GEOSAT sea level anomalies in the Western equatorial Pacific during the 1986-87 El Nino, elucidated as equatorial Kelvin and Rossby waves

GEOSAT sea level anomalies in the Western equatorial Pacific during the 1986-87 El Nino, elucidated as equatorial Kelvin and Rossby waves Delcroix Thierry auteur aut IRD Eldin Gérard auteur aut IRD Picaut Joël auteur aut IRD text conferencePaper eng text/pdf reformatted digital access Thanks to the GEOSAT altimeter data set, information on sea level changes during the 1986-87 El Nino is presented. Special emphasis is placed on the warm pool area, with an evaluation, a detailed description and tentative explanation of the observed Sea Level Anomaly (SLA) changes. Near the 165°E longitude,the onset of the 1986-87 El Nino is characterized by a rapid development of a positive (> 14 cm) equatorial SLA in november-december 1986. This feature occurs in response to an eastward wind anomaly appearing between 140°E-170°W along the equator. The wind induces a downwelling equatorial Kelvin wave with phase speed of about 2.3 m.s.-1. Thereafter, equatorial SLA remains quite constant from january to april/may 1987. In june 1987, equatorial SLA decreases to a minimum value, just after an abrupt change of the zonal wind stress anomaly, west of 165°E. Such anomaly seems to force an upwelling equatorial Kelvin wave propagating at about 2.3. m.s-1. specialized NIVEAU MARIN ANOMALIE EL NINO ONDE ROSSBY 1986 1987 PACIFIQUE EQUATORIAL OUEST 032DYNEAU Western Pacific International Meeting and Workshop on Toga Coare, Nouméa (NCL), 1989/05/24-30 259-268 Western Pacific international meeting and workshop on Toga Coare : proceedings Picaut Joël ed. edt IRD Lukas R. ed. edt IRD Delcroix Thierry ed. edt IRD Nouméa ORSTOM 1989 https://www.documentation.ird.fr/hor/fdi:30213 [F A30213] https://www.documentation.ird.fr/hor/fdi:30213 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/doc34-08/30213.pdf IRD - Base Horizon / Pleins textes 1990-07-05 2017-07-07 fdi:30213 fre