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Evidence of significant nonrandom behavior in the recurrence of strong El Niño between 1525 and 1988
Author(s) -
Hanson Kirby,
Brier Glenn W.,
Maul George A.
Publication year - 1989
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl016i010p01181
Subject(s) - quasi periodic , monte carlo method , forcing (mathematics) , nonlinear system , periodogram , statistics , mathematics , physics , climatology , geology , astrophysics , quantum mechanics
The precise character of the quasi‐periodic variation in the recurrence of El Niño events has been unclear. To gain insight into the nature of this apparent regularity, a 464‐year record (1525‐1988) of the initiation of "strong" El Niño events, derived from the chronology of Quinn et al. [1987], has been analyzed with a two‐dimensional extension of the periodogram analysis method of Buys Ballot. The method is useful for detecting joint nonlinear interactions between variations at two specified periods. Results indicate joint nonrandom recurrence of strong El Niño events at periods of 6.75 and 14.0 years. From Monte Carlo tests, we estimate the statistical significance of this result to be at the 0.1% level. Alternating ∼95 year‐long time‐blocks, where 6.75‐year and 14.0‐year recurrence periods dominate, is apparent from the analysis. No specific mechanism is offered for the periodic forcing of strong El Niño events, but our observation of significant quasi‐periodic behavior in the initiation of such events at the combined periods of 6.75 and 14.0 years may be a useful clue in efforts to understand and model natural ENSO recurrence.