Letter to the editor: Are the North Atlantic Oscillation and the Southern Oscillation related in any time-scale?

Abstract

Abstract. The North Atlantic Oscillation (NAO) and the Southern Oscillation (SO) are compared from the standpoint of a possible common temporal scale of oscillation. To do this a cross-spectrum of the temporal series of NAO and SO indices was determined, ®nding a signi®cant common oscillation of 6±8 years. To assure this ®nding, both series were decomposed in their main oscillations using singular spectrum analysis (SSA). Resulting reconstructed series of 6±8 years' oscillation were then cross-correlated without and with pre-whitened, the latter being signi®cant. The main conclusion is a possible relationship between a common oscillation of 6±8 years that represents about 20% of the SO variance and about 25% of the NAO variance.

Tsallis non-extensive statistical mechanics of El Niño southern oscillation index

“…It was recently found for the southern oscillation index (SOI), characterizing El Niño events [26] that long-range correlations exist between the fluctuations of the index. Also, correlation between the SOI and the North Atlantic Oscillation (NAO) index has been reported [27] having a common oscillation of about 6 − 8 years. The NAO was studied per se, in [28].…”