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Alexandra Lavrillier, Semen Gabyshev, Liudmila Egorova, Galina Makarova, Maia Lomovtseva-Adukanova. (2021). Analysing Non-Existent and Existing Tourisms in Eastern Siberia among the Evenki, Even, Koryak and Itelmen.
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Steven Franke, Daniela Jansen, Sebastian Beyer, Niklas Neckel, Tobias Binder, John Paden, Olaf Eisen. (2021). Complex Basal Conditions and Their Influence on Ice Flow at the Onset of the Northeast Greenland Ice Stream (Vol. 126).
Abstract: Abstract The ice stream geometry and large ice surface velocities at the onset region of the Northeast Greenland Ice Stream (NEGIS) are not yet well reproduced by ice sheet models. The quantification of basal sliding and a parametrization of basal conditions remains a major gap. In this study, we assess the basal conditions of the onset region of the NEGIS in a systematic analysis of airborne ultra-wideband radar data. We evaluate basal roughness and basal return echoes in the context of the current ice stream geometry and ice surface velocity. We observe a change from a smooth to a rougher bed where the ice stream widens, and a distinct roughness anisotropy, indicating a preferred orientation of subglacial structures. In the upstream region, the excess ice mass flux through the shear margins is evacuated by ice flow acceleration and along-flow stretching of the ice. At the downstream part, the generally rougher bed topography correlates with a decrease in flow acceleration and lateral variations in ice surface velocity. Together with basal water routing pathways, this hints to two different zones in this part of the NEGIS: the upstream region collecting water, with a reduced basal traction, and downstream, where the ice stream is slowing down and is widening on a rougher bed, with a distribution of basal water toward the shear margins. Our findings support the hypothesis that the NEGIS is strongly interconnected to the subglacial water system in its onset region, but also to the subglacial substrate and morphology.
Keywords: basal roughness bed conditions Greenland Ice Sheet ice stream Northeast Greenland Ice Stream radio-echo sounding
Programme: 1180
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. (2021). Behavioural responses of breeding arctic sandpipers to ground-surface temperature and primary productivity (Vol. 755).
Abstract: Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success.
Keywords: Environmental conditions Incubation behaviour Incubation recesses Incubation strategy Lag effects NDVI Shorebird
Programme: 1036
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Van Hanja J. (2021).
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Meudec L. (2021).
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Morgan Godard. (2021).
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Karl-Ludwig Klein. (2021). Radio Astronomical Tools for the Study of Solar Energetic Particles II.Time-Extended Acceleration at Subrelativistic and Relativistic Energies (Vol. 7).
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Morten Frederiksen, Olivier Gilg, Glenn Yannic. (2021). Cross-icecap spring migration confirmed in a high-Arctic seabird, the Ivory Gull Pagophila eburnea (Vol. 163).
Keywords: ecological barrier Greenland icecap high-altitude migration
Programme: 1210
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. (2021). Scouring by rafted ice and cryogenic patterned ground preserved in a Palaeoproterozoic equatorial proglacial lagoon succession, eastern India, Nuna supercontinent (Vol. 123).
Keywords: Ice-rafted debris Iceberg scouring India Palaeoproterozoic Permafrost Proglacial Reticulate ice
Programme: 316
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. (2021). Predation by feral cats threatens great albatrosses (Vol. 23).
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