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Gareth Chisham, Angeline G. Burrell, Aurélie Marchaudon, Simon G. Shepherd, Evan G. Thomas, Pasha Ponomarenko. (2021). Comparison of interferometer calibration techniques for improved SuperDARN elevation angles (Vol. 28).
Abstract: The high frequency radars in the Super Dual Auroral Radar Network (SuperDARN) estimate the elevation angles of returned backscatter using interferometric techniques. These elevation angles allow the ground range to the scattering point to be estimated, which is crucial for the accurate geolocation of ionospheric measurements. For elevation angles to be accurately estimated, it is important to calibrate the interferometer measurements by determining the difference in the signal time delays caused by the difference in the electrical path lengths from the main array and the interferometer array to the point at which the signals are correlated. This time delay is known as tdiff. Several methods have been proposed to estimate tdiff using historical observations; these methods are summarised in this paper. Comparisons of the tdiff estimates from the different calibration methods are presented and sources of uncertainty discussed. The effect of errors in the estimated tdiff value on the accuracy of geolocation is evaluated and discussed. The paper concludes with a series of recommendations for both scientific SuperDARN data users and SuperDARN radar operators.
Keywords: Geolocation HF radar Interferometer calibration Ionosphere SuperDARN
Programme: 312
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Simon Thomas, Pierre-Louis Blelly, Aurelie Marchaudon, Julian Eisenbeis, Samuel Bird. (2021). Simulating the Response of the Ionosphere in IPIM to Extreme Space Weather (Vol. 2021).
Abstract: The IRAP Plasmasphere Ionosphere Model (IPIM) is an ionospheric model which describes the transport equations of ionospheric plasma species along magnetic closed field lines. As input, the previous iteration of IPIM used basic models to provide estimations of the solar wind conditions, convection, and precipitation within the ionosphere. In this presentation, we discuss the development of a new operational version of IPIM as part of the EUHFORIA project to monitor and forecast space weather conditions and hazards. The developments of the model include using in-situ solar wind observations from the OMNI data set, ionospheric radar data of plasma motions from the Super Dual Auroral Radar Network (SuperDARN), and precipitation data from the Ovation model, as inputs to the model. A new conductivity module for low latitudes has also been developed for help in the simulation of geomagnetically induced currents. We present the first results from the latest IPIM version which explore the ionosphere's response to different solar wind conditions, before focussing on an extreme coronal mass ejection on 14th July 2012 with clear magnetic cloud and southward magnetic field. For this event, we explore simulations of important plasma properties of the ionosphere and compare with previous model iterations and all available observations and hence describe the skill of using IPIM as a space weather forecasting tool.
Programme: 312
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Juan Pedro Rodríguez-López, Brigitte Van Vliet-Lanoë, Jerónimo López-Martínez, Rebeca Martín-García. (2021). Scouring by rafted ice and cryogenic patterned ground preserved in a Palaeoproterozoic equatorial proglacial lagoon succession, eastern India, Nuna supercontinent (Vol. 123).
Abstract: The Chaibasa Formation contains the oldest known record of ploughmarks formed by rafted ice preserved on Earth. The Palaeoproterozoic (Orosirian-Rhyacian, 1.86–2.1 Ga) Chaibasa Formation in the Dhalbhumgarh area, eastern India, represents sedimentation in an ice-contact proglacial lagoon affected by iceberg (bits and growlers) calving and lake-ice rafting. Ice scouring, both on muddy and sandy substrates, as well as ice “rosettes” developed as consequence of the ploughing action of floating icebergs that were moved by wind, meltwater floods and tidal currents on soft sediments. Muddy flats surrounding the proglacial lagoon underwent seasonal deep freezing conditions developing cryogenic patterned ground containing reticulate ice, ice veins and sand wedges, suggesting the occurrence of proglacial permafrost areas coeval with Proterozoic glaciers. The central part of the proglacial lagoon was characterized by deposition of glacial varves punctuated by pebble and cobble size angular dropstones accumulated in the basin as ice-rafted debris from floating ice. Evidences provided in this paper reinforced the idea that 1.86–2.1 Ga ago glacial conditions prevailed after the supposed ending of the Huronian glaciation. This paper provides detailed examples that can be used to recognize possible floating/drifted ice scours in other Precambrian successions, as these elements have largely passed undetected, being probably widely reported in the literature as generic soft-sediment deformation structures. Similar soft-sediment deformations from Precambrian clastic depositional systems should be re-evaluated as there is a significant possibility that most of the Precambrian iceberg-related structures had escape notice, as originally suggested Eyles et al. in 1997.
Keywords: Ice-rafted debris Iceberg scouring India Palaeoproterozoic Permafrost Proglacial Reticulate ice
Programme: 316
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Amalie Vigdel Ask, Bjørn Munro Jenssen, Sabrina Tartu, Frédéric Angelier, Olivier Chastel, Geir Wing Gabrielsen. (2021). Per- and Polyfluoroalkyl Substances Are Positively Associated with Thyroid Hormones in an Arctic Seabird (Vol. 40).
Abstract: Per- and polyfluoroalkyl substances (PFAS) are associated with several disrupted physiological and endocrine parameters. Regarding endocrine mechanisms, laboratory studies suggest that PFAS could disrupt the thyroid hormone system and alter circulating thyroid hormone concentrations. Thyroid hormones play a ubiquitous role—controlling thermoregulation, metabolism, and reproduction. However, evidence for disruption of thyroid hormones by PFAS remains scarce in wildlife. The present study investigated the associations between concentrations of PFAS, thyroid hormones, and body condition in an arctic seabird, the black-legged kittiwake (Rissa tridactyla). We collected blood from kittiwakes sampled in Svalbard, Norway (2013 and 2014). Plasma samples were analyzed for total thyroxine (TT4) and total triiodothyronine (TT3) concentrations; detected PFAS included branched and linear (lin) C8 perfluoroalkyl sulfonates (i.e., perfluoroctane sulfonate [PFOS]) and C9-C14 perfluoroalkyl carboxylates (PFCAs). The dominant PFAS in the kittiwakes were linPFOS and C11- and C13-PFCAs. Generally, male kittiwakes had higher concentrations of PFAS than females. We observed positive correlations between linPFOS, C10-PFCA, and TT4 in males, whereas in females C12-14-PFCAs were positively correlated to TT3. Interestingly, we observed contrasted correlations between PFAS and body condition; the direction of the relationship was sex-dependent. Although these results show relationships between PFAS and circulating thyroid hormone concentrations in kittiwakes, the study design does not allow for concluding on causal relationships related to effects of PFAS on the thyroid hormone system. Future experimental research is required to quantify this impact of PFAS on the biology of kittiwakes. The apparently different associations among PFAS and body condition for males and females are puzzling, and more research is required. Environ Toxicol Chem 2021;40:820–831. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Keywords: Avian toxicity Ecotoxicology Endocrine-disrupting compounds Per- and polyfluoroalkyl substance Thyroid hormones
Programme: 330
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Dj Léandri-Breton, A Tarroux, K Elliott, P Legagneux, F Angelier, P Blévin, Vs Bråthen, P Fauchald, A Goutte, W Jouanneau, S Tartu, B Moe, O Chastel. (2021). Long-term tracking of an Arctic-breeding seabird indicates high fidelity for pelagic wintering areas.
Abstract: Site fidelity is driven by predictable resource distributions in time and space. However, intrinsic factors related to an individual’s physiology and life-history traits can contribute to consistent foraging behaviour and movement patterns. Using 11 years of continuous geolocation tracking data (fall 2008 to spring 2019), we investigated spatiotemporal consistency in non-breeding movements in a pelagic seabird population of black-legged kittiwakes (Rissa tridactyla) breeding in the High Arctic (Svalbard). Our objective was to assess the relative importance of spatial versus temporal repeatability behind inter-annual movement consistency during winter. Most kittiwakes used pelagic regions of the western North Atlantic. Winter site fidelity was high both within and across individuals and at meso (100-1000 km) and macro scales (>1000 km). Spatial consistency in non-breeding movement was higher within than among individuals, suggesting that site fidelity might emerge from individuals’ memory to return to locations with predictable resource availability. Consistency was also stronger in space than in time, suggesting that it was driven by consistent resource pulses that may vary in time more so than in space. Nonetheless, some individuals displayed more flexibility by adopting a strategy of itinerancy during winter, and the causes of this flexibility are unclear. Specialization for key wintering areas can indicate vulnerability to environmental perturbations, with winter survival and carry-over effects arising from winter conditions as potential drivers of population dynamics
Programme: 330
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Philip Bertrand, Joël Bêty, Nigel G. Yoccoz, Marie-Josée Fortin, Hallvard Strøm, Harald Steen, Jack Kohler, Stephanie M. Harris, Samantha C. Patrick, Olivier Chastel, P. Blévin, Haakon Hop, Geir Moholdt, Joséphine Maton, Sébastien Descamps. (2021). Fine-scale spatial segregation in a pelagic seabird driven by differential use of tidewater glacier fronts (Vol. 11).
Abstract: In colonially breeding marine predators, individual movements and colonial segregation are influenced by seascape characteristics. Tidewater glacier fronts are important features of the Arctic seascape and are often described as foraging hotspots. Albeit their documented importance for wildlife, little is known about their structuring effect on Arctic predator movements and space use. In this study, we tested the hypothesis that tidewater glacier fronts can influence marine bird foraging patterns and drive spatial segregation among adjacent colonies. We analysed movements of black-legged kittiwakes (Rissa tridactyla) in a glacial fjord by tracking breeding individuals from five colonies. Although breeding kittiwakes were observed to travel up to ca. 280 km from the colony, individuals were more likely to use glacier fronts located closer to their colony and rarely used glacier fronts located farther away than 18 km. Such variation in the use of glacier fronts created fine-scale spatial segregation among the four closest (ca. 7 km distance on average) kittiwake colonies. Overall, our results support the hypothesis that spatially predictable foraging patches like glacier fronts can have strong structuring effects on predator movements and can modulate the magnitude of intercolonial spatial segregation in central-place foragers.
Keywords: Behavioural ecology Biogeography
Programme: 330
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William Jouanneau, Don-Jean Léandri-Breton, Alexandre Corbeau, Dorte Herzke, Børge Moe, Vladimir A. Nikiforov, Geir W. Gabrielsen, Olivier Chastel. (2021). A Bad Start in Life? Maternal Transfer of Legacy and Emerging Poly- and Perfluoroalkyl Substances to Eggs in an Arctic Seabird (Vol. 56).
Abstract: In birds, maternal transfer is a major exposure route for several contaminants, including poly- and perfluoroalkyl substances (PFAS). Little is known, however, about the extent of the transfer of the different PFAS compounds to the eggs, especially for alternative fluorinated compounds. In the present study, we measured legacy and emerging PFAS, including Gen-X, ADONA, and F-53B, in the plasma of prelaying black-legged kittiwake females breeding in Svalbard and the yolk of their eggs. We aimed to (1) describe the contaminant levels and patterns in both females and eggs, and (2) investigate the maternal transfer, that is, biological variables and the relationship between the females and their eggs for each compound. Contamination of both females and eggs were dominated by linPFOS then PFUnA or PFTriA. We notably found 7:3 fluorotelomer carboxylic acid─a precursor of long-chain carboxylates─in 84% of the egg yolks, and provide the first documented finding of ADONA in wildlife. Emerging compounds were all below the detection limit in female plasma. There was a linear association between females and eggs for most of the PFAS. Analyses of maternal transfer ratios in females and eggs suggest that the transfer is increasing with PFAS carbon chain length, therefore the longest chain perfluoroalkyl carboxylic acids (PFCAs) were preferentially transferred to the eggs. The mean ∑PFAS in the second-laid eggs was 73% of that in the first-laid eggs. Additional effort on assessing the outcome of maternal transfers on avian development physiology is essential, especially for PFCAs and emerging fluorinated compounds which are under-represented in experimental studies.
Programme: 330
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Chastel O., Blévin P., Humann‑Guilleminot S., Helfenstein F., Tartu S., Angelier F., Sebastiano M., Costantini D., Shaffer S., Bustamante P., Labadie P., Budzinski H., Herzke D., Moe B., Bustnes J.O., Gabrielsen G.W. . (2021). Contaminants of growing concern: Poly- and Perfluoroalkylated Substances (PFAS) and their physiological consequences in seabirds.
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Per Fauchald, Arnaud Tarroux, Françoise Amélineau, Vegard Sandøy Bråthen, Sébastien Descamps, Morten Ekker, Halfdan Helgi Helgason, Malin Kjellstadli Johansen, Benjamin Merkel, Børge Moe, Jens Åström, Tycho Anker-Nilssen, Oskar Bjørnstad, Olivier Chastel, Signe Christensen-Dalsgaard, Jóhannis Danielsen, Francis Daunt, Nina Dehnhard, Kjell Einar Erikstad, Alexey Ezhov, Maria Gavrilo, Gunnar Thor Hallgrimsson, Erpur Snær Hansen, Mike Harris, Morten Helberg, Jón Einar Jónsson, Yann Kolbeinsson, Yuri Krasnov, Magdalene Langset, Svein-Håkon Lorentsen, Erlend Lorentzen, Mark Newell, Bergur Olsen, Tone Kristin Reiertsen, Geir Helge Systad, Paul Thompson, Thorkell Lindberg Thórarinsson, Sarah Wanless, Katarzyna Wojczulanis-Jakubas, Hallvard Strøm. (2021). Year-round distribution of Northeast Atlantic seabird populations: applications for population management and marine spatial planning (Vol. 676).
Abstract: Tracking data of marine predators are increasingly used in marine spatial management. We developed a spatial data set with estimates of the monthly distribution of 6 pelagic seabird species breeding in the Northeast Atlantic. The data set was based on year-round global location sensor (GLS) tracking data of 2356 adult seabirds from 2006-2019 from a network of seabird colonies, data describing the physical environment and data on seabird population sizes. Tracking and environmental data were combined in monthly species distribution models (SDMs). Cross-validations were used to assess the transferability of models between years and breeding locations. The analyses showed that birds from colonies close to each other (<500 km apart) used the same nonbreeding habitats, while birds from distant colonies (>1000 km) used colony-specific and, in many cases, non-overlapping habitats. Based on these results, the SDM from the nearest model colony was used to predict the distribution of all seabird colonies lying within a species-specific cut-off distance (400-500 km). Uncertainties in the predictions were estimated by cluster bootstrap sampling. The resulting data set consisted of 4692 map layers, each layer predicting the densities of birds from a given species, colony and month across the North Atlantic. This data set represents the annual distribution of 23.5 million adult pelagic seabirds, or 87% of the Northeast Atlantic breeding population of the study species. We show how the data set can be used in population and spatial management applications, including the detection of population-specific nonbreeding habitats and identifying populations influenced by marine protected areas.
Keywords: Alle alle Fratercula arctica Fulmarus glacialis Marine spatial planning Rissa tridactyla SEATRACK Uria aalge Uria lomvia
Programme: 330
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F. Amélineau, B. Merkel, A. Tarroux, S. Descamps, T. Anker-Nilssen, O. Bjørnstad, V. S. Bråthen, O. Chastel, S. Christensen-Dalsgaard, J. Danielsen, F. Daunt, N. Dehnhard, M. Ekker, K. E. Erikstad, A. Ezhov, P. Fauchald, M. Gavrilo, G. T. Hallgrimsson, E. S. Hansen, M. P. Harris, M. Helberg, H. H. Helgason, M. K. Johansen, J. E. Jónsson, Y. Kolbeinsson, Y. Krasnov, M. Langset, S. H. Lorentsen, E. Lorentzen, M. V. Melnikov, B. Moe, M. A. Newell, B. Olsen, T. Reiertsen, G. H. Systad, P. Thompson, T. L. Thórarinsson, E. Tolmacheva, S. Wanless, K. Wojczulanis-Jakubas, J. Åström, H. Strøm. (2021). Six pelagic seabird species of the North Atlantic engage in a fly-and-forage strategy during their migratory movements (Vol. 676).
Abstract: Bird migration is commonly defined as a seasonal movement between breeding and non-breeding grounds. It generally involves relatively straight and directed large-scale movements, with a latitudinal change, and specific daily activity patterns comprising less or no foraging and more traveling time. Our main objective was to describe how this general definition applies to seabirds. We investigated migration characteristics of 6 pelagic seabird species (little auk Alle alle, Atlantic puffin Fratercula arctica, common guillemot Uria aalge, Brünnich’s guillemot U. lomvia, black-legged kittiwake Rissa tridactyla and northern fulmars Fulmarus glacialis). We analysed an extensive geolocator positional and saltwater immersion dataset from 29 colonies in the North-East Atlantic and across several years (2008-2019). We used a novel method to identify active migration periods based on segmentation of time series of track characteristics (latitude, longitude, net-squared displacement). Additionally, we used the saltwater immersion data of geolocators to infer bird activity. We found that the 6 species had, on average, 3 to 4 migration periods and 2 to 3 distinct stationary areas during the non-breeding season. On average, seabirds spent the winter at lower latitudes than their breeding colonies and followed specific migration routes rather than non-directionally dispersing from their colonies. Differences in daily activity patterns were small between migratory and stationary periods, suggesting that all species continued to forage and rest while migrating, engaging in a ‘fly-and-forage’ migratory strategy. We thereby demonstrate the importance of habitats visited during seabird migrations as those that are not just flown over, but which may be important for re-fuelling.
Keywords: Common murres Dovekies Light-level geolocation Migration strategies Non-breeding movements Thick-billed murres
Programme: 330
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