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

摘要

The North Atlantic Oscillation (NAO) and theSouthern Oscillation (SO) are compared from the standpoint of a possible commontemporal scale of oscillation. To do this a cross-spectrum of the temporalseries of NAO and SO indices was determined, finding a significant commonoscillation of 6-8 years. To assure this finding, both series were decomposed intheir main oscillations using singular spectrum analysis (SSA). Resultingreconstructed series of 6-8 years oscillation were then cross-correlatedwithout and with pre-whitened, the latter being significant. The main conclusionis a possible relationship between a common oscillation of 6-8 years' thatrepresents about 20% of the SO variance and about 25% of the NAO variance.Key words: Meteorology and atmospheric dynamics (climatology;ocean-atmosphere interactions)