The NAO index is defined as the standardized (1901-1980) difference between the SLP average of four gridpoints on a 5x5 longitude-latitude grid over the Azores and over Iceland.
The reconstructions are based on a Principal Component Regression Analysis. More details can be found in Luterbacher et al. (2001)
Contact Juerg Luterbacher (firstname.lastname@example.org) for further information, for other reconstructed atmospheric circulation indices and for reprints.
|naomonjurg.dat||60 kilobytes||Monthly 1659-Jul2001|
|naoseajurg.dat||10 kilobytes||Seasonal 1500-1658|