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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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| Morel, A.; Gentili, B.. |
| When the nominal algorithms commonly in use in Space Agencies are applied to satellite Ocean Color data, the retrieved chlorophyll concentrations in the Mediterranean Sea are recurrently notable overestimates of the field values. Accordingly, several regionally tuned algorithms have been proposed in the past to correct for this deviation. Actually, the blueness of the Mediterranean waters is not as deep as expected from the actual (low) chlorophyll content, and the modified algorithms account for this peculiarity. Among the possible causes for such a deviation, an excessive amount of yellow substance (or of chromophoric dissolved organic matter, CDOM) has been frequently cited. This conjecture is presently tested, by using a new technique simply based on... |
| Tipo: Text |
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| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00589/70151/68131.pdf |
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| Voss, K. J.; Morel, A.; Antoine, D.. |
| The radiance viewed from the ocean depends on the illumination and viewing geometry along with the water properties, and this variation is called the bidirectional effect. This bidirectional effect depends on the inherent optical properties of the water, including the volume scattering function, and is important when comparing data from different satellite sensors. The current model of f/Q, which contains the bidirectional effect, by Morel et al. (2002) depends on modeled, not measured, water parameters, thus must be carefully validated. In this paper we combined upwelling radiance distribution data from several cruises, in varied water types and with a wide range of solar zenith angles. We compared modeled and measured L(view)/L(nadir) and found that the... |
| Tipo: Text |
Palavras-chave: Radiance distribution; Optical properties; Camera system; Reflectance; Instruments. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00209/32011/30548.pdf |
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