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| Bittig, Henry C.; Maurer, Tanya L.; Plant, Joshua N.; Schmechtig, Catherine; Wong, Annie P. S.; Claustre, Hervé; Trull, Thomas W.; Udaya Bhaskar, T. V. S.; Boss, Emmanuel; Dall’olmo, Giorgio; Organelli, Emanuele; Poteau, Antoine; Johnson, Kenneth S.; Hanstein, Craig; Leymarie, Edouard; Le Reste, Serge; Riser, Stephen C.; Rupan, A. Rick; Taillandier, Vincent; Thierry, Virginie; Xing, Xiaogang. |
| The Biogeochemical-Argo program (BGC-Argo) is a new profiling-float-based, ocean wide, and distributed ocean monitoring program which is tightly linked to, and has benefited significantly from, the Argo program. The community has recommended for BGC-Argo to measure six additional properties in addition to pressure, temperature and salinity measured by Argo, to include oxygen, pH, nitrate, downwelling light, chlorophyll fluorescence and the optical backscattering coefficient. The purpose of this addition is to enable the monitoring of ocean biogeochemistry and health, and in particular, monitor major processes such as ocean deoxygenation, acidification and warming and their effect on phytoplankton, the main source of energy of marine ecosystems. Here we... |
| Tipo: Text |
Palavras-chave: Ocean observation; Ocean biogeochemical cycles; Sensors; Carbon cycle; Ocean optics; Best practices; Argo. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62344/66607.pdf |
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| Johnson, Kenneth S.; Plant, Joshua N.; Dunne, John P.; Talley, Lynne D.; Sarmiento, Jorge L.. |
| Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) optical nitrate sensors deployed on profiling floats. Thirty-one floats returned 40 complete annual cycles. The mean nitrate profile from the month with the highest winter nitrate minus the mean profile from the month with the lowest nitrate yields the annual nitrate drawdown. This quantity was integrated to 200 m depth and converted to carbon using the Redfield ratio to estimate annual net community production (ANCP) throughout... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77397/78994.pdf |
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| Johnson, Kenneth S.; Plant, Joshua N.; Coletti, Luke J.; Jannasch, Hans W.; Sakamoto, Carole M.; Riser, Stephen C.; Swift, Dana D.; Williams, Nancy L.; Boss, Emmanuel; Haentjens, Nils; Talley, Lynne D.; Sarmiento, Jorge L.. |
| The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program has begun deploying a large array of biogeochemical sensors on profiling floats in the Southern Ocean. As of February 2016, 86 floats have been deployed. Here the focus is on 56 floats with quality-controlled and adjusted data that have been in the water at least 6 months. The floats carry oxygen, nitrate, pH, chlorophyll fluorescence, and optical backscatter sensors. The raw data generated by these sensors can suffer from inaccurate initial calibrations and from sensor drift over time. Procedures to correct the data are defined. The initial accuracy of the adjusted concentrations is assessed by comparing the corrected data to laboratory measurements made on samples collected... |
| Tipo: Text |
Palavras-chave: Profiling floats; Oxygen sensors; PH sensors; Nitrate sensors; Bio-optical sensors; Southern Ocean. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00662/77398/78993.pdf |
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| Johnson, Kenneth S.; Plant, Joshua N.; Maurer, Tanya L.. |
| Seawater proton concentration is a master variable that controls the air-sea gas exchange of CO2, the ability of organisms to produce calcium carbonate shells, and that tracks the production and respiration of organic carbon as CO2 is removed or added to water by biological processes. The proton concentration in seawater [H+] (mol kg-seawater-1) is typically reported as the pH = -log10 [H+]. The in situ proton concentration ranges from about 3 to 30 nmol kg-seawater-1 (7.5<pH<8.5). Seawater pH is measured from profiling floats using a Deep-Sea DuraFET pH sensor that is manufactured at MBARI (Johnson et al., 2016) or at Sea-Bird Scientific (Float pH). The core of each sensor is an Ion Sensitive Field Effect Transistor (ISFET), produced by... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00460/57195/61336.pdf |
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