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| Tedetti, Marc; Marie, Lauriane; Roettgers, Ruediger; Rodier, Martine; Van Wambeke, France; Helias, Sandra; Caffin, Mathieu; Cornet-barthaux, Veronique; Dupouy, Cecile. |
| In the framework of the VAHINE project, we investigated the spectral characteristics and the variability of dissolved and particulate chromophoric materials throughout a 23-day mesocosm experiment conducted in the south-west Pacific at the mouth of the New Caledonian coral lagoon (22 degrees 29.073 S-166 degrees 26.905 E) from 13 January to 4 February 2013. Samples were collected in a mesocosm fertilized with phosphate at depths of 1, 6 and 12m and in the surrounding waters. Light absorption coefficients of chromophoric dissolved organic matter (CDOM) [a(g) (lambda)] and particulate matter [a(p) (lambda)] were determined using a point-source integrating-cavity absorption meter (PSICAM), while fluorescent DOM (FDOM) components were determined from... |
| Tipo: Text |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00348/45893/45572.pdf |
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| Favareto, Luciane Rafaele; Rudorff, Natalia; Kampel, Milton; Frouin, Robert; Roettgers, Ruediger; Doxaran, David; Murakami, Hiroshi; Dupouy, Cecile. |
| The Eastern Lagoon of New Caledonia (ELNC) is a semi-enclosed system surrounded by an extensive coral reef barrier. The system has been suffering impacts from climate variability and anthropogenic activities, including mining exploitation. Satellite monitoring is thus an essential tool to detect such changes. The present study aimed to assess the bio-optical variability of the ELNC and examine the applicability of ocean colour algorithms, using in situ bio-optical and radiometric data, collected during the March 2014 CALIOPE 2 cruise. The chlorophyll a concentration (Chla) varied from 0.13-0.72 mg.m(-3), and the coastal stations were spectrally dominated by non-algal particles (NAP) and coloured dissolved organic matter (CDOM) (>80% of the total... |
| Tipo: Text |
Palavras-chave: Marine remote sensing reflectance; Bio-optical properties; Ocean colour algorithms; Eastern lagoon of New Caledonia; Southwest Tropical Pacific Ocean. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00481/59306/62063.pdf |
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| Roettgers, Ruediger; Doxaran, David; Dupouy, Cecile. |
| The accurate determination of light absorption coefficients of particles in water, especially in very oligotrophic oceanic areas, is still a challenging task. Concentrating aquatic particles on a glass fiber filter and using the Quantitative Filter Technique (QFT) is a common practice. Its routine application is limited by the necessary use of high performance spectrophotometers, distinct problems induced by the strong scattering of the filters and artifacts induced by freezing and storing samples. Measurements of the sample inside a large integrating sphere reduce scattering effects and direct field measurements avoid artifacts due to sample preservation. A small, portable, Integrating Cavity Absorption Meter setup (QFT-ICAM) is presented, that allows... |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00298/40949/40044.pdf |
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| Roettgers, Ruediger; Dupouy, Cecile; Taylor, Bettina B.; Bracher, Astrid; Wozniak, Slawomir B.. |
| The extent of light absorption in the near-infrared spectral region (NIR; 700-900 nm) of natural suspended particles was investigated by determining the absorption and mass-specific absorption coefficients of samples from different environments: river, coastal waters, tropical lagoon, and oceanic waters. Large amounts of sample were collected onto glass-fiber filters and measured inside the integrating sphere of a spectrophotometer. The absorption coefficient of particle suspension was also determined for visible wavelengths with a point-source integrating cavity absorption meter. Measurable nonzero particulate absorption in the NIR was determined in all samples, even in algal cultures. It was highest in the river samples (e.g., 1.7 m(-1) at 850 nm),... |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00297/40815/39842.pdf |
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