Hochstrasser-Petit Ch., Romanova L., Duchesne S., Melnichuk O., Gérard P. (2020). Yakut clothes of the 17th and 18th centuries, archaeology and restitution. (Vol. 4).
Abstract: 40 Frozen Yakutian Graves, From The 17th To The 19th Century Allow The Reconstitution Of Clothes. At The End Of the 17th Century, New Fashions Are Emerging With The Ostentatious Use Of Imported Goods And The Influences Of russian Noble Circles And Chinese And/or Mongol And/or Buriat Fashions. The Garment Does Not Only Seem To Be any More An Element Of Protection Against The Cold And A Utilitarian Object But Becomes A Way To Marking The Socialization of The Individual.
Programme: 1038
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Houstin A. (2020). At-sea ecology of the Emperor penguin (Aptenodytes forsteri): Foraging strategies and evaluation of methodological and conservation tools /// Ecologie en mer du manchot empereur (Aptenodytes Forsteri) : stratégies spatio-temporelles de prospection et de recherche alimentaire et évaluation des outils méthodologiques et de conservation.
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I. Wardinski, D. Saturnino, H. Amit, A. Chambodut, B. Langlais, M. Mandea, E. Thébault. (2020). Geomagnetic core field models and secular variation forecasts for the 13th International Geomagnetic Reference Field (IGRF-13) (Vol. 72).
Abstract: Observations of the geomagnetic field taken at Earth’s surface and at satellite altitude are combined to construct continuous models of the geomagnetic field and its secular variation from 1957 to 2020. From these parent models, we derive candidate main field models for the epochs 2015 and 2020 to the 13th generation of the International Geomagnetic Reference Field (IGRF). The secular variation candidate model for the period 2020–2025 is derived from a forecast of the secular variation in 2022.5, which results from a multi-variate singular spectrum analysis of the secular variation from 1957 to 2020.
Keywords: Forecasts of the geomagnetic field Geomagnetic field models Geomagnetic secular variation The geomagnetic field
Programme: 139
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Isabelle Badenhausser, Lise Chambrin, Marc Lebouvier. (2020). Guide d'identification des plantes des îles sub-Antarctiques Crozet et Kerguelen.
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Ishino S., Hattori S., Savarino J., Legrand M., Albalat E., Albarède F., Preunkert S., Jourdain B., Yoshida N. (2020). Homogeneous sulfur isotope signature in East Antarctica and implication for sulfur source shifts through the last glacial-interglacial cycle.
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J Mathurin, E Dartois, C Engrand, J Duprat, A Deniset- Besseau, A Dazzi, Y Kebukawa, T Noguchi, D Troadec. (2020). Nanometre-scale infrared chemical imaging (AFM-IR) of organic matter in ultra-carbonaceous Antarctic micrometeorites (UCAMMS) and future analyses of Hayabusa 2 samples..
Abstract: Introduction: The chemical composition of organic matter (OM) in interplanetary samples (meteorites and micrometeorites) is suitably characterized by the distribution of the different chemical bonds using infrared (IR) vibrational spectroscopy (see e.g. [1]). Classical IR microscopy provides a global view of the dust grain chemical structure content but remains limited by the diffraction, with typical spot sizes sampling a few micrometers in the mid-IR range. This spatial resolution limitation is well above that of complementary techniques such as isotopic imaging with NanoSIMS or transmission electron or X-ray microscopy techniques. These techniques reveal mineralogical, chemical and isotopic heterogeneities at the sub-micron scale but do not give full access to the distribution of the various chemical bonds. The IR diffraction limitation can be circumvented by using AFM-IR microscopy. This technique opens a new window for studies of OM at ten to tens of nanometer scales and will be of importance for studies of the samples from carbonaceous asteroid Ryugu, returned by the Hayabusa 2 space probe in December 2020. AFM-IR is now a well-established microscopy technique in the vibrational field. It combines an atomic force microscope (AFM) and a tunable IR source to detect photo-thermal effect and access chemical information down to a nanoscale resolution [2]. This technique is now applied in a wide diversity of scientific fields [3], and was recently used to analyze extraterrestrial OM [4, 5]. We report here on recent results obtained on imaging two UltraCarbonaceous Antarctic MicroMeteorites (UCAMMs) using AFM-IR [5]. A small fraction of the Antarctic micrometeorites from the Concordia collection consists in UCAMMs, particles with extreme concentrations in OM, most of them exhibiting large deuterium excesses [6]. UCAMMs are also found in Japanese interplanetary dust collections [7-9]. These UCAMMs most likely originate from the surface of small icy bodies in the outer regions of the solar system [1,6,7,10]. The large OM fraction of UCAMMs (considerably higher than in the most carbon-rich meteorites) enables direct analyses without the pre-treatment generally applied to extract the OM from other meteoritic samples, and give access to unaltered chemical maps of the intimate association of minerals and organics.
Programme: 1120
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J Rojas, J Duprat, E Dartois, T-D Wu, C Engrand, B Augé, J Mathurin, B Guerin, J-L Guerquin-Kern, Ph Boduch, H Rothard. (2020). Isotopic analyses of ion irradiation-induced organic residues, clues on the formation of organics from UCAMMS (Vol. 51).
Abstract: Introduction: UltraCarbonaceous Antarctic Mi-croMeteorites (UCAMMs) are interplanetary dust particles that exhibit large concentrations of organic matter with high N concentrations and extreme D/H ratios [1-4]. The mineralogy, the elemental and isotopic composition of UCAMMs indicate that they most likely originate from the cometary reservoir [1, 2, 5]. Most UCAMMs exhibit large variations on D/H, 15 N/ 14 N and 13 C/ 12 C ratios at the micron or sub-micron scale. These isotopic fractionations are carried by the organic matter and their origin is still an open question. We showed that the precursors of UCAMMs can be formed by irradiation with high energy ions of N-rich ice mixtures with hydrocarbons, a process likely to take place at the surface of icy bodies orbiting beyond a nitrogen snow line and irradiated by galactic cosmic rays [2, 6]. Recent experimental simulations showed that the irradiation itself does not induce large D fractionation, but that the refractory organic residue resulting from irradiation of isotopically heterogeneous ice mixtures can exhibit large D/H spatial variation at the micron scale [7]. We performed a new series of experiments on D, 15 N and 13 C labelled ices to study the transmission of the isotopic labelled ice layers to the irradiation-induced residue. Material and method: Irradiation experiments of ices were conducted with the low-energy beam (Irrsud, 0.5-1 MeV/n) at GANIL (Caen, France). We used the IGLIAS experimental setup [8] which allows to deposit and irradiate complex ice films mixtures on substrate windows held at temperatures ranging from 8K to 300K (Figure 1). The evolution of the ices during the irradiation was monitored in situ with a Brucker Vertex 70v Fourier transform infrared (FTIR) spectrometer. The gas mixtures deposited are controlled with a Quadrupole Mass Spectrometer (QMS). We followed the same protocol as described in [7]. We first irradiated a mixture of ices made of two equally thick layers of 14 N2-CH4 (90:10) of about 5 µm each surrounding a thin layer of isotopically labeled (in D, 13 C and 15 N) ice with a thickness of about 0.2 µm. The ice films were formed by gas injections on ZnSe windows at 8K. The thickness of the central isotopically labeled ice layer was estimated from the volume of gases injected (i.e. 2% of the total thickness). The overall thickness of the ice sandwiches (11 µm) were
Programme: 1120
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J Rojas, J Duprat, L R Nittler, J Mathurin, E Dartois, C Engrand, N Bardin, A Dazzi, A Deniset-Besseau, M Godard, J-L Guerquin-Kern, B Guerin, S Moste- Faoui, L Rémusat, R M Stroud, T-D Wu. (2020). The isotopic diversity of ultracarbonaceous Antarctic micrometeorites, a coupled nanosims and afmir study (Vol. 2326).
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J. Díaz, M. Ruiz, J. J. Curto, J. M. Torta, J. Ledo, A. Marcuello, P. Queralt. (2020). On the observation of magnetic events on broad-band seismometers (Vol. 72).
Abstract: The objective of this contribution is to get new insights into the effects of magnetic field variations of natural and anthropogenic origin on broad-band seismic stations. Regarding natural sources of magnetic perturbations, we have investigated if the Sudden Storm Commencements (SSC) cataloged during the 24th solar cycle (2008–2019) can be systematically identified in broad-band seismic stations distributed worldwide. The results show that the 23 SSC events with a mean amplitude above 30 nT and most of those with lower energy but still clearly identified in the magnetometer detection network can be observed at broad-band stations’ network using a simple low-pass filter. Although the preliminary impulse of those signals is usually stronger at stations located at high latitudes, major SSC are observed at seismic stations distributed worldwide. Regarding anthropogenic sources, we focus on the short period seismic signals recorded in urban environments which are correlated with the activity of the railway transportation system. We have analyzed collocated measurements of electric field and seismic signals within Barcelona, evidencing that significant changes in the electric field following the activity of the transportation systems can be attributed to leakage currents transmitted to the soil by trains. During space weather events, electric currents in the magnetosphere and ionosphere experience large variations inducing telluric currents near the Earth surface, which in turn generate a secondary magnetic field. In the case of underground trains, leakage currents are transmitted to the soil, which in turn can result in local variations in the magnetic field. The observed signals in modern seismometers can be related to the reaction of the suspension springs to these magnetic field variations or to the effect of the magnetic field variations on the force transducers used to keep the mass fixed.
Keywords: Anthropogenic sources of magnetic noise Seismic instrumentation Sudden Storm Commencements
Programme: 133
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J. Jumelet, A. R. Klekociuk, S. P. Alexander, S. Bekki, A. Hauchecorne, J. P. Vernier, M. Fromm, P. Keckhut. (2020). Detection of Aerosols in Antarctica From Long-Range Transport of the 2009 Australian Wildfires (Vol. 125).
Abstract: We analyze the long-range transport to high latitudes of a smoke particle filament originating from the extratropics plume after the Australian wildfires colloquially known as “Black Saturday” on 7 February and report the first Antarctic stratospheric lidar characterization of such aerosols. Using a high-resolution transport/microphysical model, we show that the monitoring cloud/aerosol lidar instrument operating at the French Antarctic station Dumont d'Urville (DDU, 66°S to 140°E) recorded a signature of those aerosols. The 532 nm scattering ratio of this filament is comparable to typical moderate stratospheric volcanic plume, with values between 1.4 and 1.6 on the first and third days of March above DDU station at around the 14 and 16 km altitude, respectively. A dedicated model is described and its ability to track down fine optical signatures is validated against Antarctic lidar elastic aerosol and DIAL ozone measurements. Using 1 month of tropical Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data to support a relatively simple microphysical scheme, we report modeled aerosol presence above DDU station after advection of the aerosol size distribution. In situ measurements also report associated positive ozone anomaly. This case study provides evidence that biomass burning events injecting significant amounts of material up to stratospheric altitudes can be transported toward high latitudes. We highlight a potential imprint of smoke particles on the Antarctic atmosphere over larger time scales. Any underestimation of the global impact of such deep particle transport will lead to uncertainties in modeling the associated chemical or radiative effects, especially in polar regions, where specific microphysical and chemical processes take place.
Keywords: aerosols Antarctica bushfires lidar
Programme: 209
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