Consulta: creatorFacets:"Bhairy, Nagib"
Registros recuperados: 7
Data/hora: 08/06/2024 16:03:25

Particulate biogenic barium tracer of mesopelagic carbon remineralization in the Mediterranean Sea (PEACETIME project)
Provedor de dados: 5
Autores: Jacquet, Stéphanie Hm; Tamburini, Christian; Garel, Marc; Dufour, Aurélie; Van Vambeke, France; Le Moigne, Frédéric Ac; Bhairy, Nagib; Guasco, Sophie.
We report on the sub-basins variability of particulate organic carbon (POC) remineralization in the central and western Mediterranean Sea during a late spring period (PEACETIME cruise). POC remineralization rates (MR) were estimated using the excess non-lithogenic particulate barium (Baxs) inventories in mesopelagic waters (100–1000 m) and compared with prokaryotic heterotrophic production (PHP). MR range from 25 ± 2 to 306 ± 70 mg C m−2 d−1. Results reveal larger MR processes in the Algerian (ALG) basin compared to the Tyrrhenian (TYR) and Ionian (ION) basins. Baxs inventories and PHP also indicates that significant remineralization occurs over the whole mesopelagic layers in the ALG basin in contrast to the ION and TYR basins where remineralization is...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00652/76399/77438.pdf

Potential bioavailability of organic matter from atmospheric particles to marine heterotrophic bacteria
Provedor de dados: 5
Autores: Djaoudi, Kahina; Van Wambeke, France; Barani, Aude; Bhairy, Nagib; Chevaillier, Servanne; Desboeufs, Karine; Nunige, Sandra; Labiadh, Mohamed; Des Tureaux, Thierry Henry; Lefevre, Dominique; Nouara, Amel; Panagiotopoulos, Christos; Tedetti, Marc; Pulido-villena, Elvira.
The surface ocean receives important amounts of organic carbon from atmospheric deposition. The degree of bioavailability of this source of organic carbon will determine its impact on the marine carbon cycle. In this study, the potential availability of dissolved organic carbon (DOC) leached from both desert dust and anthropogenic aerosols to marine heterotrophic bacteria was investigated. The experimental design was based on 16 d incubations, in the dark, of a marine bacterial inoculum into artificial seawater amended with water-soluble Saharan dust (D treatment) and anthropogenic (A treatment) aerosols, so that the initial DOC concentration was similar between treatments. Glucose-amended (G) and non-amended (control) treatments were run in parallel. Over...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00677/78941/81326.pdf

Coupling physics and biogeochemistry thanks to high resolution observations of the phytoplankton community structure in the North-Western Mediterranean Sea
Provedor de dados: 5
Autores: Marrec, Pierre; Gregori, Gerald; Doglioli, Andrea M.; Dugenne, Mathilde; Della Penna, Alice; Bhairy, Nagib; Cariou, Thierry; Nunige, Sandra Helias; Lahbib, Soumaya; Rougier, Gilles; Wagener, Thibaut; Thyssen, Melilotus.
Fine-scale physical structures and ocean dynamics strongly influence and regulate biogeochemical and ecological processes. These processes are particularly challenging to describe and understand because of their ephemeral nature. The OSCAHR (Observing Submesoscale Coupling At High Resolution) campaign has been conducted in fall 2015 in which, a fine-scale structure in the North Western Mediterranean Ligurian subbasin was pre-identified using both satellite and numerical modeling data. Along the ship track, various variables were measured at the surface (temperature, salinity, chlorophyll-a and nutrients concentrations) with ADCP current velocity. We also deployed a new model of CytoSense automated flow cytometer (AFCM) optimized for small and dim cells,...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00398/50970/51726.pdf

Impact of moderate energetic fine-scale dynamics on the phytoplankton community structure in the western Mediterranean Sea
Provedor de dados: 5
Autores: Tzortzis, Roxane; Doglioli, Andrea M; Barrillon, Stéphanie; Petrenko, Anne A; D'Ovidio, Francesco; Izard, Lloyd; Thyssen, Melilotus; Pascual, Ananda; Barcelo-llull, Barbara; Cyr, Frédéric; Tedetti, Marc; Bhairy, Nagib; Garreau, Pierre; Dumas, Franck; Gregori, Gérald.
Model simulations and remote sensing observations show that ocean dynamics at fine scales (1–100 km in space, day–weeks in time) strongly influence the distribution of phytoplankton. However, only few in situ samplings have been performed and most of them in boundary currents which may not be representative of less energetic regions. The PROTEVSMED-SWOT cruise took place in the moderately energetic waters of the western Mediterranean Sea, in the southern region of the Balearic Islands. Taking advantage of near-real time satellite information, a sampling strategy was defined in order to cross a frontal zone separating different water masses. Multi-parametric in situ sensors mounted on the vessel, on a towed fish and on an ocean glider were used to sample at...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00683/79486/82078.pdf

On the barium–oxygen consumption relationship in the Mediterranean Sea: implications for mesopelagic marine snow remineralization
Provedor de dados: 5
Autores: Jacquet, Stéphanie Hm; Lefèvre, Dominique; Tamburini, Christian; Garel, Marc; Le Moigne, Frédéric Ac; Bhairy, Nagib; Guasco, Sophie.
n the ocean, remineralization rate associated with sinking particles is a crucial variable. Since the 1990s, particulate biogenic barium (Baxs) has been used as an indicator of carbon remineralization by applying a transfer function relating Baxs to O2 consumption (Dehairs's transfer function, Southern Ocean-based). Here, we tested its validity in the Mediterranean Sea (ANTARES/EMSO-LO) for the first time by investigating connections between Baxs, prokaryotic heterotrophic production (PHP) and oxygen consumption (JO2-Opt; optodes measurement). We show that (1) higher Baxs (409 pM; 100–500 m) occurs in situations where integrated PHP (PHP100/500=0.90) is located deeper, (2) higher Baxs occurs with increasing JO2-Opt, and (3) there is similar magnitude...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00648/76038/76959.pdf

Pressure-Retaining Sampler and High-Pressure Systems to Study Deep-Sea Microbes Under in situ Conditions
Provedor de dados: 5
Autores: Garel, Marc; Bonin, Patricia; Martini, Severine; Guasco, Sophie; Roumagnac, Marie; Bhairy, Nagib; Armougom, Fabrice; Tamburini, Christian.
The pelagic realm of the dark ocean is characterized by high hydrostatic pressure, low temperature, high-inorganic nutrients, and low organic carbon concentrations. Measurements of metabolic activities of bathypelagic bacteria are often underestimated due to the technological limitations in recovering samples and maintaining them under in situ environmental conditions. Moreover, most of the pressure-retaining samplers, developed by a number of different labs, able to maintain seawater samples at in situ pressure during recovery have remained at the prototype stage, and therefore not available to the scientific community. In this paper, we will describe a ready-to-use pressure-retaining sampler, which can be adapted to use on a CTD-carousel sampler. As well...
Tipo: Text
Palavras-chave: Pressure-retaining sampler; Deep sea; In situ sampling; Prokaryotic activities; Prokaryotic diversity.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00688/79992/82967.pdf

FUMSECK cruise report
Provedor de dados: 5
Autores: Barrillon, Stéphanie; Bataille, Hubert; Bhairy, Nagib; Comby, Caroline; Coulon, Théo; Doglioli, Andrea; D'Ovidio, Francesco; Fuda, Jean-luc; Gregori, Gérald; Petrenko, Anne; Ricout, Anaïs; Rousselet, Louise; Thyssen, Melilotus; Tzortzis, Roxane.
The FUMSECK cruise was a one-week technological cruise, which took place in spring 2019, in the gulf of Genoa (NW Mediterranean Sea), onboard the R/V T´ethys II. Its aim was to perform several technological tests of some instruments used for the study of the ﬁne-scale processes and dynamics. It was conducted in preparation of the BioSWOT-Med cruise in the SW Mediterranean Sea in 2022, planned as part of the “Adopt a Cross Over” initiative organising simultaneous oceanographic cruises around the world during the SWOT fast sampling phase. During FUMSECK we tested various technological innovations for the study of ﬁne-scale dynamics and their coupling with biogeochemistry.
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00636/74854/75246.pdf