Chabert P. auteur aut IRD Echevin auteur aut IRD Aumont Olivier auteur aut IRD Person Renaud auteur aut IRD Hourdin C. auteur aut IRD Pous S. auteur aut IRD Machu Eric auteur aut IRD Capet X. auteur aut IRD text journalArticle eng Synoptic intensification or relaxation of upwelling favorable winds are major sources of variability in eastern boundary upwelling systems. This study aims to investigate their impact on the planktonic ecosystem of the South Senegalese Upwelling Sector (SSUS), located south of the Cape Verde peninsula over a wide and shallow continental shelf. Numerical experiments using a three-dimensional coupled physical-biogeochemical model with four plankton functional types simulated the response of the coastal planktonic ecosystem to idealized synoptic (similar to 10 days) wind intensification and relaxation of the same amplitude. We find that these perturbations induce spatio-temporal oscillations of plankton concentrations. Zooplankton response occurred with a time lag that manifests itself in space as an equatorward/downstream shift in distribution relative to phytoplankton. Overall, the transmission of the synoptic perturbation from the physics to zooplankton is characterized by a damping in relative anomalies. All these elements and the weakness of the asymmetries in the biogeochemical/planktonic ecosystem responses between intensification and relaxation events support the hypothesis that synoptic variability has limited impact on the climatological state of low-latitude upwelling systems such as the SSUS. specialized planktonic ecosystem synoptic coastal upwelling modeling SENEGAL ATLANTIQUE 036 082 [Early access] fbae054 [ p.] 2024 0142-7873 https://www.documentation.ird.fr/hor/PAR00028450 10.1093/plankt/fbae054 0142-7873 https://www.documentation.ird.fr/hor/PAR00028450 IRD - Base Horizon / Pleins textes 2024-12-04 2025-11-06 PAR00028450 fre