Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author David Byrne, Jeff Polton, Colin Bell doi  isbn
openurl 
  Title Creation of a global tide analysis dataset: Application of NEMO and an offline objective analysis scheme Type Journal
  Year 2021 Publication Journal of Operational Oceanography Abbreviated Journal  
  Volume Issue Pages (down) 1-14  
  Keywords  
  Abstract The accurate prediction of tides is vital for the operation of many industries, early warning of coastal flooding and scientific understanding of ocean processes. In this paper, we describe the creation method of a global dataset of tidal harmonics using NEMO (Nucleus for European Modelling of the Ocean) for the first time and an offline objective analysis scheme. Data are assimilated as part of a post-processing step, reducing the computational resources required. A reduced ensemble of tidal harmonics is generated, where each member is run for a shorter period of time than a central background state. This ensemble is used to estimate a single background covariance state, which is used for analysis. Output is validated using an ensemble of objective analyses. For each ensemble member, random selections of observations are omitted and validation is performed at these locations. Improvements in both Mean Absolute Error (MAE) and correlation coefficients (R2) are seen across all 6 of the largest diurnal and semi-diurnal constituents. MAEs in amplitude and phase are reduced by up to 78% and 89%, respectively, and correlations by as much as 0.14. In addition, the majority of locations (between 70 and 80%) see significant improvement.  
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1755-876X ISBN 1755-876X Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8338  
Permanent link to this record
 

 
Author Pamela E. Michael, Chris Wilcox, Christophe Barbraud, Karine Delord, Michael Sumner, Henri Weimerskirch doi  isbn
openurl 
  Title Dynamic enforcement of bycatch via reproductive value can increase theoretical efficiency Type Journal
  Year 2021 Publication Marine Policy Abbreviated Journal  
  Volume 132 Issue Pages (down) 104684  
  Keywords Albatross Bycatch Dynamic enforcement Dynamic ocean management Monitoring Reproductive value  
  Abstract Managing marine systems is challenging, as many marine species are highly mobile. Albatross exemplify this paradigm, overlapping multiple threats at sea, including bycatch. The typical characterization of bycatch, the number of individuals, ignores the long-term, population-wide repercussions of bycatch. Including an estimate of the reproductive value (RV, the loss of future reproductive contributions, given bycatch) is a complementary tool, incorporating the population-wide repercussions of bycatch. While bycatch management via dynamic spatial management allows management boundaries to move, it requires monitoring and enforcement to be effective. We provide a proof of concept to optimize bycatch enforcement activities by dynamically targeting areas of concentrated future productivity characterized by RV. This paper examined a population of black-browed albatross (Thalassarche melanophris) as a case study. We calculate RV and apply it to at-sea distributions. This creates spatiotemporally explicit surfaces used to prioritize times and locations for bycatch mitigation enforcement. Dynamic enforcement has greater theoretical efficiency than static enforcement, but this difference decreases with increasing population-wide RV subject to enforcement. Though there are implementation challenges, many can be reduced with existing tools providing various opportunities. Incorporating RV when characterizing the impacts of bycatch on a population and strategically applying dynamic bycatch enforcement based on RV can be a powerful, efficient component of dynamic ocean management.  
  Programme 109  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0308-597X ISBN 0308-597X Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8342  
Permanent link to this record
 

 
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 (down)  
  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.  
  Programme 1216  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8347  
Permanent link to this record
 

 
Author Lucie Aulus-Giacosa openurl 
  Title Spatio-temporal evolution of life history traits related to dispersal. Brown trout (Salmo trutta L.) colonization of the sub-Antarctic Kerguelen Islands. // Evolution de l'anadromie chez la truite commune (Salmo trutta) L. dans le cadre de l'expansion des populations introduites dans les îles Kerguelen. Type Thesis
  Year 2021 Publication Thèse de doctorat en Physiologie et Biologie des Organismes – Populations -Interactions Abbreviated Journal  
  Volume Issue Pages (down)  
  Keywords  
  Abstract Grâce à ses capacités dispersives et adaptatives, la truite commune (Salmo trutta L.), poisson anadrome facultatif, est un bon candidat à la colonisation de nouveaux milieux. L'introduction de l'espèce dans les années 1950 dans les îles subantarctiques de Kerguelen fournit un modèle d'étude unique pour comprendre les causes et les mécanismes de la dispersion, grâce à l'étude des traits d'histoire de vie en lien avec la migration (e.g. croissance, âge à la migration). L'étude de leur évolution temporelle le long d'un front de colonisation est le cœur de ce travail de thèse. A travers l’étude des écailles recueillies dans le cadre de ce programme à long terme, les histoires de vie de près de 5000 poissons ont été reconstruites. Ce travail démontre l’importance de la méthodologie utilisée afin de reconstruire les traits de vie individuel. La modélisation de l’évolution de la croissance en eau douce, de la taille à l’âge et de l’âge à la première migration démontre que des processus évolutifs sont en œuvre dans les populations en expansion. Notamment, le ralentissement de la croissance avec le temps ainsi que la diminution de la taille à l’âge le long du front de colonisation laissent à penser que la capacité de dispersion diminue à mesure que les populations sont en marges de la zone d’expansion. L’évolution de la valeur seuil à la première migration confirme ce résultat, et illustre l’importance de la plasticité phénotypique et de l’adaptation locale dans le choix de la tactique migratoire. Toutefois, l’approche menée dans ce manuscrit se concentre sur l’évolution de la migration, et bénéficierait de l’étude de l’évolution conjointe des traits impliqués dans la valeur sélective (balance coûts-bénéfices), tels que la reproduction, ou la croissance en mer.  
  Programme 1041  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8354  
Permanent link to this record
 

 
Author Pengcheng Wang, Natacha B. Bernier, Keith R. Thompson, Tsubasa Kodaira doi  openurl
  Title Evaluation of a global total water level model in the presence of radiational S2 tide Type Journal
  Year 2021 Publication Ocean Modelling Abbreviated Journal  
  Volume 168 Issue Pages (down) 101893  
  Keywords NEMO Radiational and gravitational tide Storm surge Tidal nudging Total water level  
  Abstract The development of a computationally efficient scheme for predicting the global distribution of total water level (TWL) is discussed. The ocean model is barotropic, has a horizontal grid spacing of 1/12°, and is based on the NEMO modeling framework. It is forced by the gravitational potential and hourly atmospheric fields for 2008. Hourly time spacing was required to resolve the S2 tide in global air pressure and wind. The predicted tide in water deeper than 400 m was nudged to TPXO8 “observations” of tidal elevation or current using a scheme called tidal nudging (Kodaira et al., 2019). The benefit of nudging horizontal velocity in the momentum equation, compared to sea level in the continuity equation, is discussed. Tidal nudging is shown to improve tidal predictions of sea level at the coast, particularly at the S2 tidal frequency. The predicted radiational S2 tide in sea level forced solely by the S2 tide in global air pressure reaches amplitudes exceeding 80 cm. Decreasing the time spacing of the air pressure forcing from 1 h to 3 h reduces the S2 amplitude in air pressure by a factor of 0.82, consistent with expectations based on Fourier analysis. This highlights the importance of using hourly atmospheric forcing when predicting the global sea level response to atmospheric forcing. The radiational S2 tide in sea level is subject to strong nonlinear interaction with the gravitational tide, leading to a pronounced attenuation of the radiational S2 tide. The attenuation is explained by an increase in effective bottom friction at the S2 frequency due to the presence of the gravitational tide. Four schemes for predicting TWL are evaluated to quantify the impact of tidal nudging and nonlinear interaction of tide and surge. Using TWLs observed by 304 coastal tide gauges, we show it is necessary to include both tidal nudging and nonlinear interaction. Plans for the further development of an operational flood forecast system for the Canadian coast, based on the above model, are discussed.  
  Programme 688  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1463-5003 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8356  
Permanent link to this record
 

 
Author Lisa-Marie Mazzolo openurl 
  Title Evolution de la calotte glaciaire du Svalbard par altimétrie laser Type Master 2
  Year 2021 Publication Abbreviated Journal  
  Volume Issue Pages (down)  
  Keywords  
  Abstract  
  Programme 337  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8357  
Permanent link to this record
 

 
Author Stefan Osterwalder, Sarrah M. Dunham-Cheatham, Beatriz Ferreira Araujo, Olivier Magand, Jennie L. Thomas, Foteini Baladima, Katrine Aspmo Pfaffhuber, Torunn Berg, Lei Zhang, Jiaoyan Huang, Aurélien Dommergue, Jeroen E. Sonke, Mae Sexauer Gustin doi  openurl
  Title Fate of Springtime Atmospheric Reactive Mercury: Concentrations and Deposition at Zeppelin, Svalbard Type Journal
  Year 2021 Publication ACS Earth and Space Chemistry Abbreviated Journal  
  Volume 5 Issue 11 Pages (down) 3234-3246  
  Keywords  
  Abstract Mid-latitude atmospheric elemental mercury (Hg) emissions undergo extensive oxidation to reactive Hg (RM) compounds during Arctic polar sunrise, resulting in enhanced atmospheric deposition that impacts Arctic marine wildlife and humans. It has been difficult to estimate RM dry deposition, because RM concentrations, compounds, and their deposition velocities are ill-defined. Here, we investigate RM concentrations sampled with membrane-based methods and find these to exceed denuder-based RM detection by 5 times at the Zeppelin Observatory on Svalbard (March 26–July 24, 2019). Measured dry deposition of gaseous oxidized Hg was about half of the modeled RM deposition, demonstrating that particulate-bound Hg was an important component of dry deposition. Using thermal membrane desorption, RM chemistry was found to be dominated by Hg–Cl/Br (51%) and Hg–N (45%) compounds. Back-trajectory analysis indicated that Hg–Br/Cl compounds were predominantly advected from within the marine boundary layer (sea ice exposure), while Hg–N originated from the free troposphere. Weekly average RM compound-specific dry deposition velocities ranged from 0.12 to 0.49 cm s–1, with a net RM dry deposition of 1.9 μg m–2 (1.5–2.5 μg m–2; 95% confidence interval) that exceeds the mean annual Hg wet deposition flux in Svalbard. Overall, we find that springtime atmospheric RM deposition has been underestimated in the Arctic marine environment.  
  Programme 1028  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8361  
Permanent link to this record
 

 
Author Lara D. Shepherd, Colin M. Miskelly, Yves Cherel, Alan J. D. Tennyson doi  openurl
  Title Genetic identification informs on the distributions of vagrant Royal (Eudyptes schlegeli) and Macaroni (Eudyptes chrysolophus) Penguins Type Journal
  Year 2021 Publication Polar Biology Abbreviated Journal  
  Volume 44 Issue 12 Pages (down) 2299-2306  
  Keywords Antarctica Eudyptes chrysolophus Eudyptes schlegeli Genetic identification Penguin distribution Predation  
  Abstract Understanding the movements of animals that spend much of their life at sea is difficult but important for effective conservation. Determining the at-sea distributions of Macaroni (Eudyptes chrysolophus) and Royal (Eudyptes schlegeli) Penguins poses particular challenges, including their occurrence in remote locations and difficulties in species identification owing to overlap in morphological characters, particularly in immature birds. Here we use DNA sequencing to examine vagrant Macaroni and Royal Penguins from Antarctica and New Zealand in order to improve understanding of their non-breeding distributions. Our sampling included samples from living birds, museum specimens and scavenged penguin remains recovered from the stomachs of Antarctic toothfish (Dissostichus mawsoni) caught north of the Ross Sea. Mitochondrial control region (HVRI) sequences indicated that the two samples from New Zealand were likely Royal Penguins as were the scavenged penguins. Both Macaroni and Royal Penguins were detected at Terre Adélie, Antarctica, despite the nearest breeding colony of Macaroni Penguins being 4000 km away. We provide the first evidence of Royal Penguins reaching the Ross Dependency. All but one of the vagrants were immature birds, supporting suggestions that this age group is the most likely to disperse large distances from the breeding colonies. Our study demonstrates how DNA sequences can assist in identifying taxa with similar or overlapping morphologies, as well as fragmentary bird remains.  
  Programme 109  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1432-2056 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8365  
Permanent link to this record
 

 
Author Martin Beal, Maria P. Dias, Richard A. Phillips, Steffen Oppel, Carolina Hazin, Elizabeth J. Pearmain, Josh Adams, David J. Anderson, Michelle Antolos, Javier A. Arata, José Manuel Arcos, John P. Y. Arnould, Jill Awkerman, Elizabeth Bell, Mike Bell, Mark Carey, Ryan Carle, Thomas A. Clay, Jaimie Cleeland, Valentina Colodro, Melinda Conners, Marta Cruz-Flores, Richard Cuthbert, Karine Delord, Lorna Deppe, Ben J. Dilley, Herculano Dinis, Graeme Elliott, Fernanda De Felipe, Jonathan Felis, Manuela G. Forero, Amanda Freeman, Akira Fukuda, Jacob González-Solís, José Pedro Granadeiro, April Hedd, Peter Hodum, José Manuel Igual, Audrey Jaeger, Todd J. Landers, Matthieu Le Corre, Azwianewi Makhado, Benjamin Metzger, Teresa Militão, William A. Montevecchi, Virginia Morera-Pujol, Leia Navarro-Herrero, Deon Nel, David Nicholls, Daniel Oro, Ridha Ouni, Kiyoaki Ozaki, Flavio Quintana, Raül Ramos, Tim Reid, José Manuel Reyes-González, Christopher Robertson, Graham Robertson, Mohamed Salah Romdhane, Peter G. Ryan, Paul Sagar, Fumio Sato, Stefan Schoombie, R. Paul Scofield, Scott A. Shaffer, Nirmal Jivan Shah, Kim L. Stevens, Christopher Surman, Robert M. Suryan, Akinori Takahashi, Vikash Tatayah, Graeme Taylor, David R. Thompson, Leigh Torres, Kath Walker, Ross Wanless, Susan M. Waugh, Henri Weimerskirch, Takashi Yamamoto, Zuzana Zajkova, Laura Zango, Paulo Catry doi  openurl
  Title Global political responsibility for the conservation of albatrosses and large petrels Type Journal
  Year 2021 Publication Science Advances Abbreviated Journal  
  Volume 7 Issue 10 Pages (down) eabd7225  
  Keywords  
  Abstract Migratory marine species cross political borders and enter the high seas, where the lack of an effective global management framework for biodiversity leaves them vulnerable to threats. Here, we combine 10,108 tracks from 5775 individual birds at 87 sites with data on breeding population sizes to estimate the relative year-round importance of national jurisdictions and high seas areas for 39 species of albatrosses and large petrels. Populations from every country made extensive use of the high seas, indicating the stake each country has in the management of biodiversity in international waters. We quantified the links among national populations of these threatened seabirds and the regional fisheries management organizations (RFMOs) which regulate fishing in the high seas. This work makes explicit the relative responsibilities that each country and RFMO has for the management of shared biodiversity, providing invaluable information for the conservation and management of migratory species in the marine realm.  
  Programme 109  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8369  
Permanent link to this record
 

 
Author Hugo Saiz, David Renault, Sara Puijalon, Miguel Barrio, Mathilde Bertrand, Matteo Tolosano, Aurélien Pierre, Charly Ferreira, Clémentine Prouteau, Anne-Kristel Bittebiere doi  openurl
  Title Huff and puff and blow down: invasive plants traits response to strong winds at the Southern Oceanic Islands Type Journal
  Year 2021 Publication Oikos Abbreviated Journal  
  Volume 130 Issue 11 Pages (down) 1919-1929  
  Keywords environmental filter functional traits hypervolume Iles Kerguelen intraspecific variability mechanical stress  
  Abstract Invasions constitute a major driver of biodiversity changes. Insular plant communities are particularly vulnerable to invasions and are relevant models for investigating mechanisms supporting the establishment and spread of introduced plants. Terrestrial flora of sub-Antarctic islands must often thrive in highly windy habitats, thus imposing strong mechanical constraints on individuals. Many alien plants at the sub-Antarctic islands are of tropical or temperate origins, where they were exposed to less stringent wind conditions. As wind likely represents a strong environmental filter for the successful establishment and further geographic spread of plants, they should have developed responses to resist and successfully colonize the Iles Kerguelen. We studied responses to wind of three herbaceous species that are invasive at Iles Kerguelen. We sampled plant individuals at different locations, under windy and sheltered conditions. Traits related to wind avoidance and tolerance and to resource acquisition were measured. We additionally assessed individual performance (biomass) to determine the consequences of trait variations. We focused on trait mean and variance, in particular, through the calculation of hypervolumes. This study emphasized that wind has important effects on plant economics spectrum, including traits involved in mechanical avoidance and light acquisition, with varying strategies, which seem to depend on the biological type of the species (grass versus non-grass). Wind generally reduces individual performance, and this negative effect is not direct but operates through the modification of plant trait values. Furthermore, analyses performed at the hypervolume scale indicate that not only functional trait mean but also its variability account for plant performance. The existence of contrasting growth strategies to cope with local environmental conditions suggests that invaders will be able to occupy different niches, which may ultimately impact local communities. Our results highlight the importance of considering multi-traits responses to meaningfully capture plant adjustments to stress.  
  Programme 136  
  Campaign  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1600-0706 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8372  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print