Benguela Current GeoB 1023-5 21ka Alkenone SST Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: Benguela Current GeoB 1023-5 21ka Alkenone SST Reconstruction LAST UPDATE: 8/2009 (Original receipt by WDC Paleo) CONTRIBUTOR: Jung-Hyun Kim, Royal Netherlands Institute for Sea Research (NIOZ). IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-090 WDC PALEO CONTRIBUTION SERIES CITATION: Kim, J.-H., et al. 2009. Benguela Current GeoB 1023-5 21ka Alkenone SST Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-090. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Kim, J.-H., R.R. Schneider, P.J. Mueller, and G. Wefer. 2002. Interhemispheric comparison of deglacial sea-surface temperature patterns in Atlantic eastern boundary currents. Earth and Planetary Science Letters, Vol. 194, pp. 383-393. ABSTRACT: Sediment core GeoB 1023-5 from the eastern South Atlantic was investigated at high temporal resolution for variations of sea-surface temperature (SST) during the past 22 kyr, using the alkenone (UK'37) method. SSTs increased by 3.5°C from about 18°C during the Last Ice Age (21 ± 2 cal kyr BP) to about 21.5°C at 14.5 cal kyr BP. This warming trend associated with the deglaciation phase was followed by a cooling event with lowest SSTs near 20°C, persisting for about 1000 years between 13 and 12 cal kyr BP. The SSTs then continued to increase to about 22.5°C at the Holocene climatic optimum at 7 cal kyr BP, and decreased again during the Late Holocene to a core-top value of 19.8°C that is comparable to modern annual mean SST values. When compared with alkenone SST records from the eastern North Atlantic, our SST record indicates continuous warming throughout the deglaciation phase in the Benguela Current, while its northern counterpart, the Canary Current, experienced prominent cooling during 'Heinrich Event 1'(H1). On the other hand, for the time period corresponding to the 'Younger Dryas' (YD) cooling event, the Benguela SST record exhibits a cold-temperature interval that corresponds to that observed in the eastern North Atlantic SST records. This observation suggests that interhemispheric climate response in Atlantic eastern boundary current systems was different with respect to the two abrupt climate events associated with Termination I. For the H1, the eastern South Atlantic SST record strongly supports the hypothesis that an 'anti-phase' thermal behavior in South Atlantic surface waters was forced by the slowdown of the North Atlantic Deep Water formation during cold spells in the North Atlantic. In contrast, the abrupt cooling in the eastern South Atlantic coincident with the YD period was probably induced by more vigorous global atmospheric circulation, enhancing the upwelling intensity in both eastern boundary current systems. This atmospheric control may have overridden any effect caused by changes in thermohaline circulation on the South Atlantic SSTs during the YD, which leads to the assumption that the thermohaline circulation was already much closer to its interglacial mode during the YD than during the H1. ADDITIONAL REFERENCE: Mueller, P.J., G. Kirst, G. Ruhland, I. von Storch, and A. Rosell-Mele. 1998. Calibration of the alkenone palaeotemperature index UK'37 based on core-tops from the eastern South Atlantic and the global ocean (60°N-60°S). Geochim. Cosmochim. Acta 62, 1757-1772. GEOGRAPHIC REGION: Eastern South Atlantic PERIOD OF RECORD: 21KYrBP - present FUNDING SOURCES: The Graduiertenkolleg Program at the Fachbereich Geowissenschaften and the Sonderforschungsbereich 261 (SFB 261), both at the University of Bremen and sponsored by the Deutsche Forschungsgemeinschaft (DFG). DESCRIPTION: Eastern South Atlantic (Angola Basin, Benguela Current) core GeoB 1023-5 alkenone (UK'37) data and Sea Surface Temperature (SST) reconstruction for the last 21 KYr. SST calculated by the core-top calibration of Mueller et al. 1998 [SST=(UK'37-0.044)/0.033]. Core GeoB 1023-5, eastern Angola Basin: 17°09.5'S, 11°00.5'E, water depth 1978 m. DATA: Alkenone SST's for core GeoB 1023-5 Column 1: Depth (m) Column 2: Age (ka BP) Column 3: Sedimentation Rate (cm/ka) Column 4: UK'37 Column 5: Sea Surface Temperature, °C Depth Age SedRate UK`37 SST 0.08 0.31 26.01 0.716 20.36 0.13 0.5 26.01 0.719 20.45 0.18 0.69 26.01 0.743 21.18 0.23 0.88 26.01 0.738 21.03 0.28 1.08 26.01 0.74 21.09 0.33 1.27 26.01 0.738 21.03 0.38 1.46 26.01 0.75 21.39 0.43 1.72 19.11 0.751 21.42 0.48 1.98 19.11 0.757 21.61 0.53 2.25 19.11 0.752 21.45 0.58 2.51 19.11 0.752 21.45 0.63 2.77 19.11 0.743 21.18 0.68 3.03 19.11 0.753 21.48 0.73 3.29 19.11 0.757 21.61 0.78 3.55 19.11 0.751 21.42 0.82 3.76 19.11 0.757 21.61 0.88 4.08 19.11 0.762 21.76 0.93 4.34 19.11 0.766 21.88 0.98 4.6 19.11 0.751 21.42 1.03 4.86 19.11 0.763 21.79 1.08 5.12 19.11 0.765 21.85 1.13 5.39 19.11 0.753 21.48 1.18 5.65 19.11 0.768 21.94 1.23 5.91 19.11 0.773 22.09 1.28 6.17 19.11 0.777 22.21 1.33 6.39 26.4 0.783 22.39 1.38 6.58 26.4 0.775 22.15 1.43 6.77 26.4 0.769 21.97 1.48 6.96 26.4 0.774 22.12 1.53 7.15 26.4 0.767 21.91 1.58 7.34 26.4 0.764 21.82 1.63 7.53 26.4 0.764 21.82 1.68 7.71 26.4 0.766 21.88 1.73 7.9 32.93 0.767 21.91 1.78 8.05 32.93 0.768 21.94 1.83 8.2 32.93 0.765 21.85 1.88 8.35 32.93 0.759 21.67 1.93 8.5 32.93 0.758 21.64 1.98 8.66 32.93 0.764 21.82 2.03 8.81 32.93 0.756 21.58 2.08 8.96 32.93 0.754 21.52 2.13 9.11 32.93 0.758 21.64 2.18 9.26 32.93 0.746 21.27 2.23 9.41 32.93 0.759 21.67 2.28 9.57 32.93 0.747 21.3 2.33 9.72 32.93 0.737 21 2.38 9.87 32.93 0.741 21.12 2.43 10.02 32.93 0.749 21.36 2.48 10.17 32.93 0.743 21.18 2.53 10.33 32.93 0.744 21.21 2.58 10.48 32.93 0.745 21.24 2.63 10.63 32.93 0.727 20.7 2.68 10.78 32.93 0.733 20.88 2.73 10.93 32.93 0.729 20.76 2.78 11.09 32.93 0.725 20.64 2.83 11.15 75.98 0.736 20.97 2.88 11.22 75.98 0.726 20.67 2.93 11.28 75.98 0.74 21.09 2.98 11.35 75.98 0.731 20.82 3.03 11.41 75.98 0.727 20.7 3.08 11.48 75.98 0.723 20.58 3.13 11.55 75.98 0.728 20.73 3.18 11.61 75.98 0.727 20.7 3.23 11.68 75.98 0.722 20.55 3.28 11.74 75.98 0.72 20.48 3.33 11.81 75.98 0.72 20.48 3.38 11.87 75.98 0.71 20.18 3.43 11.94 75.98 0.708 20.12 3.48 12.01 75.98 0.714 20.3 3.53 12.07 75.98 0.699 19.85 3.58 12.14 75.98 0.707 20.09 3.63 12.2 75.98 0.707 20.09 3.68 12.27 75.98 0.703 19.97 3.73 12.34 75.98 0.701 19.91 3.78 12.4 75.98 0.697 19.79 3.83 12.47 75.98 0.705 20.03 3.88 12.51 121.95 0.697 19.79 3.93 12.55 121.95 0.716 20.36 3.98 12.59 121.95 0.706 20.06 4.03 12.63 121.95 0.721 20.52 4.08 12.67 121.95 0.725 20.64 4.13 12.71 121.95 0.719 20.45 4.18 12.75 121.95 0.727 20.7 4.23 12.8 121.95 0.726 20.67 4.28 12.84 121.95 0.715 20.33 4.33 12.88 121.95 0.713 20.27 4.38 12.92 121.95 0.732 20.85 4.43 12.96 121.95 0.722 20.55 4.48 13 121.95 0.736 20.97 4.53 13.04 121.95 0.724 20.61 4.58 13.08 121.95 0.725 20.64 4.63 13.12 121.95 0.748 21.33 4.68 13.16 121.95 0.717 20.39 4.73 13.21 121.95 0.729 20.76 4.78 13.25 121.95 0.725 20.64 4.83 13.29 121.95 0.73 20.79 4.88 13.33 121.95 0.731 20.82 4.93 13.37 121.95 0.72 20.48 4.98 13.41 121.95 0.715 20.33 5.03 13.45 121.95 0.733 20.88 5.08 13.49 121.95 0.728 20.73 5.13 13.53 121.95 0.723 20.58 5.18 13.57 121.95 0.736 20.97 5.23 13.62 121.95 0.729 20.76 5.28 13.66 121.95 0.743 21.18 5.33 13.7 121.95 0.728 20.73 5.38 13.74 121.95 0.73 20.79 5.43 13.78 121.95 0.732 20.85 5.48 13.82 121.95 0.723 20.58 5.53 13.86 121.95 0.732 20.85 5.58 13.9 121.95 0.743 21.18 5.63 13.94 121.95 0.737 21 5.68 13.98 121.95 0.736 20.97 5.73 14.03 121.95 0.744 21.21 5.78 14.07 121.95 0.739 21.06 5.83 14.11 121.95 0.735 20.94 5.88 14.15 121.95 0.751 21.42 5.93 14.27 41.27 0.75 21.39 5.98 14.39 41.27 0.755 21.55 6.03 14.51 41.27 0.749 21.36 6.08 14.63 41.27 0.749 21.36 6.13 14.75 41.27 0.746 21.27 6.18 14.87 41.27 0.741 21.12 6.23 15 41.27 0.731 20.82 6.28 15.12 41.27 0.719 20.45 6.33 15.24 41.27 0.719 20.45 6.38 15.36 41.27 0.712 20.24 6.43 15.48 41.27 0.716 20.36 6.48 15.6 41.27 0.72 20.48 6.53 15.72 41.27 0.718 20.42 6.58 15.84 41.27 0.724 20.61 6.63 15.97 41.27 0.726 20.67 6.68 16.09 41.27 0.705 20.03 6.73 16.21 41.27 0.715 20.33 6.78 16.33 41.27 0.69 19.58 6.83 16.45 41.27 0.702 19.94 6.88 16.57 41.27 0.693 19.67 6.93 16.64 69.79 0.691 19.61 6.98 16.71 69.79 0.682 19.33 7.03 16.79 69.79 0.691 19.61 7.08 16.86 69.79 0.694 19.7 7.13 16.93 69.79 0.694 19.7 7.18 17 69.79 0.681 19.3 7.23 17.07 69.79 0.696 19.76 7.28 17.14 69.79 0.666 18.85 7.33 17.22 69.79 0.665 18.82 7.38 17.29 69.79 0.674 19.09 7.43 17.36 69.79 0.65 18.36 7.48 17.43 69.79 0.671 19 7.53 17.52 50.54 0.653 18.45 7.58 17.62 50.54 0.653 18.45 7.63 17.72 50.54 0.665 18.82 7.68 17.82 50.54 0.662 18.73 7.73 17.92 50.54 0.655 18.52 7.78 18.02 50.54 0.658 18.61 7.83 18.12 50.54 0.662 18.73 7.88 18.22 50.54 0.63 17.76 7.93 18.32 50.54 0.677 19.18 7.98 18.41 50.54 0.658 18.61 8.03 18.51 50.54 0.656 18.55 8.13 18.71 50.54 0.665 18.82 8.18 18.81 50.54 0.648 18.3 8.23 18.91 50.54 0.655 18.52 8.28 19.01 50.54 0.643 18.15 8.33 19.11 50.54 0.641 18.09 8.38 19.21 50.54 0.636 17.94 8.43 19.3 50.54 0.657 18.58 8.48 19.4 50.54 0.645 18.21 8.53 19.5 50.54 0.646 18.24 8.58 19.6 50.54 0.642 18.12 8.63 19.7 50.54 0.636 17.94 8.68 19.8 50.54 0.654 18.48 8.73 19.9 50.54 0.643 18.15 8.78 20 50.54 0.642 18.12 8.83 20.1 50.54 0.629 17.73 8.88 20.2 50.54 0.645 18.21 8.93 20.29 50.54 0.634 17.88 8.98 20.39 50.54 0.637 17.97 9.03 20.49 50.54 0.625 17.61 9.08 20.59 50.54 0.653 18.45 9.13 20.69 50.54 0.641 18.09 9.18 20.79 50.54 0.627 17.67 9.23 20.89 50.54 0.652 18.42 9.28 20.99 50.54 0.644 18.18 9.33 21.09 50.54 0.673 19.06 9.38 21.19 50.54 0.639 18.03