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Author Yan Axel Gomez Coutouly file  openurl
  Title Un peuplement antérieur à 20 000 ans en Amérique ? Type Book Chapter
  Year 2021 Publication « Et pourtant elle tourne ! » blocages épistémologiques en archéologie. Colloque organisé par Laure Fontana et Sophie A. de Beaune, (Projets collectifs ArScAn), 18-19 novembre 2021, Campus de Nanterre Université, France Abbreviated Journal  
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  Corporate Author Thesis Bachelor's thesis  
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  Notes Approved yes  
  Call Number Serial 8692  
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Author Alexis Burr openurl 
  Title Etude de la fermeture des pores lors de la densification du névé polaire // Investigation of pore closure during polar firn densification Type Thesis
  Year 2021 Publication Université de bretagne occidentale Abbreviated Journal  
  Volume Thesis started in October 2021 Issue Pages  
  Keywords 540 Anisotropie Anisotropy Densification Discrete simulations Fermeture des pores Firn Névé Névés Pore closure Simulations discrètes Tomographie X Viscoplasticité X-Ray tomography  
  Abstract .La densification du névé en glace est un processus essentiel à comprendre pour interpréter les enregistrements climatiques. Une bonne connaissance des mécanismes permet une datation précise de l'air capturé dans la glace lors de la fermeture des pores. Celle-ci est plus vieille que l'air capturé à cause du transport des gaz dans la colonne de névé plus rapide que la densification de celui-ci. Cette différence d'âge entre la glace et le gaz est généralement appelé le Δage. La densification de la neige consiste en un processus complexe de réarrangement de grains, de frittage et de déformation viscoplastique. Bien que le comportement viscoplastique du cristal de glace soit fortement anisotrope, les modèles de densification actuels ne tiennent pas compte de cette anisotropie. De plus, le caractère granulaire du névé affecte aussi sa densification. La relation entre la fermeture des pores et les mécanismes microstructuraux sous-jacents est encore méconnue. Le but de cette thèse est d'incorporer l'aspect granulaire ainsi que l'anisotropie du cristal de glace dans une approche de modélisation innovante de la densification. Des expériences sur l'indentation viscoplastique de cylindres monocristallins de glace ont été réalisées pour proposer une loi de contact basée sur la théorie de l'indentation, et prenant en compte la déformation préférentielle du cristal de glace sur les plans basaux. Cette loi de contact a été implémentée dans un code utilisant la méthode des éléments discrets pour prédire la densification du névé.La micro-tomographie aux rayons X a été utilisée pour caractériser ex situ le névé polaire en trois dimensions à différentes étapes de la densification (ρ= 0.55-0.88 g/cm3), i.e. pour différentes profondeurs (~23 à 130m). Une étude fine de la fermeture des pores et de différentes caractéristiques morphologiques et physiques a été réalisée pour les sites polaires Dome C et Lock In. Des essais mécaniques ont aussi été réalisés in situ sur du névé extrait de Dome C dans le but de modéliser la densification du névé. Les observations microstructurales des expériences ex situ et in situ révèlent d'importantes différences dues aux vitesses relativement importantes utilisées lors des essais mécaniques. Ces vitesses rapides permettent de découpler la contribution des cinétiques de diffusion de la contribution viscoplastique de la déformation. Les effets de ces contributions sur la morphologie des pores et leurs fermetures sont discutés. Pour caractériser la fermeture des pores, cette thèse propose un indice de connectivité définit par le ratio entre le volume du plus gros pore sur la porosité totale. En effet, cet indice est plus approprié lors de l'utilisation de la tomographie aux rayons X que le ratio de pores fermés pour prédire la densité au close-off.  
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  Notes Approved yes  
  Call Number Serial 8347  
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Author Grégoire Mureau openurl 
  Title Étude des impacts des événements extrêmes sur le massif dunaire de la plage de Sanvík (Islande) Type Master 1
  Year 2021 Publication Université de bretagne occidentale Abbreviated Journal  
  Volume https://www-iuem.univ-brest.fr/pops/attachments/26 Issue Pages 62 p.  
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  Notes Approved yes  
  Call Number Serial 8383  
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Author Sarah Albertin, Slimane Bekki, Joël Savarino openurl 
  Title Nitrogen isotopes (δ15N) and oxygen isotope anomalies (Δ17O, δ18O) in atmospheric nitrogen dioxide : a new perspective for isotopic constraints on oxidation and aerosols formation processes Type Communication
  Year 2021 Publication EGU General Assembly 2021, 10-30 april 2021, Vienna, Austria Abbreviated Journal  
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  ISSN EGU21-2634 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8511  
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Author Albertin, S., Savarino, J., Bekki, S., T. Roberts, T., Barret, B., Mao, J., Simpson, W., Law, K. openurl 
  Title Isotopic constraints on the sources and fate of atmospheric nitrate in Fairbanks, Alaska: preliminary results of the pre-ALPACA campaign Type Communication
  Year 2021 Publication Paces meeting, may 2021 Abbreviated Journal  
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  Notes Approved yes  
  Call Number Serial 8513  
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Author Morten Frederiksen, Olivier Gilg, Glenn Yannic doi  openurl
  Title Cross-icecap spring migration confirmed in a high-Arctic seabird, the Ivory Gull Pagophila eburnea Type Journal
  Year 2021 Publication Ibis Abbreviated Journal  
  Volume 163 Issue 2 Pages 706-714  
  Keywords ecological barrier Greenland icecap high-altitude migration  
  Abstract Seabirds rarely cross major terrestrial barriers during seasonal migration, possibly because they have a limited ability to build up fat stores. For the first time, we tracked two Ivory Gulls with GPS loggers during spring migration from the wintering area in Davis Strait to the breeding colony in north-east Greenland. While one bird migrated in March around the southern tip of Greenland, the other delayed migration until May and crossed the Greenland icecap north of 70°N, covering 1345 km in 29 h. Several aspects of the crossing were noteworthy: the track was remarkably direct, the bird made several stops (totalling 6 h) on the icecap, and the bird increased its flying altitude to nearly 3000 m over West Greenland and > 4000 m over East Greenland.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0019-1019 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 6348  
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Author Francesco Enrichi, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Carlo Barbante doi  openurl
  Title Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid Type Journal
  Year 2021 Publication Applied Sciences Abbreviated Journal  
  Volume 11 Issue 9 Pages 3830  
  Keywords Beyond EPICA drilling Estisol ice cores  
  Abstract To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, EstisolTM 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of “drying”, the cores have a dry feel, handling them do not give “wet” gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the “drying” process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates.  
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  Notes Approved yes  
  Call Number Serial 8247  
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Author Morgan Godard openurl 
  Title Caractérisation du comportement alimentaire de l'éléphant de mer Mirounga leonina et liens avec les structures physiques sub-mésoéchelles (1-10km) dans l'océan Austral : une approche par analyse de données fonctionnelles Type Thesis
  Year 2021 Publication Thèse de doctorat en Océanographie Abbreviated Journal  
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  Abstract De nombreuses questions restent en suspens quant aux relations existantes entre les processus biologiques et physiques dans l'océan Austral. Pour répondre à ces questions, des enregistreurs électroniques sont déployés sur des prédateurs marins, et notamment sur des éléphants de mer austraux. Ces enregistreurs échantillonnent une grande variété de données physiques, biologies ou comportementales à haute fréquence générant ainsi une quantité considérable d’information. L’ensemble de ces données sont dites fonctionnelles car elles présentent un caractère commun : elles évoluent selon un continuum, qu’il soit spatial ou temporel. L’objectif de cette thèse est donc double, il s’agit d’étudier l’activité alimentaire de femelles éléphant de mer en relation avec les processus physiques de l’océan austral, tout en intégrant le caractère fonctionnel des données échantillonnées. Les résultats obtenus montrent que (1) par rapport aux méthodes classiquement employées, les méthodes d’analyse de données fonctionnelles permettent d’identifier une plus grande variété de comportements de plongées au sens biologique défini. (2) Ces approches fonctionnelles sont plus adaptées pour des données aux fréquences d’échantillonnage variable. (3) L’analyse de données fonctionnelles nous permet également d’accéder à la densité de nos individus, reflet de leur condition corporelle, et les comportements de plongées qu’ils adoptent ont une influence réelle sur cette condition corporelle, à différentes échelles de temps. (4) Il existe une relation entre les caractéristiques des masses d’eau rencontrées par les femelles éléphants de mer et les plongées qu’elles effectuent.  
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  Notes Approved yes  
  Call Number Serial 7727  
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Author Martin Tournier, Pauline Goulet, Nadège Fonvieille, David Nerini, Mark Johnson, Christophe Guinet doi  openurl
  Title A novel animal-borne miniature echosounder to observe the distribution and migration patterns of intermediate trophic levels in the Southern Ocean Type Journal
  Year 2021 Publication Journal of Marine Systems Abbreviated Journal  
  Volume 223 Issue Pages 103608  
  Keywords Biologging Diel vertical migration Functional data analysis Marine acoustics Micronekton Sonar tag  
  Abstract Despite expanding in-situ observations of marine ecosystems by new-generation sensors, information about intermediate trophic levels remains sparse. Indeed, mid-trophic levels, while encompassing a broad range of zooplankton and micronekton organisms that represent a key component of marine ecosystems and sustain large and diverse communities of marine predators, are challenging to sample and identify. In this study, we examined whether an animal-borne miniature active echosounder can provide information on the distribution and movements of mid-trophic level organisms. If so, such a sonar tag, harnessing the persistent diving behaviour of far-ranging marine mammals, could greatly increase the density of data on this under-studied biome. High-frequency (1.5 MHz) sonar tags were deployed simultaneously with oceanographic tags on two southern elephant seals (Mirounga leonina), at the Kerguelen Islands and Valdés Peninsula (Argentina), and recorded acoustic backscatter while the seals foraged respectively in the Indian and the Atlantic sectors of the Southern Ocean. The backscatter varied widely over time and space, and the seals attempted to capture only a small fraction of the insonified targets. Diel vertical migration patterns were clearly identifiable in the data, reinforcing our confidence in the ability of the sonar tags to detect living mid-trophic organisms along with possibly sinking biological detritus. Moreover, CTD tags attached to the same animals indicated how the abundance, size distribution, and diel migration behaviour of acoustic targets varied with water bodies. These preliminary results demonstrate the potential for animal-borne sonars to provide detailed in-situ information. Further validation effort will make it a valuable tool to refine the estimation of carbon export fluxes as well as for assessing the variation of mid-trophic level biomass according to oceanographic domains and seasons.  
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  ISSN 0924-7963 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 8260  
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Author Clive R. McMahon, Fabien Roquet, Sophie Baudel, Mathieu Belbeoch, Sophie Bestley, Clint Blight, Lars Boehme, Fiona Carse, Daniel P. Costa, Michael A. Fedak, Christophe Guinet, Robert Harcourt, Emma Heslop, Mark A. Hindell, Xavier Hoenner, Kim Holland, Mellinda Holland, Fabrice R. A. Jaine, Tiphaine Jeanniard du Dot, Ian Jonsen, Theresa R. Keates, Kit M. Kovacs, Sara Labrousse, Philip Lovell, Christian Lydersen, David March, Matthew Mazloff, Megan K. McKinzie, Mônica M. C. Muelbert, Kevin O’Brien, Lachlan Phillips, Esther Portela, Jonathan Pye, Stephen Rintoul, Katsufumi Sato, Ana M. M. Sequeira, Samantha E. Simmons, Vardis M. Tsontos, Victor Turpin, Esmee van Wijk, Danny Vo, Mia Wege, Frederick Gilbert Whoriskey, Kenady Wilson, Bill Woodward doi  openurl
  Title Animal Borne Ocean Sensors – AniBOS – An Essential Component of the Global Ocean Observing System Type Journal
  Year 2021 Publication Frontiers in Marine Science Abbreviated Journal  
  Volume 8 Issue Pages  
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  Abstract Marine animals equipped with biological and physical electronic sensors have produced long-term data streams on key marine environmental variables, hydrography, animal behavior and ecology. These data are an essential component of the Global Ocean Observing System (GOOS). The Animal Borne Ocean Sensors (AniBOS) network aims to coordinate the long-term collection and delivery of marine data streams, providing a complementary capability to other GOOS networks that monitor Essential Ocean Variables (EOVs), essential climate variables (ECVs) and essential biodiversity variables (EBVs). AniBOS augments observations of temperature and salinity within the upper ocean, in areas that are under-sampled, providing information that is urgently needed for an improved understanding of climate and ocean variability and for forecasting. Additionally, measurements of chlorophyll fluorescence and dissolved oxygen concentrations are emerging. The observations AniBOS provides are used widely across the research, modeling and operational oceanographic communities. High latitude, shallow coastal shelves and tropical seas have historically been sampled poorly with traditional observing platforms for many reasons including sea ice presence, limited satellite coverage and logistical costs. Animal-borne sensors are helping to fill that gap by collecting and transmitting in near real time an average of 500 temperature-salinity-depth profiles per animal annually and, when instruments are recovered (∼30% of instruments deployed annually, n = 103 ± 34), up to 1,000 profiles per month in these regions. Increased observations from under-sampled regions greatly improve the accuracy and confidence in estimates of ocean state and improve studies of climate variability by delivering data that refine climate prediction estimates at regional and global scales. The GOOS Observations Coordination Group (OCG) reviews, advises on and coordinates activities across the global ocean observing networks to strengthen the effective implementation of the system. AniBOS was formally recognized in 2020 as a GOOS network. This improves our ability to observe the ocean’s structure and animals that live in them more comprehensively, concomitantly improving our understanding of global ocean and climate processes for societal benefit consistent with the UN Sustainability Goals 13 and 14: Climate and Life below Water. Working within the GOOS OCG framework ensures that AniBOS is an essential component of an integrated Global Ocean Observing System.  
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  ISSN 2296-7745 ISBN Medium  
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  Notes Approved yes  
  Call Number Serial 8326  
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