cc: Keith Briffa date: Fri, 17 Nov 2000 09:15:04 -0500 from: Edward Cook subject: New NAO recon to: Phil Jones Hi Phil, Here is the new DJFM NAO recon. It is in two forms. The LINK NAO2 recon is based on extending the recon by stepping back in 25 year increments from 1750 and dropping out the shorter proxy records in the process. Then each 25 year extension is added to the beginning of the reconstruction (e.g. 1725-1749 is linked with 1750-1979, 1700-1724 is linked with 1725-1979, ...), with its variance adjusted to link in homogenously. This process is illustrated in the attached PDF plot REC/RSQ.1826_PLT_PDF. The MEAN NAO2 recon is the average of all the recons using their entire periods (e.g. 1750-1979, 1725-1979, 1700-1979, ...) with their variances adjusted accordingly. These two recons are ploted in REC1/REC2_1826.PLT_PDF for comparison. Kalman filter comparisons of these recons with both your extended SLP-only 1781-1995 NAO index and Luterbacher's mixed instrumental index back to 1659 (plot KALMAN.JONES/LUT_1826_PLT_PDF) indicate that the MEAN NAO2 is slightly better. I also compared Luterbacher's DJF NAO recon with MEAN NAO2 over the period 1500-1658 and got generally good results (significant agreement from 1500-1580 anyway). Finally, SITE.MAP_SITES_PDF and SITE.MAP_BETAS_PDF show the locations of the proxies used and the most important regression betas, respectively. Cheers, Ed YEAR LINK NAO2 MEAN NAO2 1400 -0.119 -0.119 1401 -1.027 -1.027 1402 -0.430 -0.430 1403 -0.209 -0.209 1404 -0.373 -0.373 1405 0.184 0.184 1406 0.455 0.455 1407 -0.058 -0.058 1408 -0.200 -0.200 1409 -0.088 -0.088 1410 -1.035 -1.035 1411 -0.277 -0.277 1412 -0.814 -0.814 1413 0.663 0.663 1414 -0.343 -0.343 1415 -0.130 -0.130 1416 -0.978 -0.978 1417 0.076 0.076 1418 -0.129 -0.129 1419 -0.410 -0.410 1420 0.287 0.287 1421 -0.068 -0.068 1422 0.560 0.560 1423 -0.196 -0.196 1424 -0.037 -0.037 1425 -0.191 -0.191 1426 0.840 0.840 1427 -0.674 -0.674 1428 0.279 0.279 1429 0.256 0.256 1430 -0.476 -0.476 1431 -0.697 -0.697 1432 0.295 0.295 1433 -0.628 -0.628 1434 0.242 0.242 1435 -0.367 -0.367 1436 0.059 0.059 1437 -0.311 -0.311 1438 -0.004 -0.004 1439 -1.020 -1.020 1440 -0.420 -0.420 1441 -1.321 -1.321 1442 -0.144 -0.144 1443 0.638 0.638 1444 -0.241 -0.241 1445 0.522 0.522 1446 -0.286 -0.286 1447 -0.808 -0.808 1448 -1.045 -1.045 1449 0.184 0.184 1450 -1.035 -1.112 1451 -0.613 -0.600 1452 -0.494 -0.551 1453 0.080 -0.064 1454 -0.078 -0.028 1455 0.540 0.525 1456 0.756 0.849 1457 0.346 0.243 1458 -0.790 -0.839 1459 -0.017 -0.143 1460 0.082 0.138 1461 -0.616 -0.571 1462 -0.569 -0.604 1463 -0.975 -0.970 1464 -0.013 -0.096 1465 0.921 0.894 1466 -0.036 0.091 1467 -0.786 -0.487 1468 -0.280 -0.077 1469 -0.078 0.052 1470 -0.659 -0.533 1471 0.363 0.259 1472 -0.204 -0.397 1473 -0.161 -0.275 1474 0.180 0.215 1475 -1.599 -1.090 1476 -0.805 -0.772 1477 0.251 0.159 1478 0.940 1.162 1479 1.391 1.133 1480 -0.312 -0.222 1481 -0.524 -0.248 1482 0.320 0.019 1483 -0.150 -0.135 1484 0.188 -0.069 1485 0.356 0.666 1486 0.093 0.114 1487 -0.117 -0.239 1488 -0.466 -0.390 1489 -0.197 -0.265 1490 -0.644 -0.658 1491 -0.389 -0.337 1492 -1.082 -0.941 1493 1.339 1.408 1494 -0.135 -0.190 1495 -1.092 -0.979 1496 0.033 0.099 1497 0.715 0.952 1498 0.969 0.417 1499 -1.186 -1.024 1500 0.921 1.057 1501 -0.232 -0.453 1502 -0.506 -0.461 1503 -1.170 -1.562 1504 -0.169 -0.439 1505 -0.800 -0.748 1506 -0.301 -0.071 1507 0.062 0.233 1508 0.779 1.069 1509 1.258 1.578 1510 0.740 0.809 1511 -1.015 -0.812 1512 -0.373 -0.321 1513 -0.611 -0.842 1514 -0.676 -0.518 1515 0.839 1.390 1516 -0.051 -0.107 1517 0.402 0.485 1518 0.536 -0.005 1519 -0.567 -0.152 1520 0.279 0.443 1521 1.289 1.487 1522 -0.271 -0.261 1523 0.635 0.621 1524 -0.345 -0.273 1525 0.090 0.166 1526 0.719 1.056 1527 -0.134 0.112 1528 -0.270 0.211 1529 0.582 0.857 1530 0.054 -0.123 1531 -0.405 -0.197 1532 -0.901 -0.993 1533 -0.524 -0.330 1534 -0.020 -0.494 1535 -0.397 -0.174 1536 0.682 0.432 1537 -0.085 -0.148 1538 0.596 0.441 1539 -0.624 -0.467 1540 -0.282 0.184 1541 0.093 0.072 1542 0.245 0.396 1543 -0.015 -0.539 1544 -0.960 -0.888 1545 1.061 0.925 1546 -0.341 -0.493 1547 0.134 -0.009 1548 0.579 0.862 1549 -0.479 -0.261 1550 -0.521 -0.759 1551 -0.621 -0.534 1552 -0.112 -0.287 1553 0.126 0.362 1554 -0.473 -0.500 1555 0.197 0.134 1556 0.313 0.251 1557 0.072 0.198 1558 -0.053 -0.146 1559 -1.409 -1.412 1560 0.471 0.466 1561 0.035 0.078 1562 -0.438 -0.098 1563 -0.599 -0.433 1564 -0.840 -0.763 1565 -0.199 -0.298 1566 -0.551 -0.358 1567 -0.206 -0.470 1568 -0.588 -0.297 1569 0.290 0.009 1570 -0.082 -0.293 1571 -0.987 -0.684 1572 0.117 -0.048 1573 -0.961 -0.963 1574 0.379 0.254 1575 1.229 0.768 1576 0.387 0.439 1577 0.955 1.180 1578 1.027 1.316 1579 0.418 0.490 1580 -0.334 -0.733 1581 -0.485 -0.495 1582 0.908 0.443 1583 -0.161 -0.147 1584 -0.859 -0.659 1585 0.452 0.429 1586 -0.073 -0.235 1587 -1.090 -0.759 1588 0.942 0.963 1589 0.124 0.346 1590 -0.089 -0.317 1591 -0.423 -0.418 1592 -0.093 0.140 1593 -0.101 0.008 1594 -0.409 -0.401 1595 0.280 0.339 1596 0.279 0.151 1597 -0.881 -0.791 1598 -0.388 -0.678 1599 -0.298 -0.432 1600 0.449 0.550 1601 -0.547 -0.168 1602 -0.200 -0.073 1603 0.773 0.639 1604 -0.487 -0.538 1605 0.588 0.537 1606 0.812 0.698 1607 -0.027 0.301 1608 0.454 0.254 1609 -0.451 -0.436 1610 -0.218 -0.444 1611 0.607 0.799 1612 -1.269 -1.419 1613 1.591 1.702 1614 -0.357 -0.147 1615 -0.274 -0.211 1616 0.567 0.642 1617 0.440 0.835 1618 -0.554 -0.728 1619 -0.324 -0.455 1620 -0.491 -0.518 1621 0.039 -0.051 1622 0.096 0.014 1623 0.394 0.403 1624 -0.278 -0.021 1625 -0.772 -0.694 1626 0.500 0.524 1627 0.457 0.209 1628 -0.182 -0.775 1629 -0.120 -0.045 1630 0.665 0.176 1631 0.082 0.627 1632 1.114 0.311 1633 -0.427 -0.097 1634 0.740 0.292 1635 -0.600 -0.369 1636 0.563 0.286 1637 0.831 0.557 1638 -0.364 -0.850 1639 0.046 0.124 1640 0.283 0.206 1641 -1.245 -0.838 1642 -0.298 -0.296 1643 0.178 -0.181 1644 -0.015 0.304 1645 -0.245 -0.215 1646 -1.077 -0.860 1647 0.054 0.382 1648 -0.553 0.047 1649 -0.067 0.321 1650 -0.442 -0.843 1651 0.260 -0.129 1652 0.289 -0.139 1653 0.137 -0.002 1654 -0.017 -0.672 1655 -0.941 -0.601 1656 0.181 -0.315 1657 -0.207 -0.350 1658 -0.158 -0.108 1659 -0.597 -0.819 1660 0.267 0.487 1661 -0.271 0.960 1662 -0.027 0.112 1663 -1.023 -1.287 1664 0.182 0.046 1665 -0.181 0.034 1666 -0.940 -0.431 1667 -0.582 -0.477 1668 -0.905 -0.123 1669 -0.634 -0.612 1670 -0.199 -0.380 1671 0.261 0.065 1672 0.109 -0.083 1673 0.258 -0.014 1674 0.575 0.782 1675 -1.242 -0.986 1676 -0.089 -0.080 1677 -0.346 -0.067 1678 0.418 0.464 1679 -0.613 -0.538 1680 -0.121 0.856 1681 -0.296 -1.385 1682 -0.436 -0.447 1683 0.445 1.344 1684 -1.302 -1.749 1685 -0.411 0.249 1686 0.028 -0.296 1687 -0.448 0.123 1688 -0.783 -0.797 1689 0.609 0.104 1690 -0.024 0.506 1691 0.099 -0.358 1692 -0.889 -1.001 1693 1.216 1.059 1694 1.224 0.640 1695 -0.896 -0.530 1696 -1.054 -0.765 1697 -0.702 -1.013 1698 -0.859 -0.484 1699 -0.519 -0.525 1700 -0.317 -0.009 1701 0.040 0.065 1702 0.602 0.042 1703 0.528 0.504 1704 -0.649 -0.292 1705 0.206 -0.109 1706 -0.074 -0.109 1707 -0.523 0.041 1708 -1.405 -1.252 1709 -0.502 -0.102 1710 0.531 0.341 1711 0.433 0.275 1712 0.399 0.445 1713 -0.112 0.496 1714 0.148 0.617 1715 0.461 0.409 1716 0.129 0.457 1717 -0.068 0.238 1718 0.329 0.387 1719 -0.031 -0.080 1720 -0.240 0.062 1721 -0.321 -0.449 1722 0.118 0.217 1723 -0.304 -0.126 1724 -0.397 -0.120 1725 0.803 0.440 1726 -0.075 -0.400 1727 -0.162 -0.052 1728 -0.265 -0.375 1729 0.058 0.079 1730 0.208 -0.292 1731 -0.343 -0.370 1732 0.033 0.012 1733 -0.099 0.515 1734 0.392 0.468 1735 -0.946 -0.848 1736 -0.633 -0.180 1737 -0.270 -0.149 1738 0.854 1.145 1739 0.335 0.169 1740 0.229 0.143 1741 -0.773 -0.170 1742 0.088 0.133 1743 -0.072 -0.157 1744 0.970 1.433 1745 -0.108 -0.317 1746 -0.650 -0.625 1747 -0.581 -0.296 1748 -0.797 -0.840 1749 0.266 0.118 1750 0.536 0.491 1751 -0.090 -0.595 1752 -0.431 -0.712 1753 0.804 1.134 1754 -0.804 -0.722 1755 -0.351 -0.337 1756 0.002 -0.248 1757 -0.338 -0.808 1758 -0.841 -0.295 1759 0.590 0.399 1760 -0.442 -0.731 1761 -0.175 -0.190 1762 0.331 -0.159 1763 -0.737 -0.738 1764 0.311 0.243 1765 -0.011 -0.169 1766 -1.012 -0.812 1767 -0.674 -0.850 1768 -0.990 -0.848 1769 0.244 0.041 1770 -0.084 0.102 1771 -0.182 -0.315 1772 -0.970 -0.941 1773 0.477 0.391 1774 -0.110 -0.247 1775 0.585 0.471 1776 0.299 0.570 1777 0.525 0.365 1778 -0.547 -0.660 1779 0.346 0.788 1780 -1.447 -0.907 1781 0.261 0.568 1782 0.013 0.277 1783 0.462 0.454 1784 -1.414 -1.593 1785 0.051 -0.185 1786 -0.414 -0.378 1787 -0.198 -0.129 1788 -0.477 -0.981 1789 -0.242 -0.134 1790 -0.401 0.327 1791 -0.189 0.016 1792 -0.441 -0.157 1793 0.505 0.646 1794 -0.169 0.204 1795 -0.037 0.082 1796 0.766 0.675 1797 -0.240 0.033 1798 -0.140 -0.161 1799 0.144 -0.020 1800 -1.005 -0.986 1801 0.812 1.024 1802 0.478 0.445 1803 -0.295 -0.654 1804 -0.156 -0.054 1805 -0.043 -0.097 1806 -0.761 -0.233 1807 0.171 0.064 1808 -0.078 -0.269 1809 0.209 0.167 1810 -0.424 -0.778 1811 0.151 0.265 1812 -1.051 -0.963 1813 -0.174 0.256 1814 -0.264 -0.477 1815 1.241 0.936 1816 -0.303 -0.204 1817 0.815 1.012 1818 -0.741 -0.670 1819 -0.598 -0.258 1820 -0.147 0.359 1821 -0.255 -0.203 1822 0.308 0.034 1823 0.277 0.253 1824 0.070 0.347 1825 0.201 0.065 1826 -0.063 0.040 1827 -0.922 -0.978 1828 0.789 0.679 1829 -1.422 -1.285 1830 0.199 -0.103 1831 -0.452 -0.364 1832 -0.117 -0.311 1833 -0.663 -0.524 1834 0.683 0.541 1835 -0.405 -0.683 1836 -0.356 0.168 1837 -1.890 -1.591 1838 -0.106 -0.334 1839 -0.577 -0.211 1840 0.023 0.125 1841 -0.346 -0.276 1842 -0.411 -0.225 1843 0.484 0.309 1844 0.407 0.311 1845 -0.325 -0.460 1846 0.130 -0.085 1847 -0.637 -0.536 1848 0.035 0.106 1849 -0.217 -0.080 1850 -0.139 0.190 1851 -0.308 -0.318 1852 -0.049 0.165 1853 -1.000 -0.809 1854 0.456 0.535 1855 -1.153 -1.053 1856 -0.216 -0.335 1857 -0.283 -0.431 1858 0.557 1.024 1859 0.117 -0.059 1860 -0.204 -0.541 1861 0.268 0.217 1862 -0.464 0.176 1863 -0.234 -0.064 1864 0.165 -0.073 1865 -0.173 -0.075 1866 0.707 0.801 1867 -0.090 0.048 1868 0.249 0.346 1869 0.260 0.069 1870 -0.990 -0.719 1871 -0.885 -0.910 1872 -0.310 -0.447 1873 -0.774 -0.550 1874 0.386 0.383 1875 -0.518 -0.396 1876 -0.559 -0.373 1877 -0.466 0.147 1878 0.552 0.607 1879 -1.291 -1.173 1880 0.477 0.401 1881 -0.351 -0.499 1882 1.346 1.301 1883 0.129 0.233 1884 0.177 0.175 1885 0.036 -0.296 1886 -0.318 -0.350 1887 -0.356 0.012 1888 -0.177 -0.200 1889 0.197 -0.093 1890 -0.156 0.024 1891 0.036 0.300 1892 -0.378 -0.010 1893 -0.256 -0.662 1894 0.005 0.189 1895 -0.919 -0.917 1896 -0.358 -0.240 1897 -0.017 0.170 1898 0.552 0.609 1899 -0.895 -0.469 1900 -1.526 -1.283 1901 -0.945 -0.610 1902 -0.178 -0.294 1903 1.697 1.597 1904 -0.828 -0.608 1905 0.807 0.816 1906 0.624 0.309 1907 0.686 0.285 1908 0.117 0.656 1909 -0.320 -0.086 1910 -0.245 0.121 1911 -0.498 -0.945 1912 -0.436 -0.545 1913 0.442 0.267 1914 0.190 -0.169 1915 -0.263 -0.217 1916 0.210 0.279 1917 -1.498 -1.551 1918 0.139 0.186 1919 0.102 -0.054 1920 1.544 0.858 1921 0.300 -0.526 1922 -0.240 -0.003 1923 1.227 0.929 1924 -1.107 -0.550 1925 0.610 0.624 1926 -0.255 -0.361 1927 0.465 0.492 1928 0.076 -0.301 1929 -0.697 -0.894 1930 0.319 0.065 1931 -1.096 -0.672 1932 -0.200 0.103 1933 0.664 0.446 1934 0.068 0.486 1935 -0.001 0.176 1936 -1.444 -1.496 1937 0.792 0.831 1938 0.459 0.519 1939 -0.433 -0.200 1940 -0.863 -1.241 1941 -0.480 -0.604 1942 -0.938 -0.909 1943 0.543 0.260 1944 -0.667 -0.667 1945 1.462 1.675 1946 0.721 0.318 1947 -2.123 -1.884 1948 0.573 0.767 1949 0.241 -0.070 1950 0.305 0.821 1951 -0.229 0.044 1952 -0.535 -0.783 1953 -0.155 0.063 1954 -0.136 -0.210 1955 -1.450 -1.258 1956 -0.586 -0.616 1957 1.708 1.854 1958 -1.435 -1.298 1959 -0.249 -0.714 1960 -1.141 -0.867 1961 1.107 0.932 1962 -0.931 -0.913 1963 -1.882 -1.583 1964 -0.231 -0.459 1965 -0.895 -0.407 1966 0.211 0.280 1967 1.011 0.806 1968 -0.148 -0.019 1969 -1.538 -1.503 1970 -0.051 0.062 1971 -0.012 -0.173 1972 -0.337 0.131 1973 1.619 1.267 1974 0.673 0.805 1975 0.283 0.283 1976 0.237 0.237 1977 -0.307 -0.307 1978 -0.699 -0.699 1979 -1.419 -1.419 Attachment Converted: "c:\eudora\attach\SITE.MAP_SITES_PDF.pdf" Attachment Converted: "c:\eudora\attach\SITE.MAP_BETAS_PDF.pdf" Attachment Converted: "c:\eudora\attach\REC=RSQ.1826_PLT_PDF.pdf" Attachment Converted: "c:\eudora\attach\KALMAN.JONES=LUT_1826_PLT_PDF.p" Attachment Converted: "c:\eudora\attach\REC1=REC2_1826.PLT_PDF.pdf" Attachment Converted: "c:\eudora\attach\KALMAN.REC2_1826_1500_PLT_PDF.p" ================================== Dr. Edward R. Cook Doherty Senior Scholar Tree-Ring Laboratory Lamont-Doherty Earth Observatory Palisades, New York 10964 USA Phone: 1-845-365-8618 Fax: 1-845-365-8152 Email: drdendro@ldeo.columbia.edu ==================================