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 (2002). Copyright 2005 by the American Geophysical Union.