Maintaining of the Oxygen Minimum Zone in the Eastern Tropical Pacific based on a high-resolution coupled physical/biogeochemical model
Ivonne Montes, Elodie Gutknecht, Aurélien Paulmier, Boris Dewitte, Isabelle Dadou, and
Véronique Garçon
The Eastern Tropical Pacific hosts the Humboldt Current System, the most productive eastern boundary upwelling of the world oceans. This region encompasses an extended
Oxygen Minimum Zone (OMZ), which is maintained due to the sluggish oceanic circulation and high organic matter decomposition consuming dissolved oxygen. Remote variability exerted by the subsurface Equatorial Current System influences the area by carrying oxygenated waters which contribute to the OMZ ventilation. Our interest is to investigate, using a coupled physical/biogeochemical model (ROMS-BioBus), the physical and biogeochemical processes involved in the transport and maintaining of the OMZ off Peru.
Preliminary results under climatological conditions show that the OMZ core presents combined dynamics driven by the alongshore currents located below 50m depth: the core upper part exhibits an oxygen loss associated to the Peru Chile Undercurrent (PCUC) while the lower gradient is associated to a source with the equatorward flow below the PCUC.