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| Pizarro-koch, Matias; Pizarro, Oscar; Dewitte, Boris; Montes, Ivonne; Ramos, Marcel; Paulmier, Aurelien; Garcon, Veronique. |
| We investigate the seasonal variability of the southern tip (30 degrees-38 degrees S) of the eastern South Pacific oxygen minimum zone (OMZ) based on a high horizontal resolution (1/12 degrees) regional coupled physical-biogeochemical model simulation. The simulation is validated by available in situ observations and the OMZ seasonal variability is documented. The model OMZ, bounded by the contour of 45 mu M, occupies a large volume (4.5x10(4) km(3)) during the beginning of austral winter and a minimum (3.5x10(4) km(3)) at the end of spring, just 1 and 2 months after the southward transport of the Peru-Chile Undercurrent (PCUC) is maximum and minimum, respectively. We showed that the PCUC significantly impacts the alongshore advection of dissolved oxygen... |
| Tipo: Text |
Palavras-chave: Oxygen minimum zone; Eddy fluxes; Peru-Chile Undercurrent; Oxygen budget; Eastern South Pacific. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00688/79991/82948.pdf |
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| Montes, Ivonne; Dewitte, Boris; Gutknecht, Elodie; Paulmier, Aurelien; Dadou, Isabelle; Oschlies, Andreas; Garcon, Veronique. |
| 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... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00688/79998/82951.pdf |
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| Bretagnon, Marine; Paulmier, Aurelien; Garcon, Veronique; Dewitte, Boris; Illig, Serena; Leblond, Nathalie; Coppola, Laurent; Campos, Fernando; Velazco, Federico; Panagiotopoulos, Christos; Oschlies, Andreas; Martin Hernandez-ayon, J.; Maske, Helmut; Vergara, Oscar; Montes, Ivonne; Martinez, Philippe; Carrasco, Edgardo; Grelet, Jacques; Desprez-de-gesincourt, Olivier; Maes, Christophe; Scouarnec, Lionel. |
| The fate of the organic matter (OM) produced by marine life controls the major biogeochemical cycles of the Earth's system. The OM produced through photosynthesis is either preserved, exported towards sediments or degraded through remineralisation in the water column. The productive eastern boundary upwelling systems (EBUSs) associated with oxygen minimum zones (OMZs) would be expected to foster OM preservation due to low O-2 conditions. But their intense and diverse microbial activity should enhance OM degradation. To investigate this contradiction, sediment traps were deployed near the oxycline and in the OMZ core on an instrumented moored line off Peru. Data provided high-temporal-resolution O-2 series characterising two seasonal steady states at the... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00486/59764/62889.pdf |
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| Hernandez-ayon, Jose M.; Paulmier, Aurélien; Garcon, Veronique; Sudre, Joel; Montes, Ivonne; Chapa-balcorta, Cecilia; Durante, Giovanni; Dewitte, Boris; Maes, Christophe; Bretagnon, Marine. |
| The oxygen minimum zone (OMZ) of Peru is recognized as a source of CO2 to the atmosphere due to upwelling that brings water with high concentrations of dissolved inorganic carbon (DIC) to the surface. However, the influence of OMZ dynamics on the carbonate system remains poorly understood given a lack of direct observations. This study examines the influence of a coastal Eastern South Pacific OMZ on carbonate system dynamics based on a multidisciplinary cruise that took place in 2014. During the cruise, onboard DIC and pH measurements were used to estimate pCO2 and to calculate the calcium carbonate saturation state (Ω aragonite and calcite). South of Chimbote (9°S), water stratification decreased and both the oxycline and carbocline moved from 150 m depth... |
| Tipo: Text |
Palavras-chave: OMZ; DIC; PH; Omega aragonite; Upwelling Peruvian system. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70004/67919.pdf |
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| Garcon, Veronique; Karstensen, Johannes; Palacz, Artur; Telszewski, Maciej; Aparco Lara, Tony; Breitburg, Denise; Chavez, Francisco; Coelho, Paulo; Cornejo-d'Ottone, Marcela; Santos, Carmen; Fiedler, Bjoern; Gallo, Natalya D.; Gregoire, Marilaure; Gutierrez, Dimitri; Hernandez-ayon, Martin; Isensee, Kirsten; Koslow, Tony; Levin, Lisa; Marsac, Francis; Maske, Helmut; Mbaye, Baye C.; Montes, Ivonne; Naqvi, Wajih; Pearlman, Jay; Pinto, Edwin; Pitcher, Grant; Pizarro, Oscar; Rose, Kenneth; Shenoy, Damodar; Van Der Plas, Anja; Vito, Melo R.; Weng, Kevin. |
| Multidisciplinary ocean observing activities provide critical ocean information to satisfy ever-changing socioeconomic needs and require coordinated implementation. The upper oxycline (transition between high and low oxygen waters) is fundamentally important for the ecosystem structure and can be a useful proxy for multiple observing objectives connected to eastern boundary systems (EBSs) that neighbor oxygen minimum zones (OMZs). The variability of the oxycline and its impact on the ecosystem (VOICE) initiative demonstrates how societal benefits drive the need for integration and optimization of biological, biogeochemical, and physical components of regional ocean observing related to EBS. In liaison with the Global Ocean Oxygen Network, VOICE creates a... |
| Tipo: Text |
Palavras-chave: Oxygen minimum zones; Oxycline; Ocean observing system; Multidisciplinary; Readiness level; Ecosystem. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00659/77112/78546.pdf |
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| Montes, Ivonne; Colas, Francois; Capet, Xavier; Schneider, Wolfgang. |
| The connections between the Equatorial Current System and the Peru Current System in the eastern tropical Pacific (ETP) are examined with a primitive equations eddy-resolving regional model. The quasi-equilibrium solutions reproduce three eastward equatorial subsurface currents of interest: the Equatorial Undercurrent (EUC, located between 1 degrees N and 1 degrees S), the primary Southern Subsurface Countercurrent (pSSCC, between 3 degrees and 4 degrees S) and, farther south the secondary Southern Subsurface Countercurrent (sSSCC, between 7 degrees and 8 degrees S). Using a Lagrangian tracking procedure, the fate of these currents in the ETP and their contribution to the Peru-Chile Undercurrent (PCUC) are studied. Lagrangian diagnostics show that for the... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12438/9249.pdf |
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