Michael Lockwood, Mathew J. Owens, Carl Haines, Luke Barnard, Christopher John Scott, Aude Chambodut, Kathryn A. McWilliams, Alan W. P. Thomson. (2020). Universal Time Variations in Space Weather (Vol. 12).
Abstract: We introduce the inductive effects of polar cap motions towards and way from the Sun into magnetospheric electrodynamics and show how this explains observed Universal Time variations in hemispheric geomagnetic indices. The large (and growing) hemispheric asymmetry in the offsets of the geomagnetic (dip or eccentric dipole) poles from Earth’s rotational axis means that the effect is not cancelled out in global indices. By adding this effect to that of the Russell-McPherron effect on solar wind-magnetosphere coupling, that of ionospheric conductivities, and that of the solar wind dynamic pressure and dipole tilt on the near-Earth tail lobe field and cross-tail current sheet, we are able to model the persistent “equinoctial” time-of-day/time-of-year pattern (with additional net Universal time variations) observed in the an, as and am geomagnetic indices since 1959. We discuss the implications for the longitudinal dependence of the effects of extreme space weather events
Programme: 139
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A. Wargnier. (2020). Characterising the time profiles of relativistic solar energetic particle events observed by neutron monitors.
Abstract: This Report Presents The Result Of The Measurement Of Characteristic Times For Relativistic Solar Energetic Par- Ticle Events Observed By Neutron Monitors. The Typical Profile Of A Solar Event Observed By Neutrons Monitors Is A Fast Rise And A Slow Decay. But These Times Differ Between Events (From A Few Minutes To Several Hours) And Quantifying Them Is Interesting. In Fact, Studying These Characteristic Times Allows Us To Better Understand Solar High Energy Events. For This, We Used The Neutron Monitor Database (Nmdb) [1] And Python To Compute The Rise Time And The Decay Time. We Observed That There Is A Linear Relationship Between Rise Time And Decay Time Of These Solar Events.there Are Some Possible Interpretations For These Characteristic Times. These Times May Be Related To The Dura- Tion Of Particle Acceleration Or The Propagation Of The Particles In The Interplanetary Medium. We Looked Then For A Link Between The Measurement Of Neutron Monitors At The Earth And The Solar Activity: In X-rays, And The Microwave Domain. Furthermore, We Studied The Fluctuations Of The Interplanetary Magnetic Field. However, All These Attempts Were Unsuccessful To Find A Relation With The Rise Time Measured By Neutron Monitors. But Ejection Speeds Of Coronal Mass Ejections And Rise Time Solar Events Detected By Neutron Monitors May Be Linked.
Programme: 227
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Adam T. Devlin, Jiayi Pan, Hui Lin. (2020). Multi-Timescale Analysis of Tidal Variability in the Indian Ocean Using Ensemble Empirical Mode Decomposition (Vol. 125).
Abstract: Ocean tides have been observed to be changing worldwide for nonastronomical reasons, which can combine with rising mean sea level (MSL) to increase the long-term impact to coastal regions. Tides can also exhibit variability at shorter timescales, which may be correlated with short-term variability in MSL. This short-term coupling may yield higher peak water levels and increased impacts of exceedance events that may be equally significant as long-term sea level rise. Previous studies employed the tidal anomaly correlation (TAC) method to quantify the sensitivity of tides to MSL fluctuations at long-period (>20 years) tide gauges in basin-scale surveys of the Pacific and Atlantic Ocean, finding that TACs exist at most locations. The Indian Ocean also experiences significant sea level rise and tidal variability yet has been less studied due to a sparse network of tide gauges. However, since the beginning of the 21st century, more tide gauges have been established in a wider geographical range, bringing the possibility of better estimates of tidal and MSL variability. Here, we improve the TAC approach, using the ensemble empirical mode decomposition (EEMD) method to analyze tidal amplitudes and sea level at multiple frequency bands, allowing a more effective use of shorter record tide gauges and better understanding of multiple timescales of tidal variability. We apply this approach to 73 tide gauges in the Indian Ocean to better quantify tidal variability in these under-studied regions, finding that the majority of locations exhibit significant correlations of tides and MSL.
Keywords: Coastal risks Ensemble Empirical Mode Decomposition Indian Ocean Sea level variability Tidal evolution Tidal variability
Programme: 688
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Adriane Cristina Mendes Prado, Mauricio Tizziani Pazianotto, Jose Manuel Quesada Molina, Miguel Antonio Cortes-Giraldo, Guillaume Hubert, Marlon Antonio Pereira, Claudio Antonio Federico. (2020). Simulation of Cosmic Radiation Transport Inside Aircraft for Safety Applications (Vol. 56).
Abstract: During the flight, an aircraft is submitted to a radiation environment composed of cosmic-ray-induced particles (CRIP) of which neutrons are responsible for approximately 40% of the crew effective dose and are the main cause of single event effects (SEE) in avionics systems at flight altitudes. A model of Learjet aircraft was developed on Monte Carlo simulation using the MCNPX code in order to detail the CRIP field inside the aircraft. The radiation source modeling was previously developed by a computational platform that simulates the energy and angular distributions of the CRIP along the atmosphere. In this article, we determined the variation of the neutron radiation field in several positions inside the aircraft at 11- and 18-km altitudes and for both equatorial and polar regions. The results suggest that the maximum variation of neutron fluence rate between different positions inside the aircraft shows a tendency of higher differences for a lower energy threshold (thermal and E > 1 MeV) in comparison with those differences for a higher energy threshold (E > 10 MeV). Moreover, the angular distribution results show relevant differences between positions inside aircraft, mainly for thermal neutrons close to the fuel. The general tendency is to enhance these discrepancies for devices with new technologies, due to their lower energy threshold for SEE occurrences.
Keywords: Aerospace electronics Aircraft Aircraft manufacture Aircraft simulation Atmospheric modeling Computational modeling cosmic radiation neutron fluence rate Neutrons safety single event effect
Programme: 1112
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Agnès Lewden, Andreas Nord, Batshéva Bonnet, Florent Chauvet, André Ancel, Dominic J. McCafferty. (2020). Body surface rewarming in fully and partially hypothermic king penguins (Vol. 190).
Abstract: Penguins face a major thermal transition when returning to land in a hypothermic state after a foraging trip. Uninsulated appendages (flippers and feet) could provide flexible heat exchange during subsequent rewarming. Here, we tested the hypothesis that peripheral vasodilation could be delayed during this recovery stage. To this end, we designed an experiment to examine patterns of surface rewarming in fully hypothermic (the cloaca and peripheral regions (here; flippers, feet and the breast) < 37 °C) and partially hypothermic (cloaca at normothermia ≥ 37 °C, but periphery at hypothermia) king penguins (Aptenodytes patagonicus) when they rewarmed in the laboratory. Both groups rewarmed during the 21 min observation period, but the temperature changes were larger in fully than in partially hypothermic birds. Moreover, we observed a 5 min delay of peripheral temperature in fully compared to partially hypothermic birds, suggesting that this process was impacted by low internal temperature. To investigate whether our laboratory data were applicable to field conditions, we also recorded surface temperatures of free-ranging penguins after they came ashore to the colony. Initial surface temperatures were lower in these birds compared to in those that rewarmed in the laboratory, and changed less over a comparable period of time on land. This could be explained both by environmental conditions and possible handling-induced thermogenesis in the laboratory. Nevertheless, this study demonstrated that appendage vasodilation is flexibly used during rewarming and that recovery may be influenced by both internal temperature and environmental conditions when penguins transition from sea to land.
Programme: 394
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Agnès Lewden, Batshéva Bonnet, Andreas Nord. (2020). The metabolic cost of subcutaneous and abdominal rewarming in king penguins after long-term immersion in cold water (Vol. 91).
Abstract: Marine endotherms in the polar regions face a formidable thermal challenge when swimming in cold water. Hence, they use morphological (fat, blubber) adjustment and peripheral vasoconstriction to reduce demands for heat production in water. The animals then regain normothermia when resting ashore. In the king penguin (Aptenodytes patagonicus) metabolic rate is lower in fed than in fasted individuals during subsequent rewarming on land. This has been suggested to be a consequence of diversion of blood flow to the splanchnic region in fed birds, which reduces peripheral temperatures. However, peripheral temperatures during recovery have never been investigated in birds with different nutritional status. The aim of this study was, therefore, to measure subcutaneous and abdominal temperatures during the rewarming phase on land in fasted and fed king penguins, and investigate to which extent any different rewarming were reflected in recovery metabolic rate (MRR) after long term immersion in cold water. We hypothesized that fed individuals would have a slower increase of subcutaneous temperatures compared to fasted penguins, and a correspondingly lower MRR. Subcutaneous tissues reached normothermia after 24.15 (back) and 21.36 min (flank), which was twice as fast as in the abdomen (46.82 min). However, recovery time was not affected by nutritional condition. MRR during global rewarming (4.56 ± 0.42 W kg−1) was twice as high as resting metabolic rate (RMR; 2.16 ± 0.59 W kg−1). However, MRR was not dependent on feeding status and was significantly elevated above RMR only until subcutaneous temperature had recovered. Contrary to our prediction, fed individuals did not reduce the subcutaneous circulation compared to fasted penguins and did not show any changes in MRR during subsequent recovery. It seems likely that lower metabolic rate in fed king penguins on land reported in other studies might not have been caused primarily by increased circulation to the visceral organs.
Keywords: Metabolism Normothermia Rewarming Subcutaneous temperature
Programme: 394
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Agnieszka Beszczynska-Möller, Hanne Sagen, Peter Voss, Mikael K. Sejr, Thomas Soltwedel, Truls Johannessen, M.-N. Houssais, Andreas Rogge, Ian Allan, Frank Nilsen, Angelika Renner, L. H. Smedsrud, Nicholas Roden, Jean-Pierre Gattuso, Laurent Chauvaud, Claudie Marec, B. Cheng, Andrew King, Christine Provost, Marcel Babin, Mathilde Sorensen. (2020). Enhancement of ocean and sea ice in situ observations in the Arctic under the Horizon2020 project INTAROS.
Abstract: The H2020 project Integrated Arctic Observation System (INTAROS) aspires to increase the temporal and geographic coverage of in situ observations and add new key geophysical and biogeochemical variables in selected regions of the Arctic. By using a combination of mature and new instruments and sensors in integration with existing observatories, INTAROS aims to fill selected gaps in the present-day system and build additional capacity of the Arctic monitoring networks for ocean and sea ice. Three reference sites have been selected as key locations for monitoring ongoing Arctic changes: Costal Greenland, paramount for freshwater output from the Greenland ice sheet; North of Svalbard (covering the region from shelf to deep basin) – the hot-spot for ocean-air-sea ice interactions, and heat and biological energy input to the European Arctic; and Fram Strait – the critical gateway for exchanges between the Arctic and the World oceans. The existing observatories in the reference sites have been extended with new moorings and novel autonomous instrumentation, in particular for biogeochemical measurements and sea ice observations. Bottom-mounted instruments have been also implemented for seismic observations. A distributed observatory for ocean and sea ice in the Arctic Ocean and sub-Arctic seas includes non-stationary components such as ice-tethered observing platforms, float, gliders, and ships of opportunities, collecting multidisciplinary observations, still missing from the Arctic regions. New sensors, integrated platforms and experimental set-ups are currently under implementation during a two-year long deployment phase (2018-2020) with an aim to evaluate their sustained use in a future iAOS. New observations will be used for integration of new data products, demonstration studies and stakeholder consultations, contributing also to ongoing and future long-term initiatives (e.g. SAON).
Programme: 1141
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Albane Barbero, Camille Blouzon, Joël Savarino, Nicolas Caillon, Aurélien Dommergue, Roberto Grilli. (2020). A compact incoherent broadband cavity-enhanced absorption spectrometer for trace detection of nitrogen oxides, iodine oxide and glyoxal at levels below parts per billion for field applications (Vol. 13). Bachelor's thesis, , .
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Alexander Winterl, Sebastian Richter, Aymeric Houstin, Anna P. Nesterova, Francesco Bonadonna, Werner Schneider, Ben Fabry, Céline Le Bohec, Daniel P. Zitterbart. (2020). micrObs – A customizable time-lapse camera for ecological studies (Vol. 8).
Abstract: Camera traps for motion-triggered or continuous time-lapse recordings are readily available on the market. For demanding applications in ecology and environmental sciences, however, commercial systems often lack flexibility to freely adjust recording time intervals, suffer from mechanical component wear, and can be difficult to combine with auxiliary sensors such as GPS, weather stations, or light sensors. We present a robust time-lapse camera system that has been operating continuously since 2013 under the harsh climatic conditions of the Antarctic and Subantarctic regions. Thus far, we have recorded over one million images with individual cameras. The system consumes 122 mW of power in standby mode and captures up to 200,000 high-resolution (16 MPix) images without maintenance such as battery or image memory replacement. It offers time-lapse intervals between 2 s and 1 h, low-light or night-time power saving, and data logging capabilities for additional inputs such as GPS and weather data.
Keywords: Automated camera system Collective behavior Ecology Image processing Remote sensing Wildlife monitoring
Programme: 137
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Alexandra Lavrillier. (2020). “Spirit-Charged” Humans in Siberia: Interrelations between the Notions of the Individual (“Spirit Charge” and “Active Imprint”) and (Ritual) Action (Vol. 57).
Abstract: This paper shows how a society imagines human individuals and their power to act upon spirits both ritually and materially. Based on the author’s fieldwork (from 1994 to 2019), it analyzes the emic concept onnir, which is omnipresent in the daily activities and the past and present collective/individual rituals of Siberian Evenki and Even. Each human owns a specific fluctuating “charge made of spirits” and an “active imprint” that empowers the human to act, perform rituals, develop talents, and create. Even after death, this “imprint” affects everything and everyone a human ever touched. Onnir defines the interrelations between the individual, the spirits of his or her own “charge,” and the spirits of the universe in an “active agent”-“patient” relationship. This paper contributes to studies of the notions of the individual, “playing” as a ritual means, the acceptance/rejection of neoshamans, neorituals, and the (ritual) agency of ordinary individuals.
Programme: 1127
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