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Albertin, S., Savarino, J., Bekki, S., T. Roberts, T., Barret, B., Mao, J., Simpson, W., Law, K. (2021). Isotopic constraints on the sources and fate of atmospheric nitrate in Fairbanks, Alaska: preliminary results of the pre-ALPACA campaign.
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Guillaume Hubert. (2021). Continuously Measurements of Energy Spectra of Cosmic-Ray-induced-neutrons on the Concordia Antarctic Station for the period 2015-2021 (Vol. 395).
Abstract: The CHINSTRAP (Continuous High-altitude Investigation of the Neutron Spectra for Terrestrial Radiation Antarctic Project) supported by the French Polar Agency (IPEV) aims at recording cosmic-ray (CR) induced-neutron spectra at the Concordia station since December 2015. The neutron spectrometer measures the neutron spectrum over a wide energy range from meV up to tens of GeV with a short time resolution. Several parameters can influence the measurement, including systematic and environmental effects such as the atmospheric pressure, the hydrometric environment close to the instrument and the atmospheric water vapor. This paper presents CR induced neutrons measurements analyses from 2015 to 2021 in Concordia, integrating corrections to take into account environmental and systematic effects. Long-term and short-term analyses are proposed, applied to count rate, fluxes and spectra. A last part investigates the contribution of modelling to data analyses and the ability to deduce the solar modulation from neutron spectra and the radiation field extrapolation using nuclear transport in atmosphere. An underlying objective is also to improve physical models allowing analyses of continuous and simultaneously measurements of CR induced neutrons spectra.
Programme: 1112
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Najat Bhiry, Dominique Marguerie, Tommy Weetaluktuk, Myosotis Desroches Bourgon, David Aoustin, Pierre M. Desrosiers, Dominique Todisco. (2021). Dorset and Thule Inuit occupations of Qikirtajuaq (Smith Island), Nunavik, Canada: a palaeoecological approach (Vol. Boreas).
Abstract: Qikirtajuaq is a long island facing the Inuit village of Akulivik on the northeastern coast of Hudson Bay (Canada) that is rich in archaeological sites. Kangiakallak-1 (JeGn-2), one of the main sites on this island, is a large multicomponent site that includes Dorset and Thule Inuit winter houses. This study documents the dynamics of palaeoenvironmental conditions in the successive occupations of the Kangiakallak-1 settlement based on plant macrofossils, pollen and non-pollen palynomorph analyses and archaeological research. The data indicate that Dorset inhabitants constructed their dwelling at about 772 cal. a BP. The site was reused by the Thule Inuit a few decades later, starting at about 671 cal. a BP. Thus, Kangiakallak-1 is one of the few sites, at least in Nunavik (northern Quebec, Canada), that were rapidly reoccupied by the Thule Inuit after the departure of the Dorset inhabitants, which indicates a possible overlap between the two cultures in the Akulivik region. The palaeoecological data show that both Dorset and Thule inhabitants left clear footprints at the local scale in the form of several nitrophilous species that became established in and near the houses and persisted over a long period. The deposition of domestic waste (including bone fragments, skin, burnt fat and charcoal fragments) inside the subterranean dwellings fertilized the soil and led to the growth of unique nitrophilous plants. These changes transformed the houses into exceptional floristic refuges.
Programme: 1080
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. (2021). Evolutionary Genetics of Borrelia (Vol. 42).
Abstract: The genus Borrelia consists of evolutionarily and genetically diverse bacterial species that cause a variety of diseases in humans and domestic animals. These vector-borne spirochetes can be classified into two major evolutionary groups, the Lyme borreliosis clade and the relapsing fever clade, both of which have complex transmission cycles during which they interact with multiple host species and arthropod vectors. Molecular, ecological, and evolutionary studies have each provided significant contributions towards our understanding of the natural history, biology and evolutionary genetics of Borrelia species; however, integration of these studies is required to identify the evolutionary causes and consequences of the genetic variation within and among Borrelia species. For example, molecular and genetic studies have identified the adaptations that maximize fitness components throughout the Borrelia lifecycle and enhance transmission efficacy but provide limited insights into the evolutionary pressures that have produced them. Ecological studies can identify interactions between Borrelia species and the vertebrate hosts and arthropod vectors they encounter and the resulting impact on the geographic distribution and abundance of spirochetes but not the genetic or molecular basis underlying these interactions. In this review we discuss recent findings on the evolutionary genetics from both of the evolutionarily distinct clades of Borrelia species. We focus on connecting molecular interactions to the ecological processes that have driven the evolution and diversification of Borrelia species in order to understand the current distribution of genetic and molecular variation within and between Borrelia species.
Programme: 333
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Simon Thomas, Pierre-Louis Blelly, Aurelie Marchaudon, Julian Eisenbeis, Samuel Bird. (2021). Simulating the Response of the Ionosphere in IPIM to Extreme Space Weather (Vol. 2021).
Abstract: The IRAP Plasmasphere Ionosphere Model (IPIM) is an ionospheric model which describes the transport equations of ionospheric plasma species along magnetic closed field lines. As input, the previous iteration of IPIM used basic models to provide estimations of the solar wind conditions, convection, and precipitation within the ionosphere. In this presentation, we discuss the development of a new operational version of IPIM as part of the EUHFORIA project to monitor and forecast space weather conditions and hazards. The developments of the model include using in-situ solar wind observations from the OMNI data set, ionospheric radar data of plasma motions from the Super Dual Auroral Radar Network (SuperDARN), and precipitation data from the Ovation model, as inputs to the model. A new conductivity module for low latitudes has also been developed for help in the simulation of geomagnetically induced currents. We present the first results from the latest IPIM version which explore the ionosphere's response to different solar wind conditions, before focussing on an extreme coronal mass ejection on 14th July 2012 with clear magnetic cloud and southward magnetic field. For this event, we explore simulations of important plasma properties of the ionosphere and compare with previous model iterations and all available observations and hence describe the skill of using IPIM as a space weather forecasting tool.
Programme: 312
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. (2021). Constraining 20th-Century Sea-Level Rise in the South Atlantic Ocean (Vol. 126).
Keywords: data rescue salt-marsh proxies sea-level changes South Atlantic tide gauges
Programme: 688
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. (2021). (Vol. 21).
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R. Sulzbach, H. Dobslaw, M. Thomas. (2021). High-Resolution Numerical Modeling of Barotropic Global Ocean Tides for Satellite Gravimetry (Vol. 126).
Keywords: M2-tide minor tides pole-rotation self-attraction and loading tide-generating potential topographic wavedrag
Programme: 688
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Andrea Spolaor, Beatrice Moroni, Bart?omiej Luks, Adam Nawrot, Marco Roman, Catherine Larose, ?ukasz Stachnik, Federica Bruschi, Krystyna Kozio?, Filip Pawlak, Clara Turetta, Elena Barbaro, Jean-Charles Gallet, David Cappelletti. (2021). Investigation on the Sources and Impact of Trace Elements in the Annual Snowpack and the Firn in the Hansbreen (Southwest Spitsbergen) (Vol. 8).
Abstract: We present a thorough evaluation of the water soluble fraction of the trace element composition (Ca, Sr, Mg, Na, K, Li, B, Rb, U, Ni, Co, As, Cs, Cd, Mo, Se, Eu, Ba, V, Ge, Ga, Cr, Cr, P, Ti, Mn, Zr, Ce, Zn, Fe, Gd, Y, Pb, Bi, Yb, Al, Nb, Er, Nd, Dy, Sm, Ho, Th, La, Lu, Tm, Pr, Tb, Fe, In, Tl) and their fluxes in the annual snowpack and the firn of the Hansbreen (a tidewater glacier terminating in the Hornsund fjord, southwest Spitsbergen). The trace element samples were obtained from a 3 m deep snow pit dug at the plateau of the glacier (450 m a.s.l.), and from a 2 m deep firn core collected from the bottom of the snow pit. The comparison of elemental fluxes and enrichment factors allowed us to constrain specific summer and wintertime deposition patterns of water soluble trace elements in the southern part of the Svalbard archipelago. Our results suggest that the chemical composition of the Hansbreen (and likely other glaciers where the summit is close to the equilibrium line) is mainly affected by summertime deposition of trace elements from local sources and some volatile elements, which may be transported into the Arctic when polar vortex is weak. The melting of the annual snowpack seems to have a minor influence on the overall chemical signature of the glacier ice.
Programme: 1192
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. (2021). Long-term tracking of an Arctic-breeding seabird indicates high fidelity to pelagic wintering areas (Vol. 676).
Keywords: Biologging Global Location Sensors GLS Individual consistency Migration Nearest neighbor distance Repeatability Spatial distribution
Programme: 330
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