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Author Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B. A. Slangen, Guy Wöppelmann doi  openurl
  Title Constraining 20th-Century Sea-Level Rise in the South Atlantic Ocean Type Journal
  Year 2021 Publication Journal of Geophysical Research: Oceans Abbreviated Journal  
  Volume 126 Issue 3 Pages e2020JC016970  
  Keywords (down) data rescue salt-marsh proxies sea-level changes South Atlantic tide gauges  
  Abstract Sea level in the South Atlantic Ocean has only been measured at a small number of tide-gauge locations, which causes considerable uncertainty in 20th-century sea-level trend estimates in this basin. To obtain a better-constrained sea-level trend in the South Atlantic Ocean, this study aims to answer two questions. The first question is: can we combine new observations, vertical land motion estimates, and information on spatial sampling biases to obtain a likely range of 20th-century sea-level rise in the South Atlantic? We combine existing observations with recovered observations from Dakar and a high-resolution sea-level reconstruction based on salt-marsh sediments from the Falkland Islands and find that the rate of sea-level rise in the South Atlantic has likely been between 1.1 and 2.2 mm year−1 (5%–95% confidence intervals), with a central estimate of 1.6 mm year−1. This rate is on the high side, but not statistically different compared to global-mean trends from recent reconstructions. The second question is: are there any physical processes that could explain a large deviation from the global-mean sea-level trend in the South Atlantic? Sterodynamic (changes in ocean dynamics and steric effects) and gravitation, rotation, and deformation effects related to ice mass loss and land water storage have probably led to a 20th-century sea-level trend in the South Atlantic above the global mean. Both observations and physical processes thus suggest that 20th-century sea-level rise in the South Atlantic has been about 0.3 mm year−1 above the rate of global-mean sea-level rise, although even with the additional observations, the uncertainties are still too large to distinguish a statistically significant difference.  
  Programme 688  
  Campaign  
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  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 2169-9291 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8603  
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Author S. Jevrejeva, A. Matthews, A. Slangen doi  isbn
openurl 
  Title The Twentieth-Century Sea Level Budget: Recent Progress and Challenges Type Journal
  Year 2017 Publication Surveys in Geophysics Abbreviated Journal  
  Volume 38 Issue 1 Pages 295-307  
  Keywords (down) Data archeology Observing system Sea level budget Sea level rise  
  Abstract For coastal areas, given the large and growing concentration of population and economic activity, as well as the importance of coastal ecosystems, sea level rise is one of the most damaging aspects of the warming climate. Huge progress in quantifying the cause of sea level rise and closure of sea level budget for the period since the 1990s has been made mainly due to the development of the global observing system for sea level components and total sea levels. We suggest that a large spread (1.2 ± 0.2–1.9 ± 0.3 mm year−1) in estimates of sea level rise during the twentieth century from several reconstructions demonstrates the need for and importance of the rescue of historical observations from tide gauges, with a focus on the beginning of the twentieth century. Understanding the physical mechanisms contributing to sea level rise and controlling the variability of sea level over the past few 100 years are a challenging task. In this study, we provide an overview of the progress in understanding the cause of sea level rise during the twentieth century and highlight the main challenges facing the interdisciplinary sea level community in understanding the complex nature of sea level changes.  
  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 1573-0956 ISBN 1573-0956 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7051  
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Author Chulliat, A.; Blanter, E.; Le Mouël, J.-L.; Shnirman, M. doi  openurl
  Title On the seasonal asymmetry of the diurnal and semidiurnal geomagnetic variations Type Journal Article
  Year 2005 Publication Journal of geophysical research-atmospheres Abbreviated Journal J. Geophys. Res.  
  Volume 110 Issue Pages  
  Keywords (down) daily variation; lower thermospheric winds; ionospheric dynamo; current system; geomagnetic activity; equinoxes; 1555 Geomagnetism and Paleomagnetism: Time variations: diurnal to decadal; 2437 Ionosphere: Ionospheric dynamics; 3369 Atmospheric Processes: Thermospheric dynamics; 3389 Atmospheric Processes: Tides and planetary waves  
  Abstract The diurnal and semidiurnal variations of the geomagnetic field are investigated at 18 observatories using long series of hourly values (up to 97 years at Sitka). The seasonal variations of amplitude of the 12-hour and 24-hour lines are obtained for the H and Z components using a 28-day sliding window. The Fourier analysis is performed using either all days within the window or only the five quietest days. At midlatitudes a strong lack of symmetry about the summer solstice is observed for both lines and both components. This effect is enhanced when selecting quiet days. When averaged over the entire series, the sign of this seasonal asymmetry is the same at 9 out of 10 midlatitude observatories for both lines and for a given component; it is opposite for the H and Z components. Such a coherent seasonal asymmetry is not found at low and high latitudes. At high latitudes a strong annual variation is found inside the polar caps, while a strong semiannual variation is found in the auroral zones. When selecting quiet days, these two effects are weaker, and the seasonal asymmetry becomes comparable to that at midlatitudes. At all latitudes the year-to-year variations of the seasonal asymmetry are uncorrelated with solar activity. It is suggested that lower thermospheric winds may have a similar seasonal asymmetry between spring and autumn equinoxes. Such an asymmetry is present in the published literature but has been overlooked. Possible causes for this wind asymmetry are reviewed.  
  Programme 139  
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  Corporate Author Thesis  
  Publisher American Geophysical Union Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0148-0227 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number IPEV @ Thierry.Lemaire @ Serial 5485  
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Author Alice Gadea, Maryvonne Charrier, Mathieu Fanuel, Philippe Clerc, Corentin Daugan, Aurélie Sauvager, Hélène Rogniaux, Joël Boustie, Anne-Cécile Le Lamer, Françoise Lohézic - Le Devehat file  doi
openurl 
  Title Overcoming deterrent metabolites by gaining essential nutrients: A lichen/snail case study Type Journal
  Year 2019 Publication Phytochemistry Abbreviated Journal  
  Volume 164 Issue Pages 86-93  
  Keywords (down) D-arabitol; Feeding choice; Lichen; Mass spectrometry imaging; Parmeliaceae; Snail; Usnic acid  
  Abstract Specialised metabolites in lichens are generally considered repellent compounds by consumers. Nevertheless, if the only food available is lichens rich in specialised metabolites, lichenophages must implement strategies to overcome the toxicity of these metabolites. Thus, the balance between phagostimulant nutrients and deterrent metabolites could play a key role in feeding preferences. To further understand lichen-gastropod interactions, we studied the feeding behaviour and consumption in Notodiscus hookeri, the land snail native to sub-Antarctic islands. The lichen Usnea taylorii was used because of its simple chemistry, its richness in usnic acid (specialised metabolite) and arabitol (primary metabolite) and its presence in snail habitats. Choice tests in arenas with intact lichens versus acetone-rinsed lichens were carried out to study the influence of specialised metabolites on snail behaviour and feeding preference. Simultaneously, usnic acid and arabitol were quantified and located within the lichen thallus using HPLC-DAD-MS and in situ imaging by mass spectrometry to assess whether their spatial distribution explained preferential snail grazing. No-choice feeding experiments, with the pure metabolites embedded in an artificial diet, defined a gradual gustatory response, from strong repellence (usnic acid) to high appetence (D-arabitol). This case study demonstrates that the nutritional activity of N. hookeri is governed by the chemical quality of the food and primarily by nutrient availability (arabitol), despite the presence of deterrent metabolite (usnic acid).  
  Programme 136  
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  Address  
  Corporate Author Thesis Bachelor's thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9422 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 7652  
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Author Dettai A, Berkani M, Lautredou A-C, Couloux A, Lecointre G, Ozouf-Costaz C, Gallut C, doi  openurl
  Title Tracking the elusive monophyly of nototheniid fishes (Teleostei) with multiple mitochondrial and nuclear markers Type Journal Article
  Year 2012 Publication Marine Genomics Abbreviated Journal  
  Volume 8 Issue Pages 49-58  
  Keywords (down) Cytochrome oxidase 1, Phylogeny, Congruence, Simultaneous analysis,  
  Abstract Since the first molecular study of the suborder Notothenioidei in 1994, many phylogenetic studies have been published. Among these, those with a sufficient number of taxa have all suggested that the Nototheniidae, as currently defined, is monophyletic only with the inclusion of the Channichthyidae, Artedidraconidae, Bathydraconidae and Harpagiferidae. This is corroborated by more recent studies including more taxa, but in these studies either the number of nuclear markers or the number of taxa included remained low. We obtained sequences for a large sampling covering most nototheniid genera for five markers described previously for other samplings (COI, Rhodopsin retrogene, Pkd1, HECW2, and SSRP1) and one nuclear marker never used before in phylogenetic inference (PPM1d). The topology for the combined analysis of the nuclear coding genes, as well as the topology for SSRP1 (non-coding) and the combined analysis for all markers all support the paraphyly of Nototheniidae, the genus Notothenia (including Paranotothenia) is the sister group of the clade Channichthyidae, Artedidraconidae, Bathydraconidae and Harpagiferidae, and genus Gobionotothen is a sister group to both. As in previous studies, Trematomus, Lepidonotothen and Patagonotothen form a clade that also includes Indonotothenia cyanobrancha. The position of Pleuragramma antarctica, Dissostichus species and Aethotaxis mitopteryx remains unstable and dependant on markers and analyses.  
  Programme 1124  
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  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 1874-7787 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 4021  
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Author Pete D. Akers, Joël Savarino, Nicolas Caillon, Aymeric P. M. Servettaz, Emmanuel Le Meur, Olivier Magand, Jean Martins, Cécile Agosta, Peter Crockford, Kanon Kobayashi, Shohei Hattori, Mark Curran, Tas van Ommen, Lenneke Jong, Jason L. Roberts doi  openurl
  Title Sunlight-driven nitrate loss records Antarctic surface mass balance Type Journal
  Year 2022 Publication Nature Communications Abbreviated Journal  
  Volume 13 Issue 1 Pages 4274  
  Keywords (down) Cryospheric science Environmental chemistry Palaeoclimate  
  Abstract Standard proxies for reconstructing surface mass balance (SMB) in Antarctic ice cores are often inaccurate or coarsely resolved when applied to more complicated environments away from dome summits. Here, we propose an alternative SMB proxy based on photolytic fractionation of nitrogen isotopes in nitrate observed at 114 sites throughout East Antarctica. Applying this proxy approach to nitrate in a shallow core drilled at a moderate SMB site (Aurora Basin North), we reconstruct 700 years of SMB changes that agree well with changes estimated from ice core density and upstream surface topography. For the under-sampled transition zones between dome summits and the coast, we show that this proxy can provide past and present SMB values that reflect the immediate local environment and are derived independently from existing techniques.  
  Programme 1177  
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  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 2041-1723 ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 8592  
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Author M. Leduc-Leballeur, G. Picard, G. Macelloni, L. Arnaud, M. Brogioni, A. Mialon, Y. H. Kerr doi  isbn
openurl 
  Title Influence of snow surface properties on L-band brightness temperature at Dome C, Antarctica Type Journal
  Year 2017 Publication Remote Sensing of Environment Abbreviated Journal  
  Volume 199 Issue Pages 427-436  
  Keywords (down) Cryosphere Microwave SMOS Snow emission modeling  
  Abstract L-band radiometer measurements collected over the Dome~C area from 2010 to 2015 indicated that the brightness temperature (TB) was relatively stable at vertical (V) polarization (standard deviation lower than 1K at annual scale), while it was slightly more variable at horizontal (H) polarization. During the 2014–2015 austral summer, an exceptional situation was recorded by both the DOMEX ground radiometer and the European Space Agency (ESA)’s Soil Moisture and Ocean Salinity (SMOS) satellite. From November 2014 to March 2015, TB H showed a progressive and significant increase until 20 March 2015 when it sharply decreased by about 5K (at 52.5° incidence angle) within a few days. In parallel to the increase in TB H, glaciological and meteorological in situ measurements showed a wind speed that was lower than usual and a low-density snow layer being progressively set up on the surface. This was consistent with the exceptional hoar event observed, as well as with snow accumulation on the surface. On the other hand, the decrease in TB H was related to the passing over Dome C of a storm that removed or compacted the layer of light snow on the surface. The WALOMIS (Wave Approach for LOw-frequency MIcrowave emission in Snow) snow-emission model was used with in situ measurements of the snowpack as inputs for evaluating the effect of changes observed on the snow surface in TB H. The simulations indicated that the surface snow density variations were sufficient for predicting the increasing and decreasing trends of the TB H. However, the thickness variations of the superficial layer were essential so as to obtain a better agreement with the SMOS observations. This result confirmed that the L-band TB H was affected by the snow properties of the top centimeters of the snowpack, in spite of the large penetration depth (hundreds of meters). Both the surface snow density and the thickness of the superficial layer were relevant, due to coherent interference effects.  
  Programme 1110  
  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 0034-4257 ISBN 0034-4257 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 6774  
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Author Giovanni Macelloni, Marion Leduc-Leballeur, Francesco Montomoli, Marco Brogioni, Catherine Ritz, Ghislain Picard doi  isbn
openurl 
  Title On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations Type Journal
  Year 2019 Publication Remote Sensing of Environment Abbreviated Journal  
  Volume 233 Issue Pages 111405  
  Keywords (down) Cryosphere L band Snow/ice microwave emission model  
  Abstract Internal temperature is an essential parameter for understanding ice sheet dynamics. Glaciological models provide estimations of temperature profiles over Antarctica and few boreholes are also available, but, at present, no measurement exists at the scale of the whole continent. The analysis of passive L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite shows that, thanks to the high penetration depth (i.e. up to 1500 m), it is possible to infer information on in depth glaciological properties of the ice sheet including temperature. In this study, the temperature profile is retrieved from SMOS observations using jointly glaciological and emission models. The developed methodology is valid in the inner part of Antarctica where the ice sheet is almost stable (i.e. its velocity is limited to 10 m yr−1). This analysis points out that in several cases, differences are observed between retrieved temperature profiles and those predicted by glaciological models. In particular, some geophysical parameters, namely the geothermal heat flux and the mean annual accumulation, need to be modified with respect to their prior values in order to simulate SMOS brightness temperatures. Results also clearly show that the reliability of the retrieved profile in depth decreases with increasing ice thickness due to the limited penetration of microwaves in the ice. The obtained results prove the capability of L band (1.4 GHz) passive microwave sensors for investigating the internal temperature of the ice-sheet.  
  Programme 1110  
  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 0034-4257 ISBN 0034-4257 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 6977  
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Author Gaëlle Lamarque, Jérôme Bascou, Claire Maurice, Jean-Yves Cottin, Nicolas Riel, René-Pierre Ménot doi  isbn
openurl 
  Title Microstructures, deformation mechanisms and seismic properties of a Palaeoproterozoic shear zone: The Mertz shear zone, East-Antarctica Type Journal
  Year 2016 Publication Tectonophysics Abbreviated Journal  
  Volume 680 Issue Pages 174-191  
  Keywords (down) Crustal deformation Crystallographic preferred orientation (CPO) East Antarctica Microstructures Shear zone Strain localization  
  Abstract The Mertz shear zone (MSZ) is a lithospheric scale structure that recorded mid-crustal deformation during the 1.7Ga orogeny. We performed a microstructural and crystallographic preferred orientation (CPO) study of samples from both mylonites and tectonic boudins that constitute relics of the Terre Adélie Craton (TAC). The deformation is highly accommodated in the MSZ by anastomosed shear bands, which become more scattered elsewhere in the TAC. Most of the MSZ amphibolite-facies mylonites display similar CPO, thermal conditions, intensity of deformation and dominant shear strain. Preserved granulite-facies boudins show both coaxial and non-coaxial strains related to the previous 2.45Ga event. This former deformation is more penetrative and less localized and shows a deformation gradient, later affected by a major phase of recrystallization during retrogression at 2.42Ga. Both MSZ samples and granulite-facies tectonic boudins present microstructures that reflect a variety of deformation mechanisms associated with the rock creep that induce contrasted CPO of minerals (quartz, feldspar, biotite, amphibole and orthopyroxene). In particular, we highlight the development of an “uncommon” CPO in orthopyroxene from weakly deformed samples characterized by (010)-planes oriented parallel to the foliation plane, [001]-axes parallel to the stretching lineation and clustering of [100]-axes near the Y structural direction. Lastly, we computed the seismic properties of the amphibolite and granulite facies rocks in the MSZ area in order to evaluate the contribution of the deformed intermediate and lower continental crust to the seismic anisotropy recorded above the MSZ. Our results reveal that (i) the low content of amphibole and biotite in the rock formations of the TAC, and (ii) the interactions between the CPO of the different mineralogical phases, generate a seismically isotropic crust. Thus, the seismic anisotropy recorded by the seismic stations of the TAC, including the MSZ, must be due to mantle rather than crustal structures.  
  Programme 1003  
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  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 0040-1951 ISBN 0040-1951 Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 6748  
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Author Thiebot Jean-Baptiste, Cherel Yves, Acqueberge Manon, Prudor Aurélien, Trathan Philip N, Bost Charles-André, doi  openurl
  Title Adjustment of pre-moult foraging strategies in Macaroni Penguins Eudyptes chrysolophus according to locality, sex and breeding status Type Journal Article
  Year 2014 Publication Ibis Abbreviated Journal Ibis (Lond. 1859)  
  Volume 156 Issue 3 Pages 511-522  
  Keywords (down) Crested Penguins, light-based geolocation, marine habitat, marine resources, non-breeding, Southern Ocean, specialization, stable isotopes,  
  Abstract  
  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 1474-919X ISBN Medium  
  Area Expedition Conference  
  Notes Approved yes  
  Call Number Serial 5116  
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