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Morel, A.; Claustre, H.; Antoine, D.; Gentili, B.. |
The optical properties of Case 1 waters have been empirically related to the chlorophyll concentration, [Chl], historically used as an index of the trophic state and of the abundance of the biological materials. The well-known natural variability around the mean statistical relationships is here examined by comparing the apparent optical properties (spectral downward irradiance attenuation and reflectance) as a function of [Chl] in two Case 1 environments, the Pacific and Mediterranean waters. These oceanic zones apparently represent two extremes of the possible bio-optical variability range around the mean. The systematic deviations, in both directions with respect to the average laws, mainly result from the differing contents in non-algal detrital... |
Tipo: Text |
Palavras-chave: Light absorption; Algal biomass; Ocean color; Chlorophyll; Sea; Phytoplankton; Model; Coefficients; Algorithms. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00209/32012/30549.pdf |
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Bellacicco, M.; Cornec, M.; Organelli, E.; Brewin, R. J. W.; Neukermans, G.; Volpe, G.; Barbieux, M.; Poteau, A.; Schmechtig, C.; D'Ortenzio, F.; Marullo, S.; Claustre, H.; Pitarch, J.. |
Understanding spatial and temporal dynamics of non-algal particles in open ocean is of the utmost importance to improve estimations of carbon export and sequestration. These particles covary with phytoplankton abundance but also accumulate independently of algal dynamics. The latter likely represents an important fraction of organic carbon, but it is largely overlooked. A possible way to study these particles is via their optical backscattering properties (b(bp)) and relationship with chlorophyll-a (Chi). To this aim, we estimate the fraction of b(bp) associated with the non-algal particle portion (b(bp)(k)) that does not covary with Chl by using a global Biogeochemical-Argo data set. We quantify the spatial, temporal, and vertical variability of b(bp)(k).... |
Tipo: Text |
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Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00676/78803/81047.pdf |
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Crombet, Y.; Leblanc, K.; Queguiner, B.; Moutin, T.; Rimmelin, P.; Ras, J.; Claustre, H.; Leblond, N.; Oriol, L.; Pujo-pay, M.. |
The silicon biogeochemical cycle has been studied in the Mediterranean Sea during late summer/early autumn 1999 and summer 2008. The distribution of nutrients, particulate carbon and silicon, fucoxanthin (Fuco), and total chlorophyll-a (TChl-a) were investigated along an eastward gradient of oligotrophy during two cruises (PROSOPE and BOUM) encompassing the entire Mediterranean Sea during the stratified period. At both seasons, surface waters were depleted in nutrients and the nutriclines gradually deepened towards the East, the phosphacline being the deepest in the easternmost Levantine basin. Following the nutriclines, parallel deep maxima of biogenic silica (DSM), fucoxanthin (DFM) and TChl-a (DCM) were evidenced during both seasons with maximal... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00133/24393/22421.pdf |
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Sauzede, R.; Lavigne, H.; Claustre, H.; Uitz, J.; Schmechtig, C.; D'Ortenzio, F.; Guinet, C.; Pesant, S.. |
In vivo chlorophyll a fluorescence is a proxy of chlorophyll a concentration, and is one of the most frequently measured biogeochemical properties in the ocean. Thousands of profiles are available from historical databases and the integration of fluorescence sensors to autonomous platforms has led to a significant increase of chlorophyll fluorescence profile acquisition. To our knowledge, this important source of environmental data has not yet been included in global analyses. A total of 268 127 chlorophyll fluorescence profiles from several databases as well as published and unpublished individual sources were compiled. Following a robust quality control procedure detailed in the present paper, about 49 000 chlorophyll fluorescence profiles were converted... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00293/40404/38962.pdf |
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D'Ortenzio, Fabrizio; Le Reste, Serge; Lavigne, Heloise; Besson, F.; Claustre, H.; Coppola, Laurent; Dufour, A.; Dutreuil, Vincent; Laes, Agathe; Leymarie, Edouard; Malarde, Damien; Mangin, A.; Migon, Christophe; Morin, P.; Poteau, A.; Prieur, L.; Raimbault, P.; Testor, Pierre. |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22555/20243.pdf |
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Le Traon, Pierre-yves; D'Ortenzio, Fabrizio; Babin, M.; Claustre, H.; Pouliquen, Sylvie; Le Reste, Serge; Thierry, Virginie; Brault, Patrice; Guigue, Michel; Le Menn, M.. |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00114/22556/20244.pdf |
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Mignot, A.; Claustre, H.; D'Ortenzio, F.; Xing, X.; Poteau, A.; Ras, J.. |
In vivo fluorescence of Chlorophyll-a (Chl-a) is a potentially useful property to study the vertical distribution of phytoplankton biomass. However the technique is presently not fully exploited as it should be, essentially because of the difficulties in converting the fluorescence signal into an accurate Chl-a concentration. These difficulties arise noticeably from natural variations in the Chl-a fluorescence relationship, which is under the control of community composition as well as of their nutrient and light status. As a consequence, although vertical profiles of fluorescence are likely the most recorded biological property in the open ocean, the corresponding large databases are underexploited. Here with the aim to convert a fluorescence profile into... |
Tipo: Text |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00248/35968/34492.pdf |
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Terrats, L.; Claustre, H.; Cornec, M.; Mangin, A.; Neukermans, G.. |
Coccolithophores (calcifying phytoplankton) form extensive blooms in temperate and subpolar oceans as evidenced from ocean‐color satellites. This study examines the potential to detect coccolithophore blooms with BioGeoChemical‐Argo (BGC‐Argo) floats, autonomous ocean profilers equipped with bio‐optical and physicochemical sensors. We first matched float data to ocean‐color satellite data of calcite concentration to select floats that sampled coccolithophore blooms. We identified two floats in the Southern Ocean, which measured the particulate beam attenuation coefficient (cp) in addition to two core BGC‐Argo variables, Chlorophyll‐a concentration ([Chl‐a]) and the particle backscattering coefficient (bbp). We show that coccolithophore blooms can be... |
Tipo: Text |
Palavras-chave: Coccolithophores; Emiliania huxleyi; Bloom detection; BGC‐Argo floats; Bio‐optics; Global ocean. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00660/77209/78652.pdf |
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Sauzède, R.; Lavigne, H.; Claustre, H.; Uitz, J.; Schmechtig, C.; D'Ortenzio, F.; Guinet, C.; Pesant, S.. |
In vivo chlorophyll a fluorescence is a proxy of chlorophyll a concentration, and is one of the most frequently measured biogeochemical properties in the ocean. Thousands of profiles are available from historical databases and the integration of fluorescence sensors to autonomous platforms has led to a significant increase of chlorophyll fluorescence profile acquisition. To our knowledge, this important source of environmental data has not yet been included in global analyses. A total of 268 127 chlorophyll fluorescence profiles from several databases as well as published and unpublished individual sources were compiled. Following a robust quality control procedure detailed in the present paper, about 49 000 chlorophyll fluorescence profiles were converted... |
Tipo: Text |
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Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00293/40448/39100.pdf |
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