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D'Ortenzio, Fabrizio; Lavigne, Heloise; Besson, Florent; Claustre, Herve; Coppola, Laurent; Garcia, Nicole; Laes-huon, Agathe; Le Reste, Serge; Malarde, Damien; Migon, Christophe; Morin, Pascal; Mortier, Laurent; Poteau, Antoine; Prieur, Louis; Raimbault, Patrick; Testor, Pierre. |
Two profiling floats, equipped with nitrate concentration sensors were deployed in the northwestern Mediterranean from summer 2012 to summer 2013. Satellite ocean color data were extracted to evaluate surface chlorophyll concentration at float locations. Time series of mixed layer depths and nitrate and chlorophyll concentrations were analyzed to characterize the interplay between the physical-chemical and biological dynamics in the area. Deep convection (mixed layer depth > 1000 m) was observed in January–February, although high-nitrate surface concentrations could be already observed in December. Chlorophyll increase is observed since December, although high values were observed only in March. The early nitrate availability in subsurface layers, which... |
Tipo: Text |
Palavras-chave: Bio-Argo; Mediterranean; Mixed layer; Bloom onset; Nitrate concentration; Ocean color satellite. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32225/30673.pdf |
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Cuvelier, Daphne; Legendre, Pierre; Laes-huon, Agathe; Sarradin, Pierre-marie; Sarrazin, Jozee. |
During 2011, two deep-sea observatories focusing on hydrothermal vent ecology were up and running in the Atlantic (Eiffel Tower, Lucky Strike vent field) and the Northeast Pacific Ocean (NEP) (Grotto, Main Endeavour Field). Both ecological modules recorded imagery and environmental variables jointly for a time span of 23 days (7–30 October 2011) and environmental variables for up to 9 months (October 2011–June 2012). Community dynamics were assessed based on imagery analysis and rhythms in temporal variation for both fauna and environment were revealed. Tidal rhythms were found to be at play in the two settings and were most visible in temperature and tubeworm appearances (at NEP). A ∼ 6 h lag in tidal rhythm occurrence was observed between Pacific and... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00389/50069/50662.pdf |
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Daniel, Anne; Laes-huon, Agathe; Barus, Carole; Beaton, Alexander D.; Blandfort, Daniel; Guigues, Nathalie; Knockaert, Marc; Munaron, Dominique; Salter, Ian; Woodward, E. Malcolm S.; Greenwood, Naomi; Achterberg, Eric P.. |
Improved comparability of nutrient concentrations in seawater is required to enhance the quality and utility of measurements reported to global databases. Significant progress has been made over recent decades in improving the analysis and data quality for traditional laboratory measurements of nutrients. Similar efforts are required to establish high-quality data outputs from in situ nutrient sensors, which are rapidly becoming integral components of ocean observing systems. This paper suggests using the good practices routine established for laboratory reference methods to propose a harmonized set of deployment protocols and of quality control procedures for nutrient measurements obtained from in situ sensors. These procedures are intended to establish a... |
Tipo: Text |
Palavras-chave: Nutrient; EOVs; In situ sensor; Data comparability; Marine biogeochemistry; Ocean observing systems. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00603/71521/69942.pdf |
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Laes-huon, Agathe; Cathalot, Cecile; Legrand, Julien; Tanguy, Virginie; Sarradin, Pierre-marie. |
A study of the temporal dynamics of iron concentrations and temperature on a faunal assemblage at the Lucky Strike vent was performed using the Tempo ecological module at the EMSO-Azores deep-sea observatory. The CHEMINI in situ analyzer was implemented on this structure to determine reactive iron concentrations in unfiltered seawater samples along with a temperature probe. Stability tests were performed on the CHEMINI analyzer before deployment (optical module, hyperbaric tests, and deep-sea calibration) for long-term in situ analysis of reactive iron (six months, 2013–2014) at the Tour Eiffel active edifice. Recorded daily, the in situ standard (25 \mu mol.L {}^{-1} ) showed excellent reproducibility (1.07%, n=522 ), confirming satisfactory analytical... |
Tipo: Text |
Palavras-chave: Deep-sea observatory; Hydrothermal vent; In situ chemical analyzer; Iron; Monitoring the Mid-Atlantic Ridge (MoMAR). |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00342/45275/46432.pdf |
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Waeles, Mathieu; Cotte, Laura; Pernet-coudrier, Benoit; Chavagnac, V.; Cathalot, Cecile; Leleu, T.; Laes-huon, Agathe; Perhirin, Antoine; Riso, R. D.; Sarradin, Pierre-marie. |
Deep-sea hydrothermal venting is now recognized as a major source of iron (Fe), an essential trace element that controls marine productivity. However, the reactions occurring during dispersal from buoyant plumes to neutrally buoyant hydrothermal plumes are still poorly constrained. Here we report for the first time on the dissolved-particulate partition of Fe after in situ filtration at the early stage of mixing at different hydrothermal discharges, i.e., Lucky Strike (37 degrees N), TAG (26 degrees N), and Snakepit (23 degrees N) on the Mid-Atlantic Ridge. We found that hydrothermal iron is almost completely preserved (>90%) in the dissolved fraction, arguing for low iron-bearing sulfide precipitation of iron in basalt-hosted systems with low Fe:H2S... |
Tipo: Text |
Palavras-chave: Hydrothermal; Iron; Sulfide; Venting; Filtration; Precipitation. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00388/49944/50522.pdf |
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