Southeast Pacific ODP1233 High Resolution Termination 1 Alkenone SST Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE CONTRIBUTORS WHEN USING THIS DATA!!!!! NAME OF DATA SET: Southeast Pacific ODP1233 High Resolution Termination 1 Alkenone SST Data LAST UPDATE: 8/2007 (Original receipt by WDC Paleo) CONTRIBUTOR: Frank Lamy, Alfred-Wegener-Institute IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2007-073 SUGGESTED DATA CITATION: Lamy, F., et al. 2007. Southeast Pacific ODP1233 High Resolution Termination 1 Alkenone SST Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2007-073. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Lamy, F., J. Kaiser, H.W. Arz, D. Hebbeln, U. Ninnemann, O. Timm, A. Timmermann, and J.R. Toggweiler. 2007. Modulation of the bipolar seesaw in the Southeast Pacific during Termination 1. Earth and Planetary Science Letters, Vol. 259, pp. 400–413. ABSTRACT: The termination of the last ice age (Termination 1; T1) is crucial for our understanding of global climate change and for the validation of climate models. There are still a number of open questions regarding for example the exact timing and the mechanisms involved in the initiation of deglaciation and the subsequent interhemispheric pattern of the warming. Our study is based on a well-dated and high-resolution alkenone-based sea surface temperature (SST) record from the SE-Pacific off southern Chile (Ocean Drilling Project Site 1233) showing that deglacial warming at the northern margin of the Antarctic Circumpolar Current system (ACC) began shortly after 19,000 years BP (19 kyr BP). The timing is largely consistent with Antarctic ice-core records but the initial warming in the SE-Pacific is more abrupt suggesting a direct and immediate response to the slowdown of the Atlantic thermohaline circulation through the bipolar seesaw mechanism. This response requires a rapid transfer of the Atlantic signal to the SE-Pacific without involving the thermal inertia of the Southern Ocean that may contribute to the substantially more gradual deglacial temperature rise seen in Antarctic ice-cores. A very plausible mechanism for this rapid transfer is a seesaw-induced change of the coupled ocean–atmosphere system of the ACC and the southern westerly wind belt. In addition, modelling results suggest that insolation changes and the deglacial CO2 rise induced a substantial SST increase at our site location but with a gradual warming structure. The similarity of the two-step rise in our proxy SSTs and CO2 over T1 strongly demands for a forcing mechanism influencing both, temperature and CO2. As SSTs at our coring site are particularly sensitive to latitudinal shifts of the ACC/southern westerly wind belt system, we conclude that such latitudinal shifts may substantially affect the upwelling of deepwater masses in the Southern Ocean and thus the release of CO2 to the atmosphere as suggested by the conceptual model of [Toggweiler, J.R., Rusell, J.L., Carson, S.R., 2006. Midlatitude westerlies, atmospheric CO2, and climate change during ice ages. Paleoceanography 21. doi:10.1029/2005PA001154]. GEOGRAPHIC REGION: Southeast Pacific PERIOD OF RECORD: Termination 1, 10-25 kyr BP FUNDING SOURCE: Deutsche Forschungsgemeinschaft (DFG). DESCRIPTION: High resolution alkenone SST record from the SE-Pacific (ODP Site 1233) covering Termination 1 (10-25 kyr BP). ODP1233: Site 1233 (41°00'S, 74°27'W, 838m water depth) DATA: 1. 14C Ages obtained by Accelerator Mass Spectrometry dating of mixed planktonic foraminifera samples (primarily Globigerinoides bulloides and Neogloboquadrina pachyderma), performed at the Leibniz-Labor AMS facility in Kiel, Germany. Cal.Age Cal.Age Cal.Age Sedimentation Rates(m/kyr) Lab. ID Depth 14Cage Err+/- CalPal Err INTCAL Err Fairbanks Err CalPal INTCAL Fairbanks KIA 2145 12.94 8.94 0.08 10.05 0.13 10.05* 0.13 10.05 0.13 1.88 1.88 1.88 KIA 2961 14.21 9.47 0.043 10.75 0.1 10.72* 0.07 10.72 0.08 1.81 1.9 1.9 KIA 2147 17.01 10.4 0.07 12.33 0.17 12.33* 0.18 12.33 0.16 1.77 1.74 1.74 KIA 2144 20.22 11.88 0.07 13.76 0.11 13.75* 0.06 13.83 0.05 2.24 2.26 2.14 KIA 2961 21.39 12.78 0.055 15.26* 0.11 15.09 0.06 15.02 0.07 0.78 0.87 0.98 KIA 2961 ++ 23.69 13.09 0.06 ++ 16.13* 0.4 ++ 15.47 0.09 ++ 15.41 0.08 ++ 2.64 6.05 5.9 ++ KIA 2144 25.1 14.02 0.11 17.35* 0.07 16.72 0.14 16.73 0.19 1.16 1.13 1.07 KIA 2961 27.97 15.35 0.07 18.68 0.08 18.73* 0.05 18.65 0.04 2.16 1.43 1.49 KIA 1969 29.81 16.67 0.11 19.93 0.27 19.77* 0.14 19.81 0.16 1.47 1.77 1.59 KIA 2961 31.47 17.41 0.09 20.91 0.38 20.54* 0.1 20.61 0.15 1.69 2.16 2.08 KIA 1969 33.51 18.12 0.125 21.87 0.2 21.57* 0.24 21.68 0.22 2.13 1.98 1.91 KIA 1969 36.56 19.34 0.135 23.1 0.27 23* 0.26 23.09 0.29 2.48 2.13 2.16 KIA 1970 39.5 20.68 0.15 24.64 0.23 24.9* 0.3 24.73 0.27 1.91 1.55 1.79 Shown are the calendar ages and resulting linear sedimentation-rates based on the CalPal_SFCP_2005 (www.calpal.de) primarily based on the GISP2-synchronised Cariaco basin record (Hughen et al., 2004), INTCAL04 (Reimer et al., 2004), and the most recent Fairbanks U/Th-based calibration curve (Fairbanks et al., 2005). Marked with ++ is one dating that is affected by the radiocarbon plateau shown by the CalPal_SFCP_2005 calibration curve (see Fig. 2 and discussion in 3.2.). * mark calibrated ages used for the final age model. 2. SST Data ODP Site 1233 Column 1: Depth (mcd) Column 2: Calendar age (kyr) Column 3: SST (°C) Depth Cal.age SST 12.91 10.03406 15.84 13.15 10.16079 15.39 13.47 10.32961 15.84 13.59 10.39291 15.84 13.83 10.51953 14.9 14.19 10.70945 15.95 14.55 10.9155 15.62 14.8 11.05925 15.58 15.04 11.19725 15.61 15.16 11.26625 15.46 15.28 11.33525 14.85 15.4 11.40425 15.45 15.52 11.47325 15.3 15.64 11.54225 15.34 15.76 11.61125 15.3 15.88 11.68025 14.89 16 11.74925 14.95 16.12 11.81825 15.05 16.24 11.88725 15.17 16.36 11.95625 14.94 16.48 12.02525 14.79 16.6 12.09425 14.79 16.72 12.16325 15.42 16.84 12.23225 14.72 16.96 12.30125 14.55 17.08 12.36097 14.29 17.44 12.52022 14.06 17.68 12.62639 14.27 17.8 12.67947 13.88 17.92 12.73256 13.25 18.04 12.78564 13.47 18.16 12.83872 13.28 18.28 12.89181 13.29 18.4 12.94489 13.44 18.52 12.99798 13.43 18.64 13.05106 13.24 18.76 13.10414 13.37 18.88 13.15723 13.37 19 13.21031 13.85 19.12 13.2634 13.06 19.24 13.31648 13.55 19.48 13.42265 13.27 19.6 13.47573 13.25 19.72 13.52882 13.24 19.84 13.5819 13.22 19.96 13.63498 13.29 20.08 13.68807 12.76 20.2 13.74115 13.15 20.32 13.87906 13.37 20.44 14.03393 13.63 20.56 14.1888 13.59 20.69 14.35658 12.95 20.81 14.51145 13.31 20.93 14.66633 13.12 21.05 14.8212 12.72 21.17 14.97607 13.2 21.41 15.26756 13.31 21.53 15.31296 13.73 21.65 15.35835 13.49 21.72 15.38483 13.32 21.84 15.43022 13.52 21.96 15.47561 13.42 22.08 15.521 13.27 22.2 15.56639 13.09 22.32 15.61178 13.24 22.44 15.65717 13.26 22.56 15.70257 12.8 22.68 15.74796 13.23 22.8 15.79335 13.6 22.92 15.83874 13.23 23.04 15.88413 13.43 23.19 15.94087 12.8 23.31 15.98626 12.6 23.43 16.03165 13.13 23.55 16.07704 13.21 23.67 16.12243 12.98 23.79 16.21653 13.11 23.91 16.32035 12.68 24.03 16.42418 12.86 24.15 16.52801 13.37 24.27 16.63184 12.75 24.39 16.73567 13.65 24.51 16.8395 13.08 24.63 16.94333 12.59 24.75 17.04716 12.1 24.87 17.15099 12.2 24.99 17.25482 12.29 25.11 17.35481 12.62 25.17 17.38366 12.77 25.29 17.44136 13.07 25.41 17.49906 12.56 25.47 17.52791 12.35 25.53 17.55676 12.83 25.65 17.61446 12.93 25.77 17.67216 12.3 25.91 17.73948 11.47 26.03 17.79718 11.51 26.15 17.85488 11.15 26.27 17.91258 11.64 26.39 17.97028 11.35 26.51 18.02798 11.16 26.63 18.08568 10.62 26.75 18.14338 10.99 26.87 18.20108 10.06 26.99 18.25878 10.4 27.11 18.31648 11.07 27.23 18.37418 10.72 27.35 18.43188 10.86 27.47 18.48958 10.34 27.59 18.54728 9.95 27.71 18.60498 9.8 27.83 18.66268 9.07 27.95 18.72038 8.99 28.07 18.78652 8.27 28.18 18.8487 9.16 28.3 18.91652 9.02 28.42 18.98435 9.42 28.54 19.05217 9.73 28.66 19.12 9.15 28.78 19.18783 9.4 28.9 19.25565 9.29 29.02 19.32348 8.89 29.38 19.52696 9.67 29.86 19.79319 9.51 30.22 19.96018 11.03 30.46 20.07151 9.62 30.82 20.23849 10.31 31.21 20.4194 9.84 31.57 20.59049 10.53 31.93 20.77226 9.95 32.31 20.96412 10.13 32.68 21.15093 9.92 33.04 21.3327 10.25 33.28 21.45387 10.15 33.4 21.51446 9.53 33.64 21.63095 10.4 34 21.79974 9.31 34.12 21.856 9.44 34.48 22.02479 10.49 34.84 22.19357 9.01 35.2 22.36236 10.1 35.44 22.47489 7.78 35.56 22.53115 7.96 35.92 22.69993 9.1 36.28 22.86872 9.61 36.64 23.0517 9.8 36.87 23.20034 9.96 37.23 23.43299 9.17 37.52 23.62041 8.73 37.77 23.78197 8.98 38.01 23.93708 9.61 38.25 24.09218 10.28 38.49 24.24728 10.64 38.61 24.32483 10.47 38.85 24.47993 10.77 39.09 24.63503 10.83 39.22 24.71905 10.98 39.46 24.87415 11.19 39.7 24.95269 9.82 39.82 24.98431 10.91