Subpolar North Atlantic 2000 Year Alkenone SST Reconstructions ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: Please cite original reference when using these data, plus the data file URL and date accessed. NAME OF DATA SET: Subpolar North Atlantic 2000 Year Alkenone SST Reconstructions LAST UPDATE: 12/2011 (Original receipt by WDC Paleo) CONTRIBUTORS: Sicre, M.-A., I.R. Hall, J. Mignot, M. Khodri, U. Ezat, M.-X. Truong, J. Eiríksson, K.-L. Knudsen, J.-L. Turon, E. Jansen, and J. Jacob IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2011-153 WDC PALEO CONTRIBUTION SERIES CITATION: Sicre, M.-A., et al. 2011. Subpolar North Atlantic 2000 Year Alkenone SST Reconstructions. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2011-153. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Sicre, M.-A., I.R. Hall, J. Mignot, M. Khodri, U. Ezat, M.-X. Truong, J. Eiríksson, and K.-L. Knudsen. 2011. Sea surface temperature variability in the subpolar Atlantic over the last two millennia. Paleoceanography, 26, PA4218, doi:10.1029/2011PA002169. ABSTRACT: A decadal resolution time series of sea surface temperature (SST) spanning the last two millennia is reconstructed by combining a proxy record from a new sediment sequence with previously published data from core MD99-2275, north of Iceland. The alkenone based SST reconstruction is validated with historic observational data and compared to a new similar temporal resolution reconstruction obtained from sediment core RAPiD21-3K, in the subpolar North Atlantic. The two SST paleorecords show consistent multidecadal scale coolings throughout the interval and similar expressions during the contrasted climatic periods 'colloquially known' as the Medieval Climatic Anomaly (MCA) and Little Ice Age (LIA). In order to further understand the temporal and spatial SST variations and investigate the influence of natural forcings on the observed SST changes during the last millennium, we compare our time series to simulations using the Institut Pierre-Simon Laplace IPSLCM4-v2 climate model. This comparison highlights the potential importance of volcanism as a natural forcing driving coherent abrupt cooling events captured in the subpolar North Atlantic records. ADDITIONAL REFERENCES: Sicre, M.-A., J. Jacob, U. Ezat, S. Rousse, C. Kissel, P. Yiou, J. Eiríksson, K.L. Knudsen, E. Jansen, and J.-L. Turon. 2008a. Decadal variability of sea surface temperatures off North Iceland over the last 2000 yrs. Earth and Planetary Science Letters, Vol. 268, pp. 137-142. doi:10.1016/j.epsl.2008.01.011. Sicre, M.-A., P. Yiou, J. Eiríksson, U. Ezat, E. Guimbaut, I. Dahhaoui, K. L. Knudsen, E. Jansen, and J.-L. Turon. 2008b. A 4500-year reconstruction of sea surface temperature variability at decadal time scales off North Iceland. Quaternary Science Reviews, Vol. 27, pp. 2041-2047. doi:10.1016/j.quascirev. 2008.08.009. Knudsen, K.-L., J. Eiríksson, H. Jiang, and I. Jónsdóttir. 2009. Palaeoceanography and climate changes off north Iceland during the last millennium: Comparison of foraminifera, diatoms and ice-rafted debris with instrumental and documentary data, Journal of Quaternary Science, Vol. 24(5), pp. 457-468, doi:10.1002/jqs.1292. Eiríksson, J., K.-L. Knudsen, G. Larsen, J. Olsen, J. Heinemeier, H. B. Bartels-Jónsdóttir, H. Jiang, L. Ran, and L. A. Símonarson. 2011. Coupling of palaeoceanographic shifts and changes in marine reservoir ages off north Iceland through the last millennium. Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 302, pp. 95-108. doi:10.1016/j.palaeo.2010.06.002. GEOGRAPHIC REGION: Subpolar North Atlantic PERIOD OF RECORD: 2001 A.D. to 1 A.D. FUNDING SOURCES: LEFE program supported by INSU (Institut National des Sciences de l'Univers), CNRS, EU-PACLIVA project (Pattern of Climate Variability in the North Atlantic) funded by the European Union 5th Framework Programme (contract EVK2-2002-00143), Millennium project funded by the European Union 6th Framework Programme (contract EVK-CT-2006-017008), NERC RAPiD Climate Change Programme grant NER/T/S/2002/00436, ANR ESCARSEL project, THOR project funded by the European Community's 7th framework program (FP7/2007-2013) under grant agreement GA212643 (Thermohaline Overturning - at Risk (THOR), 2008-2012). DATA FILE URLS: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/sicre2011/sicre2011.txt ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/sicre2011/sicre2011.xls DESCRIPTION: Decadal resolution time series of sea surface temperature (SST) obtained from alkenone paleothermometry spanning the last two millennia. Data are from North Atlantic cores MD99-2275 and RAPiD 21-3K. MD99-2275 is located north of Iceland, in the polar front, and RAPiD 21-3K is located in the subpolar Atlantic, South of Iceland. The current MD99-2275 age model is constructed using eight geochemically identified tephra layers [Knudsen et al., 2009, Table 2], the 137Cs peak of maximum nuclear testing in 1963 A.D., and the top of undisturbed sediment according to 210Pb measurements. The top of the spliced cores at site MD99-2275 is assumed at 2006 ± 1 A.D, and estimation of age model uncertainties for the record has been published [Eiríksson et al., 2011]. Temporal resolution ranges from 2 to 4 years. This reconstruction extends to the present-day the decadal-scale alkenone based SST reconstruction earlier published by Sicre et al. [Earth Planet. Sci. Lett., 268, 137-142, doi:10.1016/j.epsl.2008.01.011, 2008a] and Sicre et al. [Quat. Sci. Rev., 27, 2041-2047, doi:10.1016/j.quascirev. 2008.08.009, 2008b] and now includes the 20th century. Overall, this MD99-2275 spliced record combines three sediment sequence reconstructions with different coring devices (piston, gravity and box) in a highly variable region thus represents a unique regional reconstruction benchmark. MD99-2275: 66°33'N, 17°42'W, 470 m water depth RAPiD 21-3K: 57°27.09'N, 27°54.53'W, 2630 m water depth DATA: 1. Spliced MD99-2275 alkenone SST Age(yrAD) T°C 2001 6.6 1998 6.3 1995 7.0 1993 7.3 1990 8.3 1987 6.9 1985 6.9 1982 6.2 1980 6.0 1977 6.6 1974 6.7 1972 6.3 1969 5.4 1967 6.2 1964 6.8 1960 7.0 1955 6.3 1950 6.8 1945 5.8 1942 6.8 1939 7.1 1936 6.9 1932 7.0 1929 7.2 1928 6.9 1925 6.5 1922 6.7 1918 6.7 1915 6.2 1912 6.7 1908 6.6 1905 6.8 1902 6.9 1898 7.1 1895 7.0 1893 7.0 1891 6.9 1889 8.3 1888 7.5 1886 6.9 1884 6.8 1883 7.2 1881 7.3 1880 7.1 1878 7.5 1876 6.9 1875 6.6 1872 7.5 1870 7.8 1868 6.5 1867 7.3 1865 7.7 1863 6.5 1860 7.7 1859 7.2 1857 7.9 1855 7.1 1854 6.5 1852 8.2 1850 6.3 1849 7.6 1847 7.1 1846 7.0 1844 6.9 1842 6.9 1841 7.0 1839 7.4 1837 6.4 1836 6.9 1834 7.3 1833 7.6 1831 8.1 1829 7.5 1828 7.8 1826 7.0 1825 7.2 1823 6.6 1821 7.2 1820 7.6 1818 7.9 1816 7.6 1815 7.7 1813 7.8 1812 7.6 1810 6.7 1808 7.1 1807 7.6 1805 7.1 1803 7.2 1802 7.6 1800 7.5 1798 8.2 1797 7.8 1795 7.6 1793 7.4 1791 7.5 1789 7.5 1787 7.4 1785 7.5 1783 7.3 1781 8.2 1779 7.3 1777 7.5 1776 7.6 1774 7.0 1772 6.6 1770 7.3 1768 7.2 1766 8.1 1764 6.8 1762 7.9 1760 8.5 1758 7.3 1756 6.5 1754 7.0 1752 7.9 1750 7.6 1748 7.3 1746 6.8 1744 6.8 1742 6.8 1740 7.2 1738 7.0 1737 7.5 1735 6.6 1733 7.3 1731 7.4 1729 7.3 1727 7.7 1725 7.8 1723 7.2 1721 7.8 1719 7.5 1717 7.5 1714 7.7 1711 7.6 1708 8.2 1705 8.0 1702 7.4 1699 8.0 1695 7.7 1692 7.8 1689 7.7 1686 7.8 1683 8.0 1680 6.0 1677 7.0 1674 7.0 1671 7.4 1668 7.6 1665 6.6 1662 8.1 1659 7.4 1655 7.6 1652 7.7 1649 8.1 1646 8.4 1643 8.2 1640 7.4 1637 7.8 1634 7.9 1631 7.7 1628 8.2 1625 7.8 1622 7.8 1619 7.4 1615 7.3 1612 7.5 1609 7.9 1606 8.8 1603 9.3 1600 8.7 1597 8.7 1594 8.3 1591 7.9 1588 6.7 1582 7.7 1579 7.7 1575 8.3 1572 7.9 1569 7.9 1566 7.7 1563 6.6 1560 8.0 1557 8.1 1554 8.3 1551 8.4 1548 8.3 1545 6.9 1542 5.9 1539 6.7 1535 8.2 1532 7.8 1529 7.8 1526 8.4 1523 8.3 1520 8.4 1517 7.6 1514 7.2 1511 8.6 1508 8.3 1505 8.2 1502 7.3 1499 7.6 1495 7.9 1492 7.7 1489 7.9 1486 7.6 1483 7.5 1480 7.5 1477 7.8 1475 8.5 1473 8.0 1470 9.5 1468 8.4 1466 8.6 1464 9.6 1461 8.7 1459 8.0 1457 8.9 1455 7.1 1452 7.7 1450 8.1 1448 8.4 1446 7.6 1444 8.2 1441 7.7 1439 7.8 1437 8.0 1435 7.3 1432 7.2 1430 7.6 1428 7.5 1426 7.6 1423 7.1 1421 6.9 1419 7.9 1417 8.1 1414 8.7 1412 9.3 1410 8.1 1406 7.5 1403 8.0 1399 7.5 1395 7.9 1392 8.4 1388 7.4 1384 7.7 1381 7.2 1377 7.4 1373 8.3 1370 7.5 1366 7.1 1362 7.8 1359 8.1 1355 7.3 1351 7.5 1348 7.9 1344 7.3 1340 7.5 1337 8.4 1333 7.8 1329 8.4 1326 8.5 1322 9.0 1318 8.8 1315 8.6 1311 8.3 1307 9.2 1304 8.7 1300 9.0 1295 10.0 1289 8.5 1284 8.5 1278 9.0 1273 9.2 1267 8.9 1262 8.2 1256 8.4 1251 7.3 1246 7.9 1240 8.6 1235 8.9 1229 9.2 1224 8.8 1218 8.9 1213 8.3 1207 9.0 1202 9.1 1197 9.4 1191 9.0 1186 9.0 1180 8.7 1175 9.3 1169 8.9 1164 9.1 1158 8.7 1153 8.6 1148 8.7 1142 8.8 1137 8.8 1131 8.9 1126 8.8 1120 8.8 1115 8.7 1109 8.7 1104 9.0 1099 9.1 1094 9.0 1089 9.0 1084 9.0 1079 8.9 1074 9.3 1069 8.7 1063 8.9 1058 8.8 1053 9.4 1048 8.8 1043 9.2 1038 9.1 1033 9.2 1028 8.9 1023 8.8 1018 9.7 1013 9.4 1008 9.1 1003 8.9 998 9.3 993 9.0 988 9.2 982 8.7 977 7.9 972 8.5 967 8.1 962 8.3 957 8.6 952 7.6 948 7.6 943 8.2 938 8.8 933 7.9 928 7.9 923 8.6 918 8.6 913 8.0 908 7.2 903 7.7 898 8.3 893 8.1 888 7.8 883 8.2 878 7.7 873 8.6 867 8.2 862 6.8 857 8.2 851 8.3 846 8.4 841 8.4 835 7.9 830 8.6 825 8.2 820 8.5 814 8.5 809 8.1 804 8.4 798 7.9 793 7.6 788 7.9 782 7.3 777 7.9 772 7.3 766 8.3 761 7.8 756 7.9 751 8.1 745 8.0 740 8.3 735 8.1 729 7.9 724 8.2 719 8.1 713 7.5 708 7.7 703 7.9 697 8.1 692 7.6 687 7.3 681 7.8 676 7.8 671 7.6 666 8.0 660 7.9 655 7.8 650 8.1 644 8.2 639 6.7 634 6.1 628 7.6 623 8.5 618 8.8 612 8.4 607 8.9 602 8.1 597 8.3 591 8.0 586 7.6 581 8.3 575 8.2 570 7.1 565 8.4 559 8.2 554 9.7 549 8.4 543 8.7 538 8.7 533 8.9 528 7.9 522 9.8 517 8.3 512 8.4 506 8.3 501 8.5 496 8.1 490 8.5 485 8.4 480 7.9 474 8.2 469 8.3 464 8.3 459 8.5 453 8.2 448 8.2 443 8.5 437 8.3 432 8.0 427 8.1 421 8.1 416 8.2 411 7.9 405 8.4 400 8.1 395 9.3 389 8.9 384 8.2 379 8.5 374 8.4 368 8.3 363 8.3 358 8.4 352 8.2 347 8.3 342 8.5 336 8.1 331 6.6 326 7.5 320 8.1 315 8.3 310 7.4 305 8.1 299 7.8 294 8.3 289 8.2 283 8.0 278 8.1 273 8.4 267 9.9 262 8.0 257 7.6 251 10.5 246 7.9 241 8.2 236 7.9 230 8.1 225 8.2 220 8.2 214 8.8 209 7.7 204 8.4 198 8.2 193 8.2 188 7.5 182 6.4 177 7.7 172 8.6 166 8.7 161 7.8 156 - 151 9.0 145 8.2 140 8.2 135 8.7 129 8.3 124 9.1 119 8.5 114 8.5 109 8.6 104 8.4 99 8.8 94 8.6 89 9.7 83 9.3 78 9.1 73 8.8 68 9.1 63 8.8 58 8.3 53 9.6 48 - 42 7.9 37 8.3 32 8.2 27 8.4 22 9.0 17 9.5 12 7.8 7 8.7 1 8.8 2. Sicre et al. 2011 RAPid 21-3K alkenone SST Age(yrAD) T°C 1968 11.9 1959 9.3 1950 10.2 1941 9.8 1932 10.4 1924 9.7 1915 10.0 1906 10.8 1897 9.8 1889 10.1 1880 10.0 1872 10.3 1863 10.8 1855 10.1 1846 10.8 1838 9.3 1813 9.7 1805 10.8 1788 10.4 1780 9.9 1772 9.4 1764 10.2 1748 10.2 1740 10.7 1732 10.6 1724 10.8 1716 10.2 1708 10.7 1700 10.8 1692 10.6 1677 10.3 1661 11.7 1654 9.8 1646 11.7 1638 9.7 1631 9.7 1623 9.9 1616 9.9 1608 9.8 1601 9.7 1593 9.9 1586 9.5 1578 9.5 1571 9.4 1564 9.7 1556 9.7 1549 9.8 1542 10.1 1534 10.1 1527 10.0 1520 9.7 1513 10.4 1506 9.6 1499 12.9 1491 10.7 1484 10.2 1477 9.6 1470 10.4 1463 9.1 1456 10.9 1449 13.3 1442 10.8 1435 10.4 1428 10.2 1421 10.1 1414 9.1 1408 9.7 1401 9.9 1394 10.6 1387 10.1 1380 9.5 1373 10.3 1367 10.0 1360 8.9 1353 9.7 1347 10.0 1340 9.4 1333 9.8 1326 9.7 1320 9.6 1313 10.2 1307 10.3 1300 10.5 1293 10.0 1287 10.3 1280 10.4 1274 10.1 1267 9.9 1261 10.4 1254 10.1 1248 9.7 1241 10.1 1235 10.4 1228 9.4 1222 10.9 1215 10.4 1209 10.9 1202 9.6 1196 11.2 1190 11.4 1183 9.9 1177 10.4 1171 10.7 1164 10.8 1158 10.7 1152 10.2 1145 11.3 1139 11.1 1133 11.1 1126 10.4 1114 10.4 1107 10.6 1101 10.3 1095 13.2 1089 10.6 1082 9.8 1076 10.6 1070 10.2 1064 10.3 1057 10.3 1051 10.6 1045 10.3 1039 9.5 1032 11.3 1026 10.5 1020 10.3 1014 10.1 1008 10.1 1001 7.7 995 9.3 989 11.3 983 10.0 977 10.3 970 10.5 964 10.4 958 10.1 952 10.6 946 10.7 939 9.6 933 10.7 927 10.4 921 10.5 915 10.9 908 10.6 902 10.7 896 10.3 890 10.5 883 10.3 877 10.6 871 10.2 865 10.6 852 10.6 846 10.4 840 10.2 834 10.6 827 10.9 821 10.6 815 10.3 809 10.3 802 10.0 796 9.6 790 11.1 777 10.1 771 10.3 764 10.2 758 9.9 752 9.3 745 10.2 739 10.1 733 10.0 726 9.3 720 10.4 714 10.3 707 10.2 701 10.2 688 9.3 681 10.3 675 10.3 669 10.3 662 10.8 656 9.8 649 10.6 643 10.6 636 10.2 629 10.7 623 10.4 616 10.9 610 10.4 603 10.3 596 9.1 590 9.4 583 10.5 577 9.7 570 9.9 563 8.7 556 10.5 550 11.0 543 11.5 536 10.3 529 10.8 523 9.6 516 10.1 509 10.3 502 10.3 495 8.9 488 9.6 481 10.0 474 10.3 468 10.7 461 10.2 454 10.4 447 10.7 440 10.8 432 10.6 425 10.5 418 10.4 411 10.9 404 10.8 397 10.5 390 10.3 382 10.9 375 10.1 368 11.0 361 11.2 353 10.8 346 10.9 339 10.5 331 11.0 324 11.1 316 11.0 309 10.5 301 10.9 294 11.3 286 10.7 279 10.8 271 10.8 264 10.1 256 10.7 248 10.5 241 10.7 233 10.8 225 10.8 217 10.4 209 10.9 202 10.9 194 10.4 178 10.5 170 10.5 162 11.5 154 11.0 146 10.7 138 10.8 130 10.9 121 10.6 113 10.2 105 10.7 97 10.5 88 10.5 80 10.3 72 11.0 63 10.7 55 10.4 46 10.4 38 11.4 29 9.9 21 10.1 12 10.4 4 10.5 -5 10.7