Title :

Biological production in two contrasted regions of the Mediterranean Sea during the oligotrophic period: an estimate based on the diel cycle of optical properties measured by BioGeoChemical-Argo profiling floats

Author(s) :

Barbieux, Marie [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Uitz, Julia [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Mignot, Alexandre [Auteur]
Roesler, Collin [Auteur]
Claustre, Hervé [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Gentili, Bernard [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Taillandier, Vincent [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
d'Ortenzio, Fabrizio [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Loisel, Hubert [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Université du Littoral Côte d'Opale [ULCO]
Poteau, Antoine [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Leymarie, Edouard [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Penkerc'H, Christophe [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]
Schmechtig, Catherine [Auteur]
Université Paris Cité [UPCité]
Bricaud, Annick [Auteur]
Laboratoire d'océanographie de Villefranche [LOV]

Journal title :

Biogeosciences

Pages :

1165-1194

Publisher :

European Geosciences Union

Publication date :

2022-02-24

ISSN :

1726-4170

HAL domain(s) :

Planète et Univers [physics]

English abstract : [en]

This study assesses marine community production based on the diel variability of bio-optical properties monitored by two BioGeoChemical-Argo (BGC-Argo) floats. Experiments were conducted in two distinct Mediterranean ...
Show more >This study assesses marine community production based on the diel variability of bio-optical properties monitored by two BioGeoChemical-Argo (BGC-Argo) floats. Experiments were conducted in two distinct Mediterranean systems, the northwestern Ligurian Sea and the central Ionian Sea, during summer months. We derived particulate organic carbon (POC) stock and gross community production integrated within the surface, euphotic and subsurface chlorophyll maximum (SCM) layers, using an existing approach applied to diel cycle measurements of the particulate beam attenuation (c<SUB>p</SUB>) and backscattering (b<SUB>bp</SUB>) coefficients. The diel cycle of c<SUB>p</SUB> provided a robust proxy for quantifying biological production in both systems; that of b<SUB>bp</SUB> was comparatively less robust. Derived primary production estimates vary by a factor of 2 depending upon the choice of the bio-optical relationship that converts the measured optical coefficient to POC, which is thus a critical step to constrain. Our results indicate a substantial contribution to the water column production of the SCM layer (16 %-42 %), which varies largely with the considered system. In the Ligurian Sea, the SCM is a seasonal feature that behaves as a subsurface biomass maximum (SBM) with the ability to respond to episodic abiotic forcing by increasing production. In contrast, in the Ionian Sea, the SCM is permanent, primarily induced by phytoplankton photoacclimation, and contributes moderately to water column production. These results clearly demonstrate the strong potential for transmissometers deployed on BGC-Argo profiling floats to quantify non-intrusively in situ biological production of organic carbon in the water column of stratified oligotrophic systems with recurring or permanent SCMs, which are widespread features in the global ocean.Show less >

Language :

Anglais

Popular science :

Non

ANR Project :

Observations de l'océan global pour l'étude et la prévision de l'océan et du climat: préparation de la nouvelle décennie d'Argo

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL