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Messié, M.; Petrenko, A.; Doglioli, A.m.; Aldebert, C.; Martinez, Elodie; Koenig, G.; Bonnet, S.; Moutin, T.. |
In oligotrophic gyres of the tropical ocean, islands can enhance phytoplankton biomass and create hotspots of productivity and biodiversity. This “Island Mass Effect” (IME) is typically identified by increased chlorophyll concentrations next to an island. Here we use a simple plankton model in a Lagrangian framework to represent an unexplained open ocean bloom, demonstrating how islands could have triggered it remotely. This new type of IME, termed “delayed IME”, occurs when nitrate is limiting, N:P ratios are low, and excess phosphate and iron remain in water masses after an initial bloom associated to a “classical” IME. Nitrogen fixers then slowly utilize leftover phosphate and iron while water masses get advected away, resulting in a bloom decoupled in... |
Tipo: Text |
Palavras-chave: Island mass effect; Lagrangian analysis; Nitrogen fixation; Nutrient supply; Oligotrophic ocean; Phytoplankton bloom. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00600/71162/69489.pdf |
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Kersale, M.; Doglioli, A.m.; Petrenko, A. A.. |
The oceanic circulation around the Hawaiian archipelago is characterized by a complex circulation and the presence of mesoscale eddies west of the islands. These eddies typically develop and persist for weeks to several months in the area during persistent trade winds conditions. A series of numerical simulations on the Hawaiian region has been done in order to examine the relative importance of wind, inflow current and topographic forcing on the general circulation and the generation of eddies. Moreover, numerical cyclonic eddies are compared with the one observed during the cruise E-FLUX (Dickey et al., 2008). Our study demonstrates the need for all three forcings (wind, inflow current and topography) to reproduce the known oceanic circulation. In... |
Tipo: Text |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00215/32587/31051.pdf |
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Rousselet, L.; Doglioli, A.m.; De Verneil, A.; Pietri, A.; Della Penna, A.; Berline, L.; Marrec, P.; Grégori, G.; Thyssen, M.; Carlotti, F.; Barillon, S.; Simon‐bot, F.; Bonal, M.; D'Ovidio, F.; Petrenko, A.. |
Vertical velocities can be estimated indirectly from in situ observations by theoretical frameworks like the ω‐equation. Direct measures of vertical exchanges are challenging due to their typically ephemeral spatiotemporal scales. In this study we address this problem with an adaptive sampling strategy coupling various biophysical instruments. We analyze the 3‐D organization of a cyclonic mesoscale structure finely sampled during the OSCAHR (Observing Submesoscale Coupling At High Resolution) cruise in the Ligurian Sea during fall 2015. The observations, acquired with a Moving Vessel Profiler (MVP), highlight a subsurface low‐salinity layer (≃ 50 m), as well as rising isopycnals, generated by geostrophic cyclonic circulation, in the structure's center.... |
Tipo: Text |
Palavras-chave: High-resolution reconstructions of 3-D fields; Vertical velocities estimated with omega-equation; Particle distribution as a tracer for vertical advection. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00490/60214/63567.pdf |
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Pinazo, Christel; Ross, Oliver; Diaz, F.; Doglioli, A.m.; D'Ortenzio, F.; Estournel, C.; Forget, P.; Garnier, Valerie; Gutknecht, E.; Kersale, M.; Kessouri, F.; Lathuilière, C.; Marie, Louis; Marmain, J.; Marsaleix, P.; Perruche, C.; Petrenko, A.; Reffray, G.; Sourisseau, Marc; Taillandier, V.; Taupier-letage, I.; Testor, P.; Thouvenin, Benedicte; Ulses, C.; Eldin, G.. |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00292/40336/41772.pdf |
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