Evolution of the ENSO signal over the tropical Pacific‐Atlantic domain

Abstract

Space‐time evolution of the dominant El Niño–Southern Oscillation (ENSO) signal in the tropical eastern Pacific‐Atlantic domain is investigated (1979–2004). Multi‐Taper‐Method, Singular Value Decomposition (MTM/SVD) and complex empirical orthogonal functions (CEOF) are applied to four variables: sea surface temperature (SST), upper ocean heat storage (HST), zonal surface wind (ZSW), and sea level pressure (SLP). Anomalous evolution for all variables find a dominant ENSO signal (3.4–5.7 years band period) composed of mixed standing modes and propagating modes. The latter evolve eastward from the eastern Pacific Ocean, into the tropical Atlantic basin at ∼20 cm s−1. As such, peak signals in the equatorial Atlantic lag that in the eastern equatorial Pacific by ∼12–18 months. The slow SST/SLP coupled wave propagating through the Caribbean Sea resembles the global ENSO wave identified by White and Cayan (2000).