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Correction of profiles of in-situ chlorophyll fluorometry for the contribution of fluorescence originating from non-algal matter ArchiMer
Xing, Xiaogang; Claustre, Herve; Boss, Emmanuel; Roesler, Collin; Organelli, Emanuele; Poteau, Antoine; Barbieux, Marie; D'Ortenzio, Fabrizio.
In situ chlorophyll fluorometers have been widely employed for more than half a century, and to date, it still remains the most used instrument to estimate chlorophyll-a concentration in the field, especially for measurements onboard autonomous observation platforms, e.g., Bio-Argo floats and gliders. However, in deep waters (> 300 m) of some specific regions, e.g., subtropical gyres and the Black Sea, the chlorophyll fluorescence profiles frequently reveal "deep sea red fluorescence" features. In line with previous studies and through the analysis of a large data set (cruise transect in the South East Pacific and data acquired by 82 Bio-Argo floats), we show that the fluorescence signal measured by a humic-like DOM fluorometer is highly correlated to...
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Ano: 2017 URL: https://archimer.ifremer.fr/doc/00661/77327/78783.pdf
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Particulate concentration and seasonal dynamics in the mesopelagic ocean based on the backscattering coefficient measured with Biogeochemical-Argo floats. ArchiMer
Poteau, Antoine; Boss, Emmanuel; Claustre, Hervé.
We explore a novel and spatially extensive data set obtained from Biogeochemical‐Argo (or BGC‐Argo) floats, containing 16,796 profiles of the particulate backscattering coefficient at 700 nm (bbp(700)) measured with three different sensors. We focus at the 900–950m depth interval (within the mesopelagic), where we found values to be relatively constant. While we find significant differences between estimates of bbp(700) obtained with different sensors (≈30% disagreement), the median values in most oceanic regions obtained with a single type of sensor are within 50% of each other and are consistent with measurements of suspended mass conducted in the early 1970s. Deviations from the quasi‐constant background value likely indicate times and locations...
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Ano: 2017 URL: https://archimer.ifremer.fr/doc/00390/50184/78793.pdf
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Preparing the New Phase of Argo: Scientific Achievements of the NAOS Project ArchiMer
Le Traon, Pierre-yves; D'Ortenzio, Fabrizio; Babin, Marcel; Leymarie, Edouard; Marec, Claudie; Pouliquen, Sylvie; Thierry, Virginie; Cabanes, Cecile; Claustre, Hervé; Desbruyeres, Damien; Lacour, Leo; Lagunas, Jose-luis; Maze, Guillaume; Mercier, Herle; Penkerc'H, Christophe; Poffa, Noe; Poteau, Antoine; Prieur, Louis; Racape, Virginie; Randelhoff, Achim; Rehm, Eric; Schmechtig, Catherine Marie; Taillandier, Vincent; Wagener, Thibaut; Xing, Xiaogang.
Argo, the international array of profiling floats, is a major component of the global ocean and climate observing system. In 2010, the NAOS (Novel Argo Observing System) project was selected as part of the French “Investissements d’Avenir” Equipex program. The objectives of NAOS were to consolidate the French contribution to Argo’s core mission (global temperature and salinity measurements down to 2000 m), and also to develop the future generation of French Argo profiling floats and prepare the next phase of the Argo program with an extension to the deep ocean (Deep Argo), biogeochemistry (BGC-Argo) and polar seas. This paper summarizes how NAOS has met its objectives. The project significantly boosted France’s contribution to Argo’s core mission by...
Tipo: Text Palavras-chave: Profiling floats; Deep ocean; Biogeochemistry; Mediterranean Sea; Arctic; Atlantic; Argo.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00654/76584/77729.pdf
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Observing mixed layer depth, nitrate and chlorophyll concentrations in the northwestern Mediterranean: A combined satellite and NO 3 profiling floats experiment ArchiMer
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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Bio-Argo floats : Data management in progress... ArchiMer
Schmechtig, Catherine; Poteau, Antoine; Claustre, Herve; D'Ortenzio, Fabrizio; Buck, Justin; Carval, Thierry.
In the context of the Bio-Argo program, a significant number of "new" biogeochemical variables are now candidate to be delivered through the Argo data stream. These variables are nitrate concentration, dissolved oxygen concentration, Chla concentration, backscattering coefficient, pH and radiometric data. Compared to the core Argo mission (P, T and 5), this diversity of new variable forces the community of biogeochemists to be very careful with respect to data management. Since three years, the community of biogeochemists thus actively participate to Argo data management meetings, in order to develop procedure for biogeochemical data compliant with Argo requirements regarding distribution policy, format, quality assessment and documentation. We illustrate...
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Ano: 2015 URL: http://archimer.ifremer.fr/doc/00254/36542/35084.pdf
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Processing bio-Argo chlorophyll-A concentration at the DAC level ArchiMer
Schmechtig, Catherine; Poteau, Antoine; Claustre, Hervé; D'Ortenzio, Fabrizio; Boss, Emmanuel.
This document does NOT address the issue of chlorophyll-a quality control (either real-time or delayed mode). As a preliminary step towards that goal, this document seeks to ensure that all countries deploying floats equipped with chlorophyll-a sensors document the data and metadata related to these floats properly. We produced this document in response to action item 3 from the first Bio-Argo Data Management meeting in Hyderabad (November 12-13, 2012). If the recommendations contained herein are followed, we will end up with a more uniform set of chlorophyll-a data within the Bio-Argo data system, allowing users to begin analyzing not only their own chlorophyll-a data, but also those of others, in the true spirit of Argo data sharing.
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Ano: 2015 URL: https://archimer.ifremer.fr/doc/00283/39468/37945.pdf
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Biogeochemical Argo: The Test Case of the NAOS Mediterranean Array ArchiMer
D’ortenzio, Fabrizio; Taillandier, Vincent; Claustre, Hervé; Prieur, Louis Marie; Leymarie, Edouard; Mignot, Alexandre; Poteau, Antoine; Penkerc’h, Christophe; Schmechtig, Catherine Marie.
The necessity of wide, global-scale observing systems for marine biogeochemistry emerged dramatically in the last decade. A global network based on Biogeochemical (BGC) Argo floats is considered to be one of the most promising approaches for reaching this goal. As a first step, pilot studies were encouraged to test the feasibility of a global BGC-Argo array, to consolidate the methods and practices under development, and to set up the array’s characteristics. A pilot study in The Mediterranean Sea—deemed a suitable candidate for a test case because it combines a relatively large diversity of oceanic BGC conditions in a reduced open-ocean basin—was consequently approved as a part of the “Novel Argo ocean Observing System” (NAOS) project, a French national...
Tipo: Text Palavras-chave: BGC-Argo floats; Mediterranean; Bioregions; Ocean color; Physical biological interactions.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00618/73031/72145.pdf
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Organic Carbon Export and Loss Rates in the Red Sea ArchiMer
Kheireddine, Malika; Dall'Olmo, Giorgio; Ouhssain, Mustapha; Krokos, George; Claustre, Hervé; Schmechtig, Catherine; Poteau, Antoine; Zhan, Peng; Hoteit, Ibrahim; Jones, Burton H..
The export and fate of organic carbon in the mesopelagic zone are still poorly understood and quantified due to lack of observations. We exploited data from a biogeochemical‐Argo float that was deployed in the Red Sea to study how a warm and hypoxic environment can affect the fate of the organic carbon in the ocean's interior. We observed that only 10% of the particulate organic carbon (POC) exported survived at depth due to remineralization processes in the upper mesopelagic zone. We also found that POC exported was rapidly degraded in a first stage and slowly in a second one, which may be dependent on the palatability of the organic matter. We observed that apparent oxygen utilization (AOU)‐based loss rates (a proxy of the remineralization of total...
Tipo: Text Palavras-chave: Carbon export; Carbon loss rates; Mesopelagic zone; Temperature; Oxygen; Tropical ecosystem.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00655/76730/77877.pdf
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Processing BGC-Argo CDOM concentration at the DAC level ArchiMer
Schmechtig, Catherine; Organelli, Emanuele; Poteau, Antoine; Claustre, Hervé; D'Ortenzio, Fabrizio.
In the open ocean, Colored Dissolved Organic Matter (CDOM) is the fraction of the total Dissolved Organic Matter (DOM), composed by a mixture of chemically complex algal degradation products that interact with light. CDOM absorbs solar radiation in the UV and visible ranges (Bricaud et al., 1981) and, if illuminated, re-emits light as fluorescence (i.e., FDOM; Coble 1996). These optical measurements can be used as proxies of CDOM concentration. Whereas CDOM absorption measurements are given by the entire pool of the organic matter, FDOM measurements detect only sub-fractions. Depending on excitation and emission wavelengths of the fluorometer, FDOM can represent the fresh-material produced by microbial degradation of phytoplankton cells and/or from...
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Ano: 2017 URL: http://archimer.ifremer.fr/doc/00434/54541/55910.pdf
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Two databases derived from BGC-Argo float measurements for marine biogeochemical and bio-optical applications ArchiMer
Organelli, Emanuele; Barbieux, Marie; Claustre, Herve; Schmechtig, Catherine; Poteau, Antoine; Bricaud, Annick; Boss, Emmanuel; Briggs, Nathan; Dall'Olmo, Giorgio; D'Ortenzio, Fabrizio; Leymarie, Edouard; Mangin, Antoine; Obolensky, Grigor; Penkerc'H, Christophe; Prieur, Louis; Roesler, Collin; Serra, Romain; Uitz, Julia; Xing, Xiaogang.
Since 2012, an array of 105 Biogeochemical-Argo (BGC-Argo) floats has been deployed across the world's oceans to assist in filling observational gaps that are required for characterizing open-ocean environments. Profiles of biogeochemical (chlorophyll and dissolved organic matter) and optical (single-wavelength particulate optical backscattering, downward irradiance at three wavelengths, and photosynthetically available radiation) variables are collected in the upper 1000 m every 1 to 10 days. The database of 9837 vertical profiles collected up to January 2016 is presented and its spatial and temporal coverage is discussed. Each variable is quality controlled with specifically developed procedures and its time series is quality-assessed to identify issues...
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Ano: 2017 URL: https://archimer.ifremer.fr/doc/00662/77389/79010.pdf
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French National Report on Argo - 2018 ArchiMer
Maze, Guillaume; Cabanes, Cecile; Carval, Thierry; Claustre, Hervé; Coatanoan, Christine; D'Ortenzio, Fabrizio; Kolodziejczyk, Nicolas; Lebreton, Nathanaele; Le Reste, Serge; Le Traon, Pierre-yves; Poteau, Antoine; Poffa, Noe; Pouliquen, Sylvie; Schmechtig, Catherine; Thierry, Virginie.
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00484/59523/62497.pdf
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Hydrography and biogeochemistry dedicated to the Mediterranean BGC-Argo network during a cruise with RV Tethys 2 in May 2015 ArchiMer
Taillandier, Vincent; Wagener, Thibaut; D'Ortenzio, Fabrizio; Mayot, Nicolas; Legoff, Herve; Ras, Josephine; Coppola, Laurent; Pasqueron De Fommervault, Orens; Schmechtig, Catherine; Diamond, Emilie; Bittig, Henry; Lefevre, Dominique; Leymarie, Edouard; Poteau, Antoine; Prieur, Louis.
We report on data from an oceanographic cruise, covering western, central and eastern parts of the Mediterranean Sea, on the French research vessel Tethys 2 in May 2015. This cruise was fully dedicated to the maintenance and the metrological verification of a biogeochemical observing system based on a fleet of BGC-Argo floats. During the cruise, a comprehensive data set of parameters sensed by the autonomous network was collected. The measurements include ocean currents, seawater salinity and temperature, and concentrations of inorganic nutrients, dissolved oxygen and chlorophyll pigments. The analytical protocols and data processing methods are detailed, together with a first assessment of the calibration state for all the sensors deployed during the...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00677/78943/81333.pdf
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Application file for renewal of the 'National Observation Service' label (INSU/CNRS) 2020-2024: SNO Argo-France ArchiMer
Kolodziejczyk, Nicolas; Cabanes, Cecile; D'Ortenzio, Fabrizio; Maze, Guillaume; Pouliquen, Sylvie; Poteau, Antoine; Schmechtig, Catherine; Thierry, Virginie.
Application file for renewal of labeling as National Observation Service of SNO Argo-France with INSU for the period 2020-2024. This document presents the results of SNO Argo France's activities over the 2015-2019 labeling period; and sets targets for the period 2020-2024.
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00499/61055/64484.pdf
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Processing Bio-Argo nitrate concentration at the DAC Level ArchiMer
Johnson, Ken; Pasqueron De Fommervault, Orens; Serra, Romain; D'Ortenzio, Fabrizio; Schmechtig, Catherine; Claustre, Hervé; Poteau, Antoine.
The only method used to date to measure dissolved nitrate concentration (NITRATE) with sensors mounted on profiling floats is based on the absorption of light at ultraviolet wavelengths by nitrate ion (Johnson and Coletti, 2002; Johnson et al., 2010; 2013; D’Ortenzio et al., 2012). Nitrate has a modest UV absorption band with a peak near 210 nm, which overlaps with the stronger absorption band of bromide, which has a peak near 200 nm. In addition, there is a much weaker absorption due to dissolved organic matter and light scattering by particles (Ogura and Hanya, 1966). The UV spectrum thus consists of three components, bromide, nitrate and a background due to organics and particles. The background also includes thermal effects on the instrument and slow...
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Ano: 2018 URL: http://archimer.ifremer.fr/doc/00350/46121/55922.pdf
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First success of ProvBIO floats ArchiMer
Le Reste, Serge; Andre, Xavier; Claustre, Herve; D'Ortenzio, Fabrizio; Poteau, Antoine.
The anthropogenic greenhouse effect and the associated temperature rise of the planet represent the main challenging issue for the Earth sciences of the next century. Marine ecosystems are a key component of the Earth system, as they modulate the transfer of greenhouse gases (mainly CO2) to the ocean surface. Moreover, oceanic ecosystems mitigate the effects of anthropogenic carbon injection into the atmosphere, via the so-called “biological pump”. Ocean biogeochemistry is hence confronted to a major challenge: the determination of the extent and efficiency of the climatic feedback of the carbon “biological pump” within the context of climate change. A new type of float, the “ProvBio”, has been developed jointly by Ifremer and the French company KANNAD,...
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Ano: 2009 URL: http://archimer.ifremer.fr/doc/00219/32998/31455.pdf
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Processing Argo measurement timing information at the DAC level ArchiMer
Bittig, Henry C.; Schmechtig, Catherine; Rannou, Jean-philippe; Poteau, Antoine.
Thermal lag or sensor time response corrections (e.g., [1]) require knowledge of the time of each individual sensor observation. In the Argo data system, the float's trajectory file is the natural place to put measurement timing information. Historically, only few levels of a float's profile have been timed, and DACs stored these sparse timed levels of the float profile in the trajectory already. Depending on the DAC, all measured paramters are stored with the timing information, or just the PRES variable is stored together with the time. With the need to have all observations timed, this approach leads to the following problems: a) With all parameters stored together with the timing information and put into the trajectory file, the trajectory file in...
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Ano: 2017 URL: http://archimer.ifremer.fr/doc/00369/47998/48031.pdf
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Processing BGC-Argo Radiometric data at the DAC level ArchiMer
Schmechtig, Catherine; Poteau, Antoine; Claustre, Herve; D’ortenzio, Fabrizio.
Presently, radiometers can be implemented on profiling floats to estimate some radiometric measurements. Hereafter we briefly describe the principle of this method and several configurations of the OCR500 series instruments. These measurements can be radiance or irradiance at different wavelengths and in different directions (upward or downward). The Photosynthetically Available Radiation (PAR) is also measured as it represents the solar radiation that photosynthetic organisms are able to use in the process of photosynthesis. At the moment all radiometric sensors implemented on floats are developed by the Satlantic Company and are of the OCR serie. These radiometers combine three wavelengths for irradiance measurements together with a measurement of the...
Tipo: Text Palavras-chave: Argo; Bgc-argo; Optic.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00404/51541/52133.pdf
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Recommendations for obtaining unbiased chlorophyll estimates from in situ chlorophyll fluorometers: A global analysis of WET Labs ECO sensors ArchiMer
Roesler, Collin; Uitz, Julia; Claustre, Herve; Boss, Emmanuel; Xing, Xiaogang; Organelli, Emanuele; Briggs, Nathan; Bricaud, Annick; Schmechtig, Catherine; Poteau, Antoine; D'Ortenzio, Fabrizio; Ras, Josephine; Drapeau, Susan; Haentjens, Nils; Barbieux, Marie.
Chlorophyll fluorometers provide the largest in situ global data set for estimating phytoplankton biomass because of their ease of use, size, power consumption, and relatively low price. While in situ chlorophyll a (Chl) fluorescence is proxy for Chl a concentration, and hence phytoplankton biomass, there exist large natural variations in the relationship between in situ fluorescence and extracted Chl a concentration. Despite this large natural variability, we present here a global validation data set for the WET Labs Environmental Characterization Optics (ECO) series chlorophyll fluorometers that suggests a factor of 2 overestimation in the factory calibrated Chl a estimates for this specific manufacturer and series of sensors. We base these results on...
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Ano: 2017 URL: https://archimer.ifremer.fr/doc/00384/49552/50046.pdf
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Enhancement of phytoplankton biomass leeward of Tahiti as observed by Biogeochemical-Argo floats ArchiMer
Sauzède, Raphaëlle; Martinez, Elodie; Maes, Christophe; De Fommervault, Orens Pasqueron; Poteau, Antoine; Mignot, Alexandre; Claustre, Hervé; Uitz, Julia; Oziel, Laurent; Maamaatuaiahutapu, Keitapu; Rodier, Martine; Schmechtig, Catherine; Laurent, Victoire.
The South Pacific Subtropical Gyre (SPSG) is a vast and remote oceanic system where the variability in phytoplankton biomass and production is still largely uncertain due to the lack of in situ biogeochemical observations. The SPSG is an oligotrophic environment where the ecosystem is controlled predominantly by nutrient depletion in surface waters. However, this dynamic is altered in the vicinity of islands where increased biological activity occurs (i.e. the island mass effect, IME). This study mainly focuses on in situ observations which show evidence of an IME leeward of Tahiti (17.7°S - 149.5°W), French Polynesia. Physical and biogeochemical observations collected with two Biogeochemical-Argo profiling floats are used to investigate the dynamics of...
Tipo: Text Palavras-chave: Phytoplankton biomass; Biogeochemical-Argo floats; Island mass effect; South Pacific Subtropical Gyre.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00599/71130/69445.pdf
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French National Report on Argo - 2017 ArchiMer
Maze, Guillaume; Cabanes, Cecile; Carval, Thierry; Claustre, Hervé; Coatanoan, Christine; D'Ortenzio, Fabrizio; Kolodziejczyk, Nicolas; Lebreton, Nathanaele; Poteau, Antoine; Le Reste, Serge; Schmechtig, Catherine; Le Traon, Pierre-yves; Poffa, Noe; Pouliquen, Sylvie; Thierry, Virginie.
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00435/54642/56063.pdf
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