Chabert P., Echevin, Aumont Olivier, Person Renaud, Hourdin C., Pous S., Machu Eric, Capet X. (2024). Bottom-up propagation of synoptic wind intensification and relaxation in the planktonic ecosystem of the South Senegalese Upwelling Sector. Journal of Plankton Research, [Early access], p. fbae054 [ p.]. ISSN 0142-7873.
Titre du document
Bottom-up propagation of synoptic wind intensification and relaxation in the planktonic ecosystem of the South Senegalese Upwelling Sector
Chabert P., Echevin, Aumont Olivier, Person Renaud, Hourdin C., Pous S., Machu Eric, Capet X.
Source
Journal of Plankton Research, 2024,
[Early access], p. fbae054 [ p.] ISSN 0142-7873
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.
Plan de classement
Ecologie, systèmes aquatiques [036]
;
Etudes, transformation, conservation du milieu naturel [082]
