North Atlantic Oscillation Index Coral Sr/Ca 218 Year Reconstruction ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: North Atlantic Oscillation Index Coral Sr/Ca 218 Year Reconstruction LAST UPDATE: 11/2010 (Original receipt by WDC Paleo) CONTRIBUTORS: Goodkin, N.F., K.A. Hughen, S.C. Doney, and W.B. Curry IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2010-123 WDC PALEO CONTRIBUTION SERIES CITATION: Goodkin, N.F., et al. 2010. North Atlantic Oscillation Index Coral Sr/Ca 218 Year Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2010-123. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Goodkin, N.F., K.A. Hughen, S.C. Doney, and W.B. Curry. 2010. Increased multidecadal variability of the North Atlantic Oscillation since 1781. Nature Geoscience, Vol. 1, pp. 844-847, December 2008. Published online: 9 November 2008, doi:10.1038/ngeo352 ABSTRACT: The North Atlantic Oscillation is a meridional oscillation of atmospheric mass measured between Iceland and the Azores, which drives winter climate variability in eastern North America and Europe. A prolonged period of the positive phase during the 1990s led to the suggestion that anthropogenic warming was affecting the behaviour of the North Atlantic Oscillation. However, instrumental records are too short to compare observations during periods of extended warm and cold hemispheric temperatures, and existing palaeoclimate reconstructions primarily capture terrestrial variability. Here we present a record of Sr/Ca, a sea surface temperature proxy, from a Bermuda coral from 1781 to 1999. We use this monthly resolved record to reconstruct past variability of the North Atlantic Oscillation at multiple frequencies. Our record shows enhanced multidecadal scale variability during the late twentieth century compared with the end of the Little Ice Age (1800-1850). We suggest that variability within the North Atlantic Oscillation is linked to the mean temperature of the Northern Hemisphere, which must be considered in any long-term predictions. GEOGRAPHIC REGION: North Atlantic PERIOD OF RECORD: 1781 to 1999 AD FUNDING SOURCES: Woods Hole Oceanographic Institution OCCI Fellowship, US National Science Foundation grant OCE-0402728, Woods Hole Oceanographic Institution grant. DESCRIPTION: North Atlantic Oscillation Index (NAO) reconstruction based on winter coral strontium-to-calcium ratio, a proxy for winter SST. The SST-based, multifrequency reconstruction of the NAO extends back to the end of the Little Ice Age (LIA). It is the first non-terrestrial reconstruction showing long-term multidecadal behaviour of the NAO. Coral Sr/Ca was used to reconstruct the NAO by filtering the Sr/Ca record to isolate the two frequency bands where the coral data are coherent with the NAO. To evaluate this approach, the same process was applied to instrumental SST and NAO data. The 3-5 year coherence is 0.40 (95% significant, n effective = 124) and the 20-100 year coherence is -0.47 (95% significant, n effective = 24), both with the expected phase relationship. These results agree well with those found for the Sr/Ca and instrumental NAO. DATA: Inter-annual (3-5 year), multidecadal (20-100 year), and combined Coral Sr/Ca NAO reconstructions. Fig.3aCombinedIndex Fig.3b 3-5yrIndex Fig.3d 20-100yr Index YearAD YearAD YearAD 1997 -0.0181 1996 -0.0002 1995 -0.0023 1994 0.0041 1993 -0.0032 1992 -0.0115 1991 0.0024 1990 0.0154 1989 -0.0070 1988 -0.0174 1988 -0.0159 1988 0.0015 1987 0.0082 1987 0.0099 1987 0.0017 1986 0.0069 1986 0.0068 1986 -0.0001 1985 -0.0047 1985 -0.0075 1985 -0.0028 1984 0.0096 1984 0.0039 1984 -0.0057 1983 0.0175 1983 0.0088 1983 -0.0087 1982 0.0024 1982 -0.0094 1982 -0.0118 1981 -0.0025 1981 -0.0172 1981 -0.0147 1980 0.0161 1980 -0.0014 1980 -0.0175 1979 0.02 1979 0.0002 1979 -0.0198 1978 0.0178 1978 -0.0033 1978 -0.0211 1977 0.0243 1977 0.0025 1977 -0.0218 1976 0.0268 1976 0.0058 1976 -0.021 1975 0.0302 1975 0.0112 1975 -0.019 1974 0.009 1974 -0.0068 1974 -0.0158 1973 -0.0016 1973 -0.0131 1973 -0.0115 1972 0.0156 1972 0.0094 1972 -0.0062 1971 -0.0098 1971 -0.0098 1971 0 1970 -0.0197 1970 -0.0129 1970 0.0068 1969 0.0037 1969 0.0175 1969 0.0138 1968 -0.0332 1968 -0.0120 1968 0.0212 1967 -0.0373 1967 -0.0088 1967 0.0285 1966 -0.0093 1966 0.0261 1966 0.0354 1965 -0.0463 1965 -0.0053 1965 0.041 1964 -0.0619 1964 -0.0164 1964 0.0455 1963 -0.0463 1963 0.0023 1963 0.0486 1962 -0.034 1962 0.0160 1962 0.05 1961 -0.043 1961 0.0071 1961 0.0501 1960 -0.0773 1960 -0.0285 1960 0.0488 1959 -0.051 1959 -0.0050 1959 0.046 1958 -0.0081 1958 0.0340 1958 0.0421 1957 -0.0437 1957 -0.0067 1957 0.037 1956 -0.066 1956 -0.0350 1956 0.031 1955 -0.0261 1955 -0.0016 1955 0.0245 1954 0.006 1954 0.0236 1954 0.0176 1953 -0.0004 1953 0.0100 1953 0.0104 1952 -0.0099 1952 -0.0065 1952 0.0034 1951 0.0024 1951 -0.0004 1951 -0.0028 1950 0.0044 1950 -0.0038 1950 -0.0082 1949 0.0022 1949 -0.0104 1949 -0.0126 1948 0.0082 1948 -0.0079 1948 -0.0161 1947 0.0194 1947 0.0018 1947 -0.0176 1946 0.0247 1946 0.0075 1946 -0.0172 1945 0.01 1945 -0.0052 1945 -0.0152 1944 0.0025 1944 -0.0090 1944 -0.0115 1943 0.0067 1943 0.0004 1943 -0.0063 1942 0.0091 1942 0.0087 1942 -0.0004 1941 -0.0028 1941 0.0027 1941 0.0055 1940 -0.0253 1940 -0.0147 1940 0.0106 1939 -0.0221 1939 -0.0073 1939 0.0148 1938 0.0015 1938 0.0191 1938 0.0176 1937 -0.0121 1937 0.0071 1937 0.0192 1936 -0.0353 1936 -0.0157 1936 0.0196 1935 -0.0179 1935 0.0013 1935 0.0192 1934 -0.0139 1934 0.0040 1934 0.0179 1933 -0.0242 1933 -0.0082 1933 0.016 1932 -0.0148 1932 -0.0011 1932 0.0137 1931 -0.0095 1931 0.0019 1931 0.0114 1930 -0.0108 1930 -0.0015 1930 0.0093 1929 -0.0114 1929 -0.0039 1929 0.0075 1928 -0.0033 1928 0.0024 1928 0.0057 1927 -0.0012 1927 0.0025 1927 0.0037 1926 -0.0058 1926 -0.0044 1926 0.0014 1925 0.0039 1925 0.0024 1925 -0.0015 1924 -0.0027 1924 -0.0076 1924 -0.0049 1923 -0.0013 1923 -0.0100 1923 -0.0087 1922 0.0235 1922 0.0106 1922 -0.0129 1921 0.0245 1921 0.0076 1921 -0.0169 1920 0.025 1920 0.0045 1920 -0.0205 1919 0.0241 1919 0.0007 1919 -0.0234 1918 0.0041 1918 -0.0216 1918 -0.0257 1917 0.0179 1917 -0.0094 1917 -0.0273 1916 0.0363 1916 0.0081 1916 -0.0282 1915 0.0317 1915 0.0031 1915 -0.0286 1914 0.0285 1914 -0.0001 1914 -0.0286 1913 0.0211 1913 -0.0069 1913 -0.028 1912 0.0275 1912 0.0010 1912 -0.0265 1911 0.0299 1911 0.0056 1911 -0.0243 1910 0.02 1910 -0.0017 1910 -0.0217 1909 0.0221 1909 0.0030 1909 -0.0191 1908 0.0129 1908 -0.0039 1908 -0.0168 1907 0.0073 1907 -0.0072 1907 -0.0145 1906 0.013 1906 0.0005 1906 -0.0125 1905 -0.0016 1905 -0.0123 1905 -0.0107 1904 0.0038 1904 -0.0054 1904 -0.0092 1903 0.0328 1903 0.0247 1903 -0.0081 1902 0.0203 1902 0.0131 1902 -0.0072 1901 -0.0193 1901 -0.0250 1901 -0.0057 1900 -0.012 1900 -0.0154 1900 -0.0034 1899 0.0075 1899 0.0075 1899 0 1898 0.0164 1898 0.0206 1898 0.0042 1897 -0.0032 1897 0.0062 1897 0.0094 1896 -0.0426 1896 -0.0275 1896 0.0151 1895 -0.028 1895 -0.0073 1895 0.0207 1894 -0.0304 1894 -0.0044 1894 0.026 1893 -0.0414 1893 -0.0111 1893 0.0303 1892 -0.0172 1892 0.0162 1892 0.0334 1891 -0.0176 1891 0.0168 1891 0.0344 1890 -0.0326 1890 0.0007 1890 0.0333 1889 -0.0365 1889 -0.0066 1889 0.0299 1888 -0.0182 1888 0.0071 1888 0.0253 1887 -0.0163 1887 0.0035 1887 0.0198 1886 -0.0304 1886 -0.0168 1886 0.0136 1885 -0.0098 1885 -0.0025 1885 0.0073 1884 0.0031 1884 0.0049 1884 0.0018 1883 -0.005 1883 -0.0071 1883 -0.0021 1882 -0.0062 1882 -0.0099 1882 -0.0037 1881 -0.0004 1881 -0.0029 1881 -0.0025 1880 -0.0022 1880 -0.0012 1880 0.001 1879 0.0026 1879 0.0085 1879 0.0059 1878 -0.0008 1878 0.0103 1878 0.0111 1877 -0.0236 1877 -0.0077 1877 0.0159 1876 -0.0272 1876 -0.0073 1876 0.0199 1875 -0.0313 1875 -0.0086 1875 0.0227 1874 -0.0233 1874 0.0010 1874 0.0243 1873 -0.0062 1873 0.0183 1873 0.0245 1872 -0.0216 1872 0.0019 1872 0.0235 1871 -0.0225 1871 -0.0009 1871 0.0216 1870 -0.0232 1870 -0.0042 1870 0.019 1869 -0.0369 1869 -0.0206 1869 0.0163 1868 -0.0154 1868 -0.0019 1868 0.0135 1867 -0.0074 1867 0.0033 1867 0.0107 1866 -0.0035 1866 0.0044 1866 0.0079 1865 0.0139 1865 0.0185 1865 0.0046 1864 -0.0122 1864 -0.0112 1864 0.001 1863 -0.0164 1863 -0.0192 1863 -0.0028 1862 0.0171 1862 0.0106 1862 -0.0065 1861 0.0132 1861 0.0032 1861 -0.01 1860 0.0121 1860 -0.0015 1860 -0.0136 1859 0.0105 1859 -0.0067 1859 -0.0172 1858 0.0199 1858 -0.0007 1858 -0.0206 1857 0.0486 1857 0.0251 1857 -0.0235 1856 0.0042 1856 -0.0215 1856 -0.0257 1855 -0.0041 1855 -0.0312 1855 -0.0271 1854 0.0416 1854 0.0136 1854 -0.028 1853 0.0392 1853 0.0109 1853 -0.0283 1852 0.0364 1852 0.0082 1852 -0.0282 1851 0.0241 1851 -0.0034 1851 -0.0275 1850 0.0157 1850 -0.0106 1850 -0.0263 1849 0.024 1849 -0.0011 1849 -0.0251 1848 0.0304 1848 0.0068 1848 -0.0236 1847 0.0178 1847 -0.0039 1847 -0.0217 1846 0.0125 1846 -0.0070 1846 -0.0195 1845 0.0127 1845 -0.0048 1845 -0.0175 1844 0.01 1844 -0.0059 1844 -0.0159 1843 0.0324 1843 0.0180 1843 -0.0144 1842 0.0197 1842 0.0068 1842 -0.0129 1841 -0.0042 1841 -0.0159 1841 -0.0117 1840 -0.0054 1840 -0.0162 1840 -0.0108 1839 0.0116 1839 0.0014 1839 -0.0102 1838 0.0322 1838 0.0221 1838 -0.0101 1837 0.0223 1837 0.0118 1837 -0.0105 1836 -0.0037 1836 -0.0150 1836 -0.0113 1835 -0.0114 1835 -0.0237 1835 -0.0123 1834 0.0222 1834 0.0088 1834 -0.0134 1833 0.0232 1833 0.0089 1833 -0.0143 1832 -0.0058 1832 -0.0207 1832 -0.0149 1831 0.0269 1831 0.0121 1831 -0.0148 1830 0.0322 1830 0.0176 1830 -0.0146 1829 -0.0047 1829 -0.0192 1829 -0.0145 1828 0.0125 1828 -0.0018 1828 -0.0143 1827 0.0175 1827 0.0036 1827 -0.0139 1826 0.0004 1826 -0.0128 1826 -0.0132 1825 0.0185 1825 0.0060 1825 -0.0125 1824 0.0208 1824 0.0090 1824 -0.0118 1823 0.003 1823 -0.0079 1823 -0.0109 1822 0.0057 1822 -0.0038 1822 -0.0095 1821 0.0115 1821 0.0034 1821 -0.0081 1820 0.0059 1820 -0.0006 1820 -0.0065 1819 -0.0092 1819 -0.0139 1819 -0.0047 1818 0.0019 1818 -0.0015 1818 -0.0034 1817 0.0153 1817 0.0127 1817 -0.0026 1816 0.002 1816 -0.0005 1816 -0.0025 1815 0.0026 1815 -0.0004 1815 -0.003 1814 0.0033 1814 -0.0003 1814 -0.0036 1813 0.0014 1813 -0.0029 1813 -0.0043 1812 -0.0017 1812 -0.0067 1812 -0.005 1811 0.0019 1811 -0.0036 1811 -0.0055 1810 0.0202 1810 0.0147 1810 -0.0055 1809 0.0023 1809 -0.0027 1809 -0.005 1808 -0.0102 1808 -0.0140 1808 -0.0038 1807 -0.0012 1807 -0.0035 1807 -0.0023 1806 -0.0052 1806 -0.0057 1806 -0.0005 1805 0.0078 1805 0.0089 1805 0.0011 1804 0.0018 1804 0.0042 1804 0.0024 1803 -0.0094 1803 -0.0061 1803 0.0033 1802 -0.0015 1802 0.0023 1802 0.0038 1801 -0.0045 1801 -0.0006 1801 0.0039 1800 0.0024 1800 0.0059 1800 0.0035 1799 -0.0009 1799 0.0018 1799 0.0027 1798 -0.0108 1798 -0.0092 1798 0.0016 1797 -0.0085 1797 -0.0080 1797 0.0005 1796 -0.0053 1796 -0.0053 1796 0 1795 0.003 1795 0.0029 1795 -0.0001 1794 -0.0014 1794 -0.0007 1794 0.0007 1793 0.0039 1793 0.0050 1793 0.0011 1792 0.0095 1791 -0.0098 1790 -0.0151 1789 0.0042 1788 0.0180 1787 0.0012 1786 -0.0100 1785 0.0001 1784 -0.0092