Montes I., Dewitte Boris, Gutknecht E., Paulmier Aurélien, Dadou I., Oschlies A., Garcon V. (2014). High-resolution modeling of the Eastern Tropical Pacific oxygen minimum zone : sensitivity to the tropical oceanic circulation. Journal of Geophysical Research. Oceans, 119 (8), p. 5515-5532. ISSN 2169-9275.
Titre du document
High-resolution modeling of the Eastern Tropical Pacific oxygen minimum zone : sensitivity to the tropical oceanic circulation
Montes I., Dewitte Boris, Gutknecht E., Paulmier Aurélien, Dadou I., Oschlies A., Garcon V.
Journal of Geophysical Research. Oceans, 2014,
119 (8), p. 5515-5532 ISSN 2169-9275
The connection between the equatorial mean circulation and the oxygen minimum zone (OMZ) in the Eastern Tropical Pacific is investigated through sensitivity experiments with a high-resolution coupled physical-biogeochemical model. A validation against in situ observations indicates a realistic simulation of the vertical and horizontal oxygen distribution by the model. Two sets of climatological open-boundary conditions for the physical variables, which differ slightly with respect to the intensity and vertical structure of the Equatorial Current System, are shown to lead to contrasting characteristics of the simulated OMZ dynamics. From a Lagrangian perspective, the mean differences near the coast originate to a large extent from the different transport of deoxygenated waters by the secondary Tsuchiya Jet (secondary Southern Subsurface Countercurrent, sSSCC). The O-2 budget further indicates a large difference in the balance between tendency terms, with advection exhibiting the largest difference between both simulations, which is shown to result from both linear and nonlinear advection. At regional scale, we also find that the variability of the physical contribution to the rate of O-2 change is one order of magnitude larger than the variability associated with the biogeochemical contribution, which originates from internal high-frequency variability. Overall our study illustrates the large sensitivity of the OMZ dynamics to the equatorial circulation.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche 
Limnologie physique / Océanographie physique