North Atlantic Oscillation Reconstruction
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               World Data Center for Paleoclimatology
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NOTE: PLEASE CITE ORIGINAL REFERENCES WHEN USING THIS DATA!!!!!
NOTE: This reconstruction is considered obsolete.  See discussion below.

CONTRIBUTORS: Cook, E.R., D'Arrigo, R.D., and Briffa, K.R.
NAME OF DATA SET:  North Atlantic Oscillation Reconstruction

LAST UPDATE:  This reconstruction is considered obsolete.  Newer and
well-verified multi-proxy NAO reconstruction of Cook et al. 2002 
is now available on this server as file nao_cook2002.txt.  Please see
http://www.ngdc.noaa.gov/paleo/pubs/cook2002/cook2002.html
for details and discussion.

IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 1998-037.

SUGGESTED DATA CITATION: Cook, E.R., D'Arrigo, R.D., and Briffa, K.R., 1998, 
North Atlantic Oscillation Reconstruction.  
International Tree-Ring Data Bank.  IGBP PAGES/World Data Center-A for 
Paleoclimatology Data Contribution Series #1998-037.  
NOAA/NGDC Paleoclimatology Program, Boulder CO, USA.

ORIGINAL REFERENCE:
Cook, E.R., D'Arrigo, R.D., and Briffa, K.R., 1998, A reconstruction of the 
North Atlantic Oscillation using tree-ring chronologies from North America 
and Europe, The Holocene 8(1): 9-17. 

ADDITIONAL REFERENCES:
D'Arrigo, R.D., Cook, E.R., Jacoby, G.C., Briffa, K.R. 1994, NAO and sea surface 
temperature signals in tree-ring records from the North Atlantic sector. 
Quaternary Science Reviews 12: 431-440. 

D'Arrigo, R.D., Jacoby, G.C., Cook, E.R. 1992 Impact of recent North Atlantic 
anomalies on surrounding land areas based on dendroclimatic evidence. 
Geophysical Research Letters 19(23): 2321-2324. 

LAST UPDATE:  10/98 (Original receipt by WDC-A Paleo)
GEOGRAPHIC REGION: North Atlantic
PERIOD OF RECORD: 1700 - 1980 AD

LIST OF FILES: NAO.readme.txt (this file), NAO.recon.txt.

DESCRIPTION:
This reconstruction is considered obsolete.  Newer and well-verified 
multi-proxy NAO reconstruction of Cook et al. 2002 is now
available on this server as file nao_cook2002.txt.  Please see
http://www.ngdc.noaa.gov/paleo/pubs/cook2002/cook2002.html
for details and discussion.

Tree-ring records, six from eastern North America and four from northwestern Europe, 
are used to develop the first reconstruction of the winter North Atlantic 
Oscillation (NAO). The reconstructed series spans the interval AD 1701-1980 and 
explains 41% of the variance in the NAO over the AD 1874-1980 calibration period. 
The reconstruction also captures the spectral properties of this index, 
suggesting that the oscillatory character of the NAO is a 
long-term feature of the North Atlantic climate system. 

Low frequency varability (8 years or greater) in the reconstruction is of greater 
reliability than high frequency (i.e. annual) variability, which is potentially 
affected by processing.  See the Original Reference for full discussion of the model.


DATA:

YEARS WINTER NAO RECON                                                                 
1701.   -7.247
1702.    1.720
1703.   -4.385
1704.   -6.729
1705.   -1.802
1706.     .075
1707.    1.683
1708.   -8.337
1709.  -11.144
1710.    3.904
1711.    5.846
1712.    -.046
1713.   -4.667
1714.    3.174
1715.    -.934
1716.    1.156
1717.    2.177
1718.    3.330
1719.    -.787
1720.    1.499
1721.   -1.089
1722.     .604
1723.   -5.575
1724.     .604
1725.    4.744
1726.    3.372
1727.    4.540
1728.   -1.250
1729.   11.480
1730.    7.035
1731.     .440
1732.   -2.378
1733.    1.852
1734.    -.529
1735.    -.428
1736.    7.157
1737.    2.000
1738.    5.309
1739.    5.422
1740.    2.192
1741.   -1.232
1742.    6.259
1743.   -4.510
1744.    4.707
1745.     .690
1746.   -2.362
1747.   -4.963
1748.   -4.280
1749.   -1.085
1750.    6.078
1751.    -.708
1752.    5.944
1753.    6.262
1754.    2.818
1755.   -7.671
1756.    9.083
1757.   -4.787
1758.   -1.316
1759.    5.553
1760.   -3.042
1761.    2.509
1762.   -4.062
1763.   -6.160
1764.    -.572
1765.    5.652
1766.   -1.153
1767.   -5.355
1768.   -6.008
1769.   -2.958
1770.   -5.528
1771.    -.233
1772.   -5.962
1773.    -.752
1774.    2.299
1775.    1.219
1776.    1.486
1777.    8.164
1778.   -1.509
1779.   -2.173
1780.     .426
1781.   -2.085
1782.     .962
1783.    5.672
1784.   -7.409
1785.    4.898
1786.    1.250
1787.     .682
1788.    -.784
1789.   -2.457
1790.   -4.404
1791.    1.167
1792.   -3.573
1793.    4.294
1794.    1.046
1795.    -.871
1796.    5.904
1797.   -3.126
1798.   -1.820
1799.     .983
1800.     .163
1801.    2.886
1802.    4.701
1803.    1.441
1804.    2.657
1805.    2.763
1806.  -12.111
1807.    4.507
1808.    8.749
1809.    4.683
1810.   -5.001
1811.   -6.214
1812.   -7.329
1813.     .027
1814.    2.054
1815.    9.459
1816.    1.669
1817.    7.727
1818.   -5.914
1819.   -4.807
1820.   -4.930
1821.   -2.620
1822.   -3.675
1823.    7.302
1824.   10.952
1825.    1.759
1826.    2.181
1827.    7.659
1828.    3.750
1829.   -5.443
1830.    6.812
1831.     .235
1832.   -1.601
1833.    -.218
1834.    4.053
1835.   -2.906
1836.   -1.479
1837.  -10.903
1838.    3.194
1839.   -8.606
1840.    7.950
1841.   -5.622
1842.    2.270
1843.   -3.899
1844.    2.195
1845.    -.108
1846.   -1.076
1847.   -1.317
1848.   -1.311
1849.    8.004
1850.   -2.810
1851.    6.866
1852.    5.165
1853.    1.318
1854.    4.366
1855.   -3.910
1856.   -3.152
1857.    5.621
1858.     .778
1859.    2.287
1860.    1.813
1861.    1.728
1862.   -7.280
1863.    4.746
1864.   -2.389
1865.    1.826
1866.   -3.240
1867.   -1.832
1868.   -2.057
1869.   -2.847
1870.   -1.844
1871.   -9.199
1872.   -2.577
1873.   -3.716
1874.   -4.948
1875.   -4.805
1876.   -1.584
1877.   -1.832
1878.   -4.705
1879.   -9.343
1880.    -.363
1881.   -8.661
1882.    1.495
1883.   -2.941
1884.    2.820
1885.   -2.430
1886.   -5.700
1887.   -4.670
1888.   -5.775
1889.    5.047
1890.     .611
1891.    -.798
1892.   -8.653
1893.    -.446
1894.    5.008
1895.  -14.114
1896.   -2.806
1897.     .603
1898.   11.764
1899.   -6.963
1900.   -5.036
1901.   -1.063
1902.   -2.294
1903.    1.941
1904.    -.568
1905.     .220
1906.    3.078
1907.    1.553
1908.    4.727
1909.   -1.007
1910.   -3.611
1911.   -8.084
1912.   -3.445
1913.    2.878
1914.   -1.160
1915.    5.755
1916.     .830
1917.   -2.262
1918.   -2.935
1919.    3.707
1920.    2.982
1921.    2.306
1922.     .872
1923.    3.242
1924.     .287
1925.   10.277
1926.  -10.295
1927.    7.521
1928.    4.865
1929.   -2.646
1930.    4.399
1931.    3.360
1932.    2.124
1933.    2.833
1934.    4.785
1935.    6.392
1936.   -8.681
1937.    3.037
1938.    4.796
1939.   -4.531
1940.   -6.139
1941.   -3.545
1942.   -1.015
1943.    1.000
1944.   -2.999
1945.   -1.300
1946.    6.316
1947.   -7.630
1948.    1.025
1949.    4.403
1950.   -2.080
1951.    1.622
1952.     .711
1953.     .164
1954.    5.391
1955.    1.909
1956.   -3.872
1957.    3.516
1958.   -4.223
1959.    4.937
1960.   -9.004
1961.    4.342
1962.   -6.658
1963.  -11.290
1964.   -4.040
1965.   -6.592
1966.   -3.028
1967.    7.063
1968.    2.684
1969.  -10.373
1970.    1.827
1971.    6.948
1972.    7.667
1973.   16.163
1974.    2.780
1975.    2.994
1976.    4.128
1977.   -8.071
1978.   -3.604
1979.    5.966
1980.    4.047