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Berline, Léa; Doglioli, Andrea Michelangelo; Petrenko, Anne; Barrillon, Stéphanie; Espinasse, Boris; Le Moigne, Frederic A. C.; Simon-bot, François; Thyssen, Melilotus; Carlotti, François. |
In the upper layers of the Ionian Sea, young Mediterranean Atlantic Waters (MAW) flowing eastward from the Sicily channel meet old MAW. In May 2017, during the PEACETIME cruise, fluorescence and particle content sampled at high resolution revealed unexpected heterogeneity in the central Ionian. Surface salinity measurements, together with altimetry-derived and hull-mounted ADCP currents, describe a zonal pathway of AW entering the Ionian Sea, consistent with the so-called cyclonic mode in the North Ionian Gyre. The ION-Tr transect, located ~19–20° E–~36° N turned out to be at the crossroad of three water masses, mostly coming from the west, north and from an isolated anticyclonic eddy northeast of ION-Tr. Using Lagrangian numerical simulations, we suggest... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00677/78886/81182.pdf |
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Trueblood, Jonathan, V; Nicosia, Alessia; Engel, Anja; Zancker, Birthe; Rinaldi, Matteo; Freney, Evelyn; Thyssen, Melilotus; Obernosterer, Ingrid; Dinasquet, Julie; Belosi, Franco; Tovar-sanchez, Antonio; Rodriguez-romero, Araceli; Santachiara, Gianni; Guieu, Cecile; Sellegri, Karine. |
Ice-nucleating particles (INPs) have a large impact on the climate-relevant properties of clouds over the oceans. Studies have shown that sea spray aerosols (SSAs), produced upon bursting of bubbles at the ocean surface, can be an important source of marine INPs, particularly during periods of enhanced biological productivity. Recent mesocosm experiments using natural seawater spiked with nutrients have revealed that marine INPs are derived from two separate classes of organic matter in SSAs. Despite this finding, existing parameterizations for marine INP abundance are based solely on single variables such as SSA organic carbon (OC) or SSA surface area, which may mask specific trends in the separate classes of INP. The goal of this paper is to improve the... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/79985/82974.pdf |
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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,... |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00398/50970/51726.pdf |
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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... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00683/79486/82078.pdf |
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Bonato, Simon; Christaki, Urania; Lefebvre, Alain; Lizon, Fabrice; Thyssen, Melilotus; Artigas, Luis Felipe. |
The distribution of phytoplankton (from pico-to microphytoplankton) was investigated, at single-cell level and at high spatial resolution, during an oceanographic cruise across the eastern English Channel (EEC) between April 27 and 29, 2012. Seawater was continuously collected from surface waters and analysed on board at high frequency (one sample every 10 min), by using a new generation of pulse-shape recording scanning flow cytometer (CytoSense, Cytobuoy©). A Bray-Curtis matrix analysis based on phytoplankton composition allowed the discrimination of 4 communities. Within these communities, abundance, cell size as well as single cell and total red fluorescence of 8 phytoplankton groups were measured. Picoeukaryotes and Synechococcus spp. cells dominated... |
Tipo: Text |
Palavras-chave: Phytoplankton dynamics; High spatial resolution; Flow cytometer; Red fluorescence. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00248/35885/34406.pdf |
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Freney, Evelyn; Sellegri, Karine; Nicosia, Alessia; Trueblood, Jonathan T; Rinaldi, Matteo; Williams, Leah R; Prévôt, André Sh; Thyssen, Melilotus; Gregori, Gerald; Haëntjens, Nils; Dinasquet, Julie; Obernosterer, Ingrid; Van Wambeke, France; Engel, Anja; Zancker, Birthe; Desboeufs, Karine; Asmi, Eija; Timmonen, Hilka; Guieu, Cécile. |
The organic mass fraction from sea spray aerosol (SSA) is currently a subject of intense research. The majority of this research is dedicated to measurements in ambient air, although recently a small number of studies have additionally focused on nascent sea spray aerosol. This work presents measurements collected during a five-week cruise in May and June 2017 in the central and western Mediterranean Sea, an oligotrophic marine region with low phytoplankton biomass. Surface seawater was continuously pumped into a bubble bursting apparatus to generate nascent sea spray aerosol. Size distributions were measured with a differential mobility particle sizer (DMPS). Chemical characterization of the submicron aerosol was performed with a time of flight aerosol... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00688/80017/82995.pdf |
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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. |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00636/74854/75246.pdf |
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Sellegri, Karine; Nicosia, Alessia; Freney, Evelyn; Uitz, Julia; Thyssen, Melilotus; Grégori, Gérald; Engel, Anja; Zäncker, Birthe; Haëntjens, Nils; Mas, Sébastien; Picard, David; Saint-macary, Alexia; Peltola, Maija; Rose, Clémence; Trueblood, Jonathan; Lefevre, Dominique; D’anna, Barbara; Desboeufs, Karine; Meskhidze, Nicholas; Guieu, Cécile; Law, Cliff S.. |
One pathway by which the oceans influence climate is via the emission of sea spray that may subsequently influence cloud properties. Sea spray emissions are known to be dependent on atmospheric and oceanic physicochemical parameters, but the potential role of ocean biology on sea spray fluxes remains poorly characterized. Here we show a consistent significant relationship between seawater nanophytoplankton cell abundances and sea-spray derived Cloud Condensation Nuclei (CCN) number fluxes, generated using water from three different oceanic regions. This sensitivity of CCN number fluxes to ocean biology is currently unaccounted for in climate models yet our measurements indicate that it influences fluxes by more than one order of magnitude over the range of... |
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Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00669/78077/80312.pdf |
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