Is the North Atlantic Oscillation a random walk?

The North Atlantic Oscillation is a major mode of large-scale climate variability which contains a broad spectrum of variations. There are substantial contributions from short term 2-5 year variations, which have clearly marked teleconnections. Decadal trends are also apparent in the historical hist...

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Bibliographic Details
Main Authors: David B. Stephenson, Valentina Pavan, Roxana Bojariu
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2000
Subjects:
NAO
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.54.1007
http://www-sv.cict.fr/lsp/Stephen/ABS/ijc98.ps.gz
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Summary:The North Atlantic Oscillation is a major mode of large-scale climate variability which contains a broad spectrum of variations. There are substantial contributions from short term 2-5 year variations, which have clearly marked teleconnections. Decadal trends are also apparent in the historical historical record of the North Atlantic Oscillation and may be due to either stochastic or deterministic processes. Evidence is presented that suggests the NAO exhibits "long-range" dependence having winter values residually correlated over many years. Several simple stochastic models have been used to fit the NAO SLP wintertime index over the period 1864-1998, and their performance at predicting the following year has been assessed. Long-range fractionally integrated noise provides a better fit than does either stationary red noise or a non-stationary random walk. Key words: North Atlantic Oscillation, NAO, variability, stochastic processes, stationarity, trends, long-range dependence, forecast.