parameters: 37:2 alkenone concentration, relative to sediment dry weight; radiocarbon years before 1950AD; Sea Surface Temperature from Uk'37; Alkenone saturation index; 37:3 alkenone concentration, relative to sediment dry weight; delta O18 PDB (Globigerinoides ruber (pink))
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Complete XML Record: noaa-ocean-2649
(Last Revised: 2008-04-10 )
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DOC/NOAA/NESDIS/NCDC (National Climatic Data Center, NESDIS, NOAA, U.S. Department of Commerce )
325 Broadway, E/CC23
Boulder, CO 80305
USA
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| http://www.ncdc.noaa.gov/paleo/ |
| E-mail: bruce.a.bauer@noaa.gov |
| E-mail: paleo@noaa.gov |
Phone: 303-497-6280
Fax: 303-497-6513
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