| |
Records |
Links |
|
Author |
G. Hubert, S. Aubry |
|
| |
Title |
Simulation of atmospheric cosmic-rays and their impacts based on pre-calculated databases, physical models and computational methods |
Type |
Journal |
| |
Year  |
2021 |
Publication |
Journal of Computational Science |
Abbreviated Journal |
|
|
| |
Volume |
51 |
Issue |
|
Pages |
101307 |
|
| |
Keywords |
Ambient dose equivalent Atmospheric cosmic-rays Cosmogenic nuclide production Multi-physics Single event effect |
|
| |
Abstract |
The atmospheric cosmic-ray environment is composed of secondary particles produced when primary cosmic rays interact with the nucleus of atmospheric atoms. Modeling of atmospheric radiations is essential for investigating their impacts on human activities such as radiation risks in aviation or scientific fields such as cosmogenic dating. The nuclear transport codes are a common and accurate way to model the cosmic ray interaction in the atmosphere with minimal approximations. However, tracking all produced secondary particles in each event in the whole depth of the atmosphere and sampling many events to obtain the statistically meaningful results would be a computational challenge and disadvantageous from the point of view of time consumption. This paper presents a computational platform names ATMOS CORE based on pre-calculated databases coupled to physical models and computational methods. The fields of application concern the atmospheric cosmic-rays characterization as well as their effects on electronics systems, on the ambient dose for aircrews or the cosmogenic nuclide production for dating activities. Some comparisons between simulations and measurements are also presented and discussed. |
|
| |
Programme |
1112 |
|
| |
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 |
1877-7503 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7957 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
G. Hubert, S. Aubry |
|
| |
Title |
Study of the Impact of Past Extreme Solar Events on the Modern Air Traffic |
Type |
Journal |
| |
Year |
2021 |
Publication |
Space Weather |
Abbreviated Journal |
|
|
| |
Volume |
19 |
Issue |
4 |
Pages |
e2020SW002665 |
|
| |
Keywords |
|
|
| |
Abstract |
The ancient solar energetic particle (SEP) events of 774/775 CE and 993/994 CE were characterized thanks to radionuclide productions stored in environmental archives as ice cores or tree rings. Primary cosmic ray spectra deduced from these cosmogenic isotope data indicate that the impact of these extreme SEP events would have been much more significant than any of the ones observed during the modern era. However, the impact of these should be studied more accurately in the framework of the ambient dose equivalent impacting aircrew and passengers in the air traffic context by considering physical parameters such as time profile or anisotropy properties. In this study, the impact that 774/775 CE and 993/994 CE past extreme SEP events could have had on modern air traffic is discussed. Possible event spectra for these ancient events are derived from the spectra ground-level enhancement (GLE) 5 and GLE 69, which have been observed during the modern era and have been widely studied/characterized using measurements. The investigations include the impact of the SEP activity on ambient dose equivalent, including detailed analyses considering route, airplane characteristics (departure, arrival, continent, airplane type), and the time occurrence of the SEP event. Statistical analyses show that additional dose levels can reach values on the order of 70 mSv, which is absolutely significant considering the current air traffic recommendations. The orders of magnitude of the ambient dose equivalent induced during past extreme SEP events raises a number of issues, both for aircrews and for avionics hardware. This study demonstrates that simulations can be useful for the evaluation of risks in case of extreme SEP events. |
|
| |
Programme |
1112 |
|
| |
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 |
1542-7390 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
7934 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
G. J. Sutton, C. A. Bost, A. Z. Kouzani, S. D. Adams, K. Mitchell, J. P. Y. Arnould |
|
| |
Title |
Fine-scale foraging effort and efficiency of Macaroni penguins is influenced by prey type, patch density and temporal dynamics |
Type |
Journal |
| |
Year |
2021 |
Publication |
Marine Biology |
Abbreviated Journal |
|
|
| |
Volume |
168 |
Issue |
1 |
Pages |
3 |
|
| |
Keywords |
|
|
| |
Abstract |
Difficulties quantifying in situ prey patch quality have limited our understanding of how marine predators respond to variation within and between patches, and throughout their foraging range. In the present study, animal-borne video, GPS, accelerometer and dive behaviour data loggers were used to investigate the fine-scale foraging behaviour of Macaroni penguins (Eudyptes chrysolophus) in response to prey type, patch density and temporal variation in diving behaviour. Individuals mainly dived during the day and utilised two strategies, targeting different prey types. Subantarctic krill (Euphausia vallentini) were consumed during deep dives, while small soft-bodied fish were captured on shallow dives or during the ascent phase of deep dives. Despite breeding in large colonies individuals seemed to be solitary foragers and did not engage with conspecifics in coordinated behaviour as seen in other group foraging penguin species. This potentially reflects the high abundance and low manoeuvrability of krill. Video data were used to validate prey capture signals in accelerometer data and a Support Vector Machine learning algorithm was developed to identify prey captures that occurred throughout the entire foraging trip. Prey capture rates indicated that Macaroni penguins continued to forage beyond the optimal give up time. However, bout-scale analysis revealed individuals terminated diving behaviour for reasons other than patch quality. These findings indicate that individuals make complex foraging decisions in relation to their proximate environment over multiple spatio-temporal scales. |
|
| |
Programme |
394 |
|
| |
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 |
1432-1793 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
2037 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Garcin N, Viblanc VA, Schull Q, Michaux D, Reichert S, Robin JP, Bize P, Stier A |
|
| |
Title |
Naturally equipped to resist stress |
Type |
Peer-reviewed symposium |
| |
Year |
2021 |
Publication |
Society for experimental biology annual conference. poster. actes du colloque |
Abbreviated Journal |
|
|
| |
Volume |
|
Issue |
|
Pages |
|
|
| |
Keywords |
|
|
| |
Abstract |
Stress exposure and stress response are likely to vary according to life history strategies and environmental contexts. Although the acute release of glucocorticoids in response to unpredictable environmental conditions may lead to adaptative behavioral and physiological responses, exposure to high glucocorticoid levels on the long-term usually leads to deleterious cascading effects on animal’s physiology, behavior and fitness. Yet, some species may be more adapted to cope with challenging events than others and might naturally possess protective mechanisms limiting the adverse consequences of prolonged exposure to high glucocorticoid levels. King penguin chicks being naturally exposed to harsh weather, prolonged fasting and constant predation pressure, we investigated the life-history, behavioral and physiological consequences of an experimental increase in corticosterone levels on the medium and long-term (after removing implants), predicting to find relatively few costs associated with such treatment. Although non-significant, CORT-treated chicks were slightly larger, fledged slightly earlier and had slightly higher survival chances than placebo chicks. CORT-treated chicks were significantly more aggressive and displayed lower corticosterone response to acute stress on the medium term, while their physical activity and whole-body energetics were not significantly affected. While mitochondrial density was not significantly affected by the CORT treatment, CORT-treated chicks had lower oxidative stress levels on the long-term than placebo ones, and no significant impact was observed on telomere shortening. Finally, the expression of several genes (i.e. CORT receptor, HSP90, mTOR, NRF2 and TERF2) was up regulated in treated chicks, which could potentially mediate the apparent ‘stress’ resistance we observed at the phenotypic level. |
|
| |
Programme |
119 |
|
| |
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 |
8454 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gareth Chisham, Angeline G. Burrell, Aurélie Marchaudon, Simon G. Shepherd, Evan G. Thomas, Pasha Ponomarenko |
|
| |
Title |
Comparison of interferometer calibration techniques for improved SuperDARN elevation angles |
Type |
Journal |
| |
Year |
2021 |
Publication |
Polar Science |
Abbreviated Journal |
|
|
| |
Volume |
28 |
Issue |
|
Pages |
100638 |
|
| |
Keywords |
Geolocation HF radar Interferometer calibration Ionosphere SuperDARN |
|
| |
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. |
|
| |
Programme |
312 |
|
| |
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 |
1873-9652 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8088 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Gómez Coutouly, Yan Axel |
|
| |
Title |
Un peuplement antérieur à 20 000 ans en Amérique ? Le caractère anthropique des sites de Pedra Furada (Brésil) en question |
Type |
Journal |
| |
Year |
2021 |
Publication |
Bulletin de la société préhistorique française |
Abbreviated Journal |
|
|
| |
Volume |
118 |
Issue |
2 |
Pages |
245-275 |
|
| |
Keywords |
|
|
| |
Abstract |
|
|
| |
Programme |
1217 |
|
| |
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 |
8690 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Grégoire Mureau |
|
| |
Title |
Étude des impacts des événements extrêmes sur le massif dunaire de la plage de Sanvík (Islande) |
Type |
Master 1 |
| |
Year |
2021 |
Publication |
Université de bretagne occidentale |
Abbreviated Journal |
|
|
| |
Volume |
https://www-iuem.univ-brest.fr/pops/attachments/26 |
Issue |
|
Pages |
62 p. |
|
| |
Keywords |
|
|
| |
Abstract |
|
|
| |
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 |
8383 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Grémillet, David |
|
| |
Title |
Les manchots de Mandela et autres récits océaniques |
Type |
Book |
| |
Year |
2021 |
Publication |
|
Abbreviated Journal |
|
|
| |
Volume |
|
Issue |
|
Pages |
232 pages |
|
| |
Keywords |
|
|
| |
Abstract |
|
|
| |
Programme |
388 |
|
| |
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 |
978-2-330-15652-7 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
8448 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Guillaume Bridier, Frédéric Olivier, Laurent Chauvaud, Mikael K. Sejr, Jacques Grall |
|
| |
Title |
Food source diversity, trophic plasticity, and omnivory enhance the stability of a shallow benthic food web from a high-Arctic fjord exposed to freshwater inputs |
Type |
Journal |
| |
Year |
2021 |
Publication |
Limnology and Oceanography |
Abbreviated Journal |
|
|
| |
Volume |
66 |
Issue |
S1 |
Pages |
S259-S272 |
|
| |
Keywords |
|
|
| |
Abstract |
Under climate change, many Arctic coastal ecosystems receive increasing amounts of freshwater, with ecological consequences that remain poorly understood. In this study, we investigated how freshwater inputs may affect the small-scale structure of benthic food webs in a low-production high-Arctic fjord (Young Sound, NE Greenland). We seasonally sampled benthic invertebrates from two stations receiving contrasting freshwater inputs: an inner station exposed to turbid and nutrient-depleted freshwater flows and an outer station exposed to lower terrestrial influences. Benthic food web structure was described using a stable isotope approach (δ13C and δ15N), Bayesian models, and community-wide metrics. The results revealed the spatially and temporally homogeneous structure of the benthic food web, characterized by high trophic diversity (i.e., a wide community isotopic niche). Such temporal stability and spatial homogeneity mirrors the high degree of trophic plasticity and omnivory of benthic consumers that allows the maintenance of several carbon pathways through the food web despite different food availability. Furthermore, potential large inputs of shelf organic matter together with local benthic primary production (i.e., macroalgae and presumably microphytobenthos) may considerably increase the stability of the benthic food web by providing alternative food sources to locally runoff-impacted pelagic primary production. Future studies should assess beyond which threshold limit a larger increase in freshwater inputs might cancel out these stability factors and lead to marked changes in Arctic benthic ecosystems. |
|
| |
Programme |
1158 |
|
| |
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 |
1939-5590 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
yes |
|
| |
Call Number |
|
Serial |
6791 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Guillaume Hubert |
|
| |
Title |
Analyses of the Secondary Cosmic Ray using CCD camera in high-altitude observatories and Antarctica stations |
Type |
Peer-reviewed symposium |
| |
Year |
2021 |
Publication |
|
Abbreviated Journal |
|
|
| |
Volume |
395 |
Issue |
|
Pages |
1238 |
|
| |
Keywords |
Array Pixel Sensors (APS) Charge-Coupled Device (CCD) |
|
| |
Abstract |
Charge-Coupled Device (CCD) and Array Pixel Sensors (APS) can be used to image radiation-induced energy deposition. The high sensitivity of depleted silicon to ionizing radiation constitutes an opportunity to investigate radiation effects while it is a nuisance to astronomer activities. CCD and APS provide a better combination of spatial and intensity resolution for radiation events than other available types of detector. This paper proposes to analyze radiation events observed in the CCD camera and more specifically analyses of charge deposition spectra and spatially extensive events. Measurements were performed in the Pic du Midi from 2011 to 2015 and in the Concordia Antarctica station since 2018. Coupled transport models (i.e. particle transport and charge transport in semiconductors) allow investigating contributions to charge collection spectra as a function of the particle nature, i.e. neutron, proton and muon. Coupled measurements and simulations allow to access to the detected secondary CR flux and the charge deposition pattern. Results showed that high charge level events seen on atmospheric sites can be considered as hadronic component (mainly neutrons and protons) while low charge levels and punctual events are induced by muons which are able to generate up to 3 fC in the CCD camera. Hence, thanks to double level of measurement sites, muon discrimination from other secondary particles has been investigated. Cross-comparison analyses based on CCD and neutron spectrometers operated in both station/observatory investigate secondary CR dynamic. |
|
| |
Programme |
1112 |
|
| |
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 |
8325 |
|
| Permanent link to this record |
