noaa-recon-10355 North Atlantic DSDP607 Plio-Pleistocene Alkenone SST Reconstructions Lawrence, K.T.; Sosdian, S.M.; White, H.E.; Rosenthal, Y. North Atlantic DSDP607 Plio-Pleistocene Alkenone SST Reconstructions 2011-01-05 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/10355 Investigator K.T. Lawrence Investigator S.M. Sosdian Investigator H.E. White Investigator Y. Rosenthal earth science paleoclimate climate reconstructions|paleoceanography age,null,null,calendar kiloyear before present,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography sample identification,null,null,null,null,climate reconstructions|paleoceanography,null,null,C,Site Section Interval (cm) earth science paleoclimate climate reconstructions|paleoceanography depth,null,null,meter,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate paleoceanography alkenone unsaturation index Uk37 prime,null,null,dimensionless,null,paleoceanography,null,null,N,null earth science paleoclimate reconstructions sea surface temperature geoscientificInformation Sea Surface Temperature Reconstruction 3202320 cal yr BP 247830 cal yr BP Complete 41.000019 41.000019 -32.950122 -32.950122 -3427 -3427 Ocean Atlantic Ocean North Atlantic Ocean DSDP 607>LATITUDE 41.000019>LONGITUDE -32.950122 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Lawrence, K.T., S. Sosdian, H.E. White, and Y. Rosenthal. 2010. North Atlantic climate evolution through the Plio-Pleistocene climate transitions. Earth and Planetary Science Letters, Vol. 300, Issues 3-4, 1 December 2010, pp. 329-342. doi:10.1016/j.epsl.2010.10.013

During the Plio-Pleistocene, the Earth witnessed the growth of large northern hemisphere ice sheets and profound changes in both North Atlantic and global climate. Here, we present a ~3.2 Myr long, orbitally-resolved alkenone sea surface temperature (SST) record from Deep Sea Drilling Project (DSDP) Site 607 (41°N, 33°W, water depth 3427 m) in the North Atlantic Ocean. We employ a multi-proxy approach comparing these new observations with existing bottom water temperature (BWT) and stable isotope time series from the same site and SST time series from other sites, shedding new light on Plio-Pleistocene climate change. North Atlantic temperature records show a long-term cooling with two major steps occurring during the late Pliocene (3.1 to 2.4 Ma) and the mid-Pleistocene (1.5 to 0.8 Ma), closely timed with intervals of major change in northern hemisphere ice sheets. Existing evidence suggests that the late Pliocene cooling may have been caused by a thresholded response to secular changes in atmospheric carbon dioxide (CO2). While an explanation for the mid-Pleistocene cooling may involve glacial-interglacial changes in atmospheric CO2, it seems to also require a change in the behavior of the ice sheets themselves. North Atlantic climate responses were closely phased with benthic oxygen isotope (d18O) changes during the "41 kyr world," indicating a strong common northern hemisphere high latitude imprint on North Atlantic climate signals. After the mid- Pleistocene transition (MPT), North Atlantic SST records and the Site 607 benthic carbon isotope (d13C) record are more closely phased with d18O, whereas BWT significantly leads d18O in the 100 kyr band, suggesting a shift from a northern to a southern hemisphere influence on North Atlantic BWT. We propose that the expansion of the West Antarctic ice sheet (WAIS) across the MPT increased the production and export of Antarctic Bottom Water from the Southern Ocean and subsequently controlled its incursion into the North Atlantic, especially during glacial intervals. It follows that the early 100 kyr response of BWT implies an early response of the WAIS relative to the northern hemisphere deglaciation. Thus, in the "100 kyr world," both northern hemisphere and southern hemisphere processes affect climate conditions in the North Atlantic Ocean. STUDY NOTES: This dataset consists of North Atlantic Alkenone Sea Surface Temperature estimates from DSDP Site 607 from 3.2 Ma to 0.25 Ma at ~3-4 kyr resolution. Alkenones are lipid compounds created by a few species of ocean surface dwelling algae. The alkenone unsaturation index (Uk'37 = [C37:2]/[C37:2] + [C37:3]) has been linearly calibrated to organism growth temperature and thus has been used as a means of estimating past ocean surface temperatures [Brassell, et al., 1986; Prahl and Wakeham, 1987]. We use the Prahl et al. [1988] calibration to generate estimates of past sea surface temperatures.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lawrence2010/lawrence2010.xls GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lawrence2010/lawrence2010.txt USA/NOAA DIF Version 9.8.4 2019-05-06 2019-05-06