Mechanism of the Zonal Displacements of the Pacific Warm Pool: Implications for ENSO

• Published in: Science (American Association for the Advancement of Science) Vol. 274; no. 5292; pp. 1486 - 1489
• Main Authors: Picaut, J., Ioualalen, M., Menkes, C., Delcroix, T., McPhaden, M. J.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 29.11.1996; American Association for the Advancement of Science; The American Association for the Advancement of Science; American Association for the Advancement of Science (AAAS)
• Subjects: Advection; Atmospherics; Buoys; Earth Sciences; Earth, ocean, space; El Nino; El Niño; Environmental Sciences; Exact sciences and technology; External geophysics; Geophysics; Global Changes; Marine; Migration; Ocean currents; Ocean-atmosphere interaction; Oceanography; Oceans; Pacific Ocean; Physics; Physics of the oceans; Salinity; Saltwater; Sciences of the Universe; Sea-air exchange processes; Southern Oscillation; Surface water; Temperature; Trajectories; Water; Pacific Ocean; Tropical Pacific Ocean; IS, Equatorial Pacific; Tropical Pacific; ISEW, Western Equatorial Pacific; Advection; El Nino; Sea current; Southern oscillation; Surface water; Ocean atmosphere interaction; Ocean model
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.274.5292.1486

The western equatorial Pacific warm pool is subject to strong east-west migrations on interannual time scales in phase with the Southern Oscillation Index. The dominance of surface zonal advection in this migration is demonstrated with four different current data sets and three ocean models. The eastward advection of warm and less saline water from the western Pacific together with the westward advection of cold and more saline water from the central-eastern Pacific induces a convergence of water masses at the eastern edge of the warm pool and a well-defined salinity front. The location of this convergence is zonally displaced in association with EI Niño-La Niña wind-driven surface current variations. These advective processes and water-mass convergences have significant implications for understanding and simulating coupled ocean-atmosphere interactions associated with EI Niño-Southern Oscillation (ENSO).