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Antoine, A. (2022).
Abstract: The sea-ice zone constitutes the breeding and foraging habitat of large populations of ice-based species, pointing at its far-reaching ecological importance. Given its sensitivity to global warming, there is an urgent need for determining how predators use their environment, to understand and predict their response to climate variability. New perspectives are offered by miniature animal-borne sensors: in 2019, 3 sonar tags were deployed on lactating female Weddell seals for 7 days in Terre Adélie to study 3D animal movement and fine-scale predator-prey interactions. Lactating females demonstrated central-place foraging strategy, with restricted foraging area (3-6 km) and mostly benthic dives (97% of dives, visualising the seafloor on echograms). Their foraging effort was constrained by the presence of their pup: females spent most of their time hauling out (77% of overall recordings). The time spent underwater was mostly dedicated to diving (>5m) (1.36 on 7days, 854 dives recorded), as opposed to shallower under ice activities (<5m) (0.3 days). A total of 331 prey capture attempts (PrCA) were recorded, using tri-axial acceleration data, of which 125 prey (4.7 ± 1.5 cm on average) were identified by the sonar on 78 dives (4.24 ± 3.99 PrCA/dive). All PCA occur on the seafloor, at shallower depth than usual Weddell seal records (88 ± 30 m). Lactation is therefore a period of physiological stress, with foraging limited by pup compared with other parts of the life cycle. Using functional principal component analysis and model-based clustering on high resolution dive data, we found that PrCAs occur mostly in 2 of the 5 dive shape clusters. Foraging dives are characterised by W or V shape and high sinuosity, at the scale of the dive (W shapes) or during the ascent phase (V shapes). During the approach phase, seals constantly scan the area by regularly moving their head left to right, suggesting opportunistic behaviour. Shallow phase behaviour was studied using video recordings (2h recorded per seal). Seals spent most of their time interacting with their pup (33%) and hauling-out (42%). Most mother-pup interactions were on sea-ice (71%), as opposed to underwater (29%). The results suggest lactating females’ energy budget changes, with lactation being a period of physiological stress. This period of feeding pressure might put them at higher risk regarding adaptation to environmental variability.
Programme: 1182
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. (2013). An objective rationale for the choice of regularisation parameter with application to global multiple-frequency S-wave tomography
. Solid Earth, 4(2), 357–371.
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Hanna Silvennoinen, Elena Kozlovskaya, Eduard Kissling. (2016). POLENET/LAPNET teleseismic P wave travel time tomography model of the upper mantle beneath northern Fennoscandia (Vol. 7).
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Olga Usoltseva, Elena Kozlovskaya. (2016). Studying local earthquakes in the area Baltic-Bothnia Megashear using the data of the POLENET/LAPNET temporary array (Vol. 7).
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. (2011). (Vol. 2).
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Duprat J. (2017). On the Origin of Interplanetary organics at the surface of icy bodies. Bachelor's thesis, , .
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Fily M., Leroux C., Lenoble J. & Sergent C. (1998). Terrestrial snow studies from remote sensing in the solar spectrum and the thermal infrared. Solar System Ices, , 421–441.
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. (2007). Decametric N Burst: A Consequence of the Interaction of Two Coronal Mass Ejections. Solar physics, 240(2), 301–313.
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Masson, S., Klein, K.-L., Buetikofer, R., Flueckiger, E., Kurt, V., Yushkov B. & Krucker, S. (2009). Acceleration of Relativistic Protons during the 20 January 2005 Flare and CME. SOLAR PHYSICS, 257, 305.
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Klein K-L, Trottet G, Samwel S, Malandraki O, . (2011). Particle Acceleration and Propagation in Strong Flares without Major Solar Energetic Particle Events
. Solar Physics, 269(2), 309–333.
Abstract: Solar energetic particles (SEPs) detected in space are statistically associated with flares and coronal mass ejections (CMEs). But it is not clear how these processes actually contribute to the acceleration and transport of the particles. The present work addresses the question why flares accompanied by intense soft X-ray bursts may not produce SEPs detected by observations with the GOES spacecraft. We consider all X-class X-ray bursts between 1996 and 2006 from the western solar hemisphere. 21 out of 69 have no signature in GOES proton intensities above 10 MeV, despite being significant accelerators of electrons, as shown by their radio emission at cm wavelengths. The majority (11/20) has no type III radio bursts from electron beams escaping towards interplanetary space during the impulsive flare phase. Together with other radio properties, this indicates that the electrons accelerated during the impulsive flare phase remain confined in the low corona. This occurs in flares with and without a CME. Although GOES saw no protons above 10 MeV at geosynchronous orbit, energetic particles were detected in some (4/11) confined events at Lagrangian point L1 aboard ACE or SoHO. These events have, besides the confined microwave emission, dm-m wave type II and type IV bursts indicating an independent accelerator in the corona. Three of them are accompanied by CMEs. We conclude that the principal reason why major solar flares in the western hemisphere are not associated with SEPs is the confinement of particles accelerated in the impulsive phase. A coronal shock wave or the restructuring of the magnetically stressed corona, indicated by the type II and IV bursts, can explain the detection of SEPs when flare-accelerated particles do not reach open magnetic field lines. But the mere presence of these radio signatures, especially of a metric type II burst, is not a sufficient condition for a major SEP event.
Keywords: Physics and Astronomy,
Programme: 227
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