cc: Keith Briffa <k.briffa@uea.ac.uk>
date: Fri, 17 Nov 2000 09:15:04 -0500
from: Edward Cook <drdendro@ldeo.columbia.edu>
subject: New NAO recon
to: Phil Jones <p.jones@uea.ac.uk>

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"

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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
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