. (2022). HD 28109 hosts a trio of transiting Neptunian planets including a near-resonant pair, confirmed by ASTEP from Antarctica (Vol. 515).
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Morin S, Erbland J, Savarino J, Domine F, Bock J, Friess U, Jacobi H-W, Sihler H, Martins J M F, . (2012). An isotopic view on the connection between photolytic emissions of NOx from the Arctic snowpack and its oxidation by reactive halogens
. J. Geophys. Res., 117, D00R08–.
Keywords: halogen, isotopes, nitrate, ozone, 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801, 4906), 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 0454 Biogeosciences: Isotopic composition and chemistry (1041, 4870), 0736 Cryosphere: Snow (1827, 1863), 9315 Geographic Location: Arctic region (0718, 4207),
Programme: 1017
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. (2017). Biomonitoring of fluoroalkylated substances in Antarctica seabird plasma: Development and validation of a fast and rugged method using on-line concentration liquid chromatography tandem mass spectrometry (Vol. 1513).
Keywords: Antarctica Biomonitoring Method validation On-line solid phase extraction Plasma Polyfluoroalkyl substances Seabird
Programme: 109
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. (2023). Plant consumer innovation in skuas (Vol. 164). Bachelor's thesis, , .
Keywords: Animal innovation Consumer innovation Field observation Novel food Stercorarius antarcticus lonnbergi
Programme: 109,354
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. (2015). High turnover rates indicated by changes in the fixed N forms and their stable isotopes in Antarctic landfast sea ice (Vol. 120).
Abstract: We report concentration and nitrogen and oxygen isotopic measurements of nitrate, total dissolved nitrogen, and particulate nitrogen from Antarctic landfast sea ice, covering almost the complete seasonal cycle of sea ice growth and decay (from April to November). When sea ice forms in autumn, ice algae growth depletes nitrate and accumulates organic N within the ice. Subsequent low biological activity in winter imposes minor variations in the partitioning of fixed N. In early spring, the coupling between nitrate assimilation and brine convection at the sea ice bottom traps a large amount of fixed N within sea ice, up to 20 times higher than in the underlying seawater. At this time, remineralization and nitrification also accelerate, yielding nitrate concentrations up to 5 times higher than in seawater. Nitrate ?15N and ?18O are both elevated, indicating a near-balance between nitrification and nitrate assimilation. These findings require high microbially mediated turnover rates for the large fixed N pools, including nitrate. When sea ice warms in the spring, ice algae grow through the full thickness of the ice. The warming stratifies the brine network, which limits the exchange with seawater, causing the once-elevated nitrate pool to be nearly completely depleted. The nitrate isotope data point to light limitation at the base of landfast ice as a central characteristic of the environment, affecting its N cycling (e.g., allowing for nitrification) and impacting algal physiology (e.g., as reflected in the N and O isotope effects of nitrate assimilation).
Keywords: Antarctic isotopes nitrogen nutrients sea ice
Programme: 1010
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. (2020).
Keywords: cosmogenic nuclide dating deglaciation exhumation fission-track dating Late Palaeozoic Ice Age subglacial incision
Programme: 1003
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Francia, P.; Lanzerotti, L.J.; Villante, U.; Lepidi, S.; Di Memmo, D. (2005). A statistical analysis of low-frequency magnetic pulsations at cusp and cap latitudes in Antarctica. J. Geophys. Res., 110.
Keywords: polar cap and cusp pulsations; magnetospheric wave guide modes; field line resonances; open/closed field line boundary; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions; 2740 Magnetospheric Physics: Magnetospheric configuration and dynamics; 2776 Magnetospheric Physics: Polar cap phenomena; 2706 Magnetospheric Physics: Cusp; 2752 Magnetospheric Physics: MHD waves and instabilities
Programme: 1130
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. (2006). Revised spherical cap harmonic analysis (R-SCHA): Validation and properties. J. Geophys. Res., 111.
Abstract: We recently proposed a technique able to represent the spatial variations of the magnetic field at regional scales. However, we pointed out that these preliminary developments were not suited for the complete representation of the geomagnetic field. In this paper, we propose a complete revision, the revised spherical cap harmonic analysis (R-SCHA), which introduces slight changes in order to rectify the previous shortcomings. In addition, some discussions shed a new light on the former spherical cap harmonic analysis (SCHA) and help us to demonstrate its deficiencies and approximations. We finally show that R-SCHA now fully satisfies the natural properties of potential fields. R-SCHA also yields analytical relationships with the spherical harmonics. Taking advantage of the mathematical equivalence of both representations, we explore the relevance of fundamental concepts like spectrum, minimum wavelength, or internal/external field separation. We conclude that these concepts are misleading and must be handled with care in regional modeling. A prime goal being the ability of R-SCHA to represent real data sets, we also investigate and illustrate the effect of finite series expansions. A norm for the regularization of the inverse problem is proposed as well. The conclusions drawn in this paper allow us to validate the method and to assert that the present proposal is suited for modeling and studying the lithospheric magnetic field from ground to satellite altitudes at regional scales.
Keywords: magnetism; regional modeling; Spherical Cap Harmonic Analysis; 1214 Geodesy and Gravity: Geopotential theory and determination; 1517 Geomagnetism and Paleomagnetism: Magnetic anomalies: modeling and interpretation; 1532 Geomagnetism and Paleomagnetism: Reference fields: regional, global; 1541 Geomagnetism and Paleomagnetism: Satellite magnetics: main field, crustal field, external field; 1545 Geomagnetism and Paleomagnetism: Spatial variations: all harmonics and anomalies
Programme: 139;905
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Yushiro Fujii, Kenji Satake, Shingo Watada, Tung-Cheng Ho. (2021). (Vol. 178).
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Schimmel M, Stutzmann E, Ardhuin F, Gallart J, . (2011). Polarized Earth's ambient microseismic noise
. 1525-2027, 12(7), Q07014–.
Abstract: We quantify, analyze, and characterize the frequency-dependent microseismic noise recorded by worldwide distributed seismic stations. Microseismic noise is generated through the interaction of ocean waves. It is the strongest ambient noise, and it is observed everywhere on Earth. We introduce a new approach which permits us to detect polarized signals in the time-frequency domain and which we use to characterize the microseismic noise. We analyze 7 years of continuous seismograms from the global GEOSCOPE network. Microseisms are dominated by Rayleigh waves, and we therefore focus on elliptically polarized signals. The polarized signals are detected in the time-frequency domain through a degree of polarization measure. We design polarization spectra and show that microseismic noise is more strongly polarized than noise in other frequency bands. This property is used to measure the directions of the polarized noise at individual stations as a function of time and frequency. Seasonal variations are found for the back azimuths and for the number of polarized signals at many stations. We show that the back azimuth directions are robust measurements that point toward the source areas computed from ocean wave models.
Keywords: microseismic noise, polarization, primary and secondary microseisms, seismology, 7255 Surface waves and free oscillations, 7299 General or miscellaneous,
Programme: 133
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