Drushka K. auteur aut IRD Bellenger H. auteur aut IRD Guilyardi E. auteur aut IRD Lengaigne Matthieu auteur aut IRD Vialard Jérôme auteur aut IRD Madec G. auteur aut IRD text journalArticle eng text/pdf born digital access We investigate the processes responsible for the intraseasonal displacements of the eastern edge of the western Pacific warm pool (WPEE), which appear to play a role in the onset and development of El Nino events. We use 25 years of output from an ocean general circulation model experiment that is able to accurately capture the observed displacements of the WPEE, sea level anomalies, and upper ocean zonal currents at intraseasonal time scales in the western and central Pacific Ocean. Our results confirm that WPEE displacements driven by westerly wind events (WWEs) are largely controlled by zonal advection. This paper has also two novel findings: first, the zonal current anomalies responsible for the WPEE advection are driven primarily by local wind stress anomalies and not by intraseasonal wind-forced Kelvin waves as has been shown in most previous studies. Second, we find that intraseasonal WPEE fluctuations that are not related to WWEs are generally caused by intraseasonal variations in net heat flux, in contrast to interannual WPEE displacements that are largely driven by zonal advection. This study hence raises an interesting question: can surface heat flux-induced zonal WPEE motions contribute to El Nino-Southern Oscillation evolution, as WWEs have been shown to be able to do?. specialized Westerly wind events Western Pacific warm pool Air-sea interaction El Nino Intraseasonal variability PACIFIQUE OUEST 032 021 44 3-4 735-755 2015 0930-7575 https://www.documentation.ird.fr/hor/fdi:010063939 10.1007/s00382-014-2297-z 0930-7575 [F B010063939] https://www.documentation.ird.fr/hor/fdi:010063939 https://www.documentation.ird.fr/intranet/publi/2015/03/010063939.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-04-07 2017-08-23 fdi:010063939 fre