Espinoza-Morriberon D. auteur aut IRD Echevin Vincent auteur aut IRD Colas François auteur aut IRD Tam J. auteur aut IRD Ledesma J. auteur aut IRD Vasquez L. auteur aut IRD Graco M. auteur aut IRD text journalArticle eng text/pdf born digital access Every 2-7 years, El Nino events trigger a strong decrease in phytoplankton productivity off Peru, which profoundly alters the environmental landscape and trophic chain of the marine ecosystem. Here we use a regional coupled physical-biogeochemical model to study the dynamical processes involved in the productivity changes during El Nino, with a focus on the strongest events of the 1958-2008 period. Model evaluation using satellite and in situ observations shows that the model reproduces the surface and subsurface interannual physical and biogeochemical variability. During El Nino, the thermocline and nutricline deepen significantly during the passage of coastal-trapped waves. While the upwelling-favorable wind increases, the coastal upwelling is compensated by a shoreward geostrophic near-surface current. The depth of upwelling source waters remains unchanged during El Nino but their nutrient content decreases dramatically, which, along with a mixed layer depth increase, impacts the phytoplankton growth. Offshore of the coastal zone, enhanced eddy-induced subduction during El Nino plays a potentially important role in nutrient loss. specialized PEROU PACIFIQUE 032 036 020 126 122 7 5423-5444 2017 2169-9275 https://www.documentation.ird.fr/hor/fdi:010070998 10.1002/2016jc012439 2169-9275 [F B010070998] https://www.documentation.ird.fr/hor/fdi:010070998 https://www.documentation.ird.fr/intranet/publi/2017/09/010070998.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-10-03 2023-07-11 fdi:010070998 fre