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Variabilité biooptique à différentes échelles spatiales et temporelles dans l'Atlantique nord-est : interprétations biogéochimiques

Abstract : This study has been driven by necessity to be able to describe biogeochemical variability on the same resolution as physical parameters. Optical profilers were used to measure high frequency inherent optical properties of the water column. Comparison to discretes samples collected simultaneously with our data allows us to convert IOPs at one wavelength into biogeochemical quantities. We have estimated chlorophyll a, total particulate carbon concentrations and the vertical distribution of colored dissolved organic matter (CDOM). The qualitative nature of particulate and dissolved matter has been studied combining several optical coefficients or analyzing their spectral dependency. In a laboratory experiment, a population of calcifying organisms (Emiliania huxleyi) was cultured under controlled conditions to characterize its optical properties and evolution after increasing atmospheric pCO2 from actual level (360 ppm) to the level predicted for the end of the century (700 ppm). During three campaigns between continental Portugal and Azores, we mapped biooptical mesoscale variability over three seasonally important periods : end of winter, spring and end of summer. High resolution observations have evidenced several relationships between the hydrological and biogeochemical characteristics of water column. In addition, instrumental deployment along transects using a towed undulating system (Tow-Yo, 2 nm resolution) has lead to a better understanding of the influence of mesocale eddies.
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https://tel.archives-ouvertes.fr/tel-00004148
Contributor : Davy Merien <>
Submitted on : Monday, January 12, 2004 - 3:31:11 PM
Last modification on : Thursday, December 10, 2020 - 10:52:46 AM
Long-term archiving on: : Friday, April 2, 2010 - 7:22:53 PM

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  • HAL Id : tel-00004148, version 1

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Davy Merien. Variabilité biooptique à différentes échelles spatiales et temporelles dans l'Atlantique nord-est : interprétations biogéochimiques. Autre. Université Pierre et Marie Curie - Paris VI, 2003. Français. ⟨tel-00004148⟩

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