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Author Jun Xie, Risheng Chu, Sidao Ni
Title Evaluating Global Tomography Models With Antipodal Ambient Noise Cross-Correlation Functions Type Journal
Year 2021 Publication Journal of Geophysical Research: Solid Earth Abbreviated Journal
Volume 126 Issue 3 Pages e2020JB020444
Keywords ambient noise cross-correlation functions antipodal surface waves mantle heterogeneity tomography model evaluation
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Programme 133
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-9356 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7993
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Author R. Olmi, M. Bittelli, G. Picard, L. Arnaud, A. Mialon, S. Priori
Title Investigating the influence of the grain size and distribution on the macroscopic dielectric properties of Antarctic firn Type Journal
Year 2021 Publication Cold Regions Science and Technology Abbreviated Journal
Volume 185 Issue Pages 103254
Keywords Antarctica Close?off Dielectric measurements Dielectric model Firn Full wave EM simulations Ice cores
Abstract
Programme 1110
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Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0165-232X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7995
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Author A. Baranov, R. Tenzer, A. Morelli
Title Updated Antarctic crustal model Type Journal
Year 2021 Publication Gondwana Research Abbreviated Journal
Volume 89 Issue Pages 1-18
Keywords Antarctica Crustal structure Gondwana Sediments
Abstract
Programme 133
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Series Editor Series Title Abbreviated Series Title
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ISSN 1342-937X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7994
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Author
Title Radar altimeter waveform simulations in Antarctica with the Snow Microwave Radiative Transfer Model (SMRT) Type Journal
Year 2021 Publication Remote Sensing of Environment Abbreviated Journal
Volume 263 Issue Pages 112534
Keywords Antarctic ice sheet Field measurements Modeling Radar altimetry Remote sensing SMRT Waveform
Abstract Radar altimeters are important tools to monitor the volume of the ice sheets. The penetration of radar waves in the snowpack is a major source of uncertainty to retrieve surface elevation. To correct this effect, a better understanding of the sensitivity of the radar waveforms to snow properties is needed. Here, we present an extension of the Snow Model Radiative Transfer (SMRT) to compute radar waveforms and conduct a series of simulations on the Antarctic ice sheet. SMRT is driven by snow and surface roughness properties measured over a large latitudinal range during two field campaigns on the Antarctic Plateau. These measurements show that the snowpack is rougher, denser, less stratified, warmer, and has smaller snow grains near the coast than on the central Plateau. These simulations are compared to satellite observations in the Ka, Ku, and S bands. SMRT reproduces the observed waveforms well. For all sites and all sensors, the main contribution comes from the surface echo. The echo from snow grains (volume scattering) represents up to 40% of the amplitude of the total waveform power in the Ka band, and less at the lower frequencies. The highest amplitude is observed on the central Plateau due to the combination of higher reflection from the surface, higher scattering by snow grains in the Ka and Ku bands, and higher inter-layer reflections in the S band. In the Ka band, the wave penetrates in the snowpack less deeply on the central Plateau than near the coast because of the strong scattering caused by the larger snow grains. The opposite is observed in the S band, the wave penetrates deeper on the central Plateau because of the lower absorption due to the lower snow temperatures. The elevation bias caused by wave penetration into the snowpack show a constant bias of 10 cm for all sites in the Ka band, and a bias of 11 cm, and 21 cm in the Ku band for sites close to the coast and the central Plateau, respectively. Now that SMRT is performing waveform simulations, further work will address how the snowpack properties affect the parameters retrieved by more advanced retracking algorithms such as ICE-2 for different snow cover surfaces.
Programme 1110
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Series Editor Series Title Abbreviated Series Title
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ISSN 0034-4257 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 7997
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Author Pierre-Yves Pascal, Yann Reynaud, Elie Poulin, Chantal De Ridder, Thomas Saucede
Title Feeding in spatangoids: the case of Abatus Cordatus in the Kerguelen Islands (Southern Ocean) Type Journal
Year 2021 Publication Polar Biology Abbreviated Journal
Volume 44 Issue 4 Pages 795-808
Keywords
Abstract Irregular urchins exclusively live in marine soft bottom habitats, dwelling either upon or inside sediments and selectively picking up sediment grains and organic particles, or swallowing bulk sediment to feed on the associated organic matter. The exact food source and dietary requirements of most irregular echinoids, however, remain incompletely understood. The schizasterid species Abatus cordatus (Verrill, 1876) is a sub-Antarctic spatangoid that is endemic to the Kerguelen. The feeding behaviour of A. cordatus was investigated using simultaneously metabarcoding and stable isotope approaches. Comparison of ingested and surrounding sediments by metabarcoding revealed a limited selective ingestion of prokaryotes and eukaryotes by the urchin. Compared to surrounding sediments, the gut content had (i) higher carbon and nitrogen concentrations potentially due to selective ingestion of organic matter and/or the sea urchin mucus secretion and (ii) ?15N enrichment due to the selective assimilation of lighter isotope in the gut. Feeding experiments were performed using 13C and 15 N-enriched sediments in aquariums. The progression of stable isotope enrichment in proximal and distal parts of the digestive track of A. cordatus revealed that all particles are not similarly transported likely due to siphon functioning. Ingestion of water with associated dissolved and particulate organic matter should play an important role in urchin nutrition. A. cordatus had a gut resident time fluctuating between 76 and 101 h and an ingestion rate of 36 mg dry sediment h?1 suggesting that dense populations of the species may play a key ecological role through bioturbation in soft bottom shallow-water habitats of the Kerguelen Islands.
Programme 1044
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Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-2056 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8000
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Author
Title Individual-based model of population dynamics in a sea urchin of the Kerguelen Plateau (Southern Ocean), Abatus cordatus, under changing environmental conditions Type Journal
Year 2021 Publication Ecological Modelling Abbreviated Journal
Volume 440 Issue Pages 109352
Keywords Climate change Dynamic energy budget Ecological modelling Endemic echinoderm Individual-based model Kerguelen Model sensitivity
Abstract
Programme 1044
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Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0304-3800 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8002
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Author
Title Divergence time and species delimitation of microbivalves in the Southern Ocean: the case of Kidderia species Type Journal
Year 2021 Publication Polar Biology Abbreviated Journal
Volume 44 Issue 7 Pages 1365-1377
Keywords
Abstract The systematics of Subantarctic and Antarctic near-shore marine benthic invertebrates requires major revision and highlights the necessity to incorporate additional sources of information in the specimen identification chart in the Southern Ocean (SO). In this study, we aim to improve our understanding of the biodiversity of Kidderia (Dall 1876) through molecular and morphological comparisons of Antarctic and Subantarctic taxa. The microbivalves of the genus Kidderia are small brooding organisms that inhabit intertidal and shallow subtidal rocky ecosystems. This genus represents an interesting model to test the vicariance and dispersal hypothesis in the biogeography of the SO. However, the description of Kidderia species relies on a few morphological characters and biogeographic records that raise questions about the true diversity in the group. Here we will define the specimens collected with genetic tools, delimiting their respective boundaries across provinces of the SO, validating the presence of two species of Kidderia. Through the revision of taxonomic issues and species delimitation, it was possible to report that the Antarctic species is Kidderia subquadrata and the species recorded in the Subantarctic islands Diego Ramirez, South Georgia and the Kerguelen Archipelago is Kidderia minuta. The divergence time estimation suggests the origin and diversification of Kidderia lineages are related to historical vicariant processes probably associated with the separation of the continental landmasses close to the late Eocene.
Programme 1044
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-2056 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8004
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Author
Title Is the southern crab Halicarcinus planatus (Fabricius, 1775) the next invader of Antarctica? Type Journal
Year 2021 Publication Global Change Biology Abbreviated Journal
Volume 27 Issue 15 Pages 3487-3504
Keywords climate change establishment niche modelling non-native species reptant crab Southern Ocean survival thermotolerance
Abstract
Programme 1044
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Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1365-2486 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8005
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Author
Title Ground-based validation of the Copernicus Sentinel-5P TROPOMI NO2 measurements with the NDACC ZSL-DOAS, MAX-DOAS and Pandonia global networks Type Journal
Year 2021 Publication Atmospheric Measurement Techniques Abbreviated Journal
Volume 14 Issue 1 Pages 481-510
Keywords
Abstract This Paper Reports On Consolidated Ground-based Validation Results Of The Atmospheric No2 Data Produced Operationally Since April 2018 By The Tropospheric Monitoring Instrument (Tropomi) On Board Of The Esa/eu Copernicus Sentinel-5 Precursor (S5p) Satellite. Tropospheric, Stratospheric, And Total No2 Column Data From S5p Are Compared To Correlative Measurements Collected From, Respectively, 19 Multi-axis Differential Optical Absorption Spectroscopy (Max-doas), 26 Network For The Detection Of Atmospheric Composition Change (Ndacc) Zenith-scattered-light Doas (Zsl-doas), And 25 Pandonia Global Network (Pgn)/pandora Instruments Distributed Globally. The Validation Methodology Gives Special Care To Minimizing Mismatch Errors Due To Imperfect Spatio-temporal Co-location Of The Satellite And Correlative Data, E.g. By Using Tailored Observation Operators To Account For Differences In Smoothing And In Sampling Of Atmospheric Structures And Variability And Photochemical Modelling To Reduce Diurnal Cycle Effects. Compared To The Ground-based Measurements, S5p Data Show, On Average, (I) A Negative Bias For The Tropospheric Column Data, Of Typically ?23 % To ?37 % In Clean To Slightly Polluted Conditions But Reaching Values As High As ?51 % Over Highly Polluted Areas; (Ii) A Slight Negative Median Difference For The Stratospheric Column Data, Of About ?0.2 Pmolec Cm?2, I.e. Approx. ?2 % In Summer To ?15 % In Winter; And (Iii) A Bias Ranging From Zero To ?50 % For The Total Column Data, Found To Depend On The Amplitude Of The Total No2 Column, With Small To Slightly Positive Bias Values For Columns Below 6 Pmolec Cm?2 And Negative Values Above. The Dispersion Between S5p And Correlative Measurements Contains Mostly Random Components, Which Remain Within Mission Requirements For The Stratospheric Column Data (0.5 Pmolec Cm?2) But Exceed Those For The Tropospheric Column Data (0.7 Pmolec Cm?2). While A Part Of The Biases And Dispersion May Be Due To Representativeness Differences Such As Different Area Averaging And Measurement Times, It Is Known That Errors In The S5p Tropospheric Columns Exist Due To Shortcomings In The (Horizontally Coarse) A Priori Profile Representation In The Tm5-mp Chemical Transport Model Used In The S5p Retrieval And, To A Lesser Extent, To The Treatment Of Cloud Effects And Aerosols. Although Considerable Differences (Up To 2 Pmolec Cm?2 And More) Are Observed At Single Ground-pixel Level, The Near-real-time (Nrti) And Offline (Offl) Versions Of The S5p No2 Operational Data Processor Provide Similar No2 Column Values And Validation Results When Globally Averaged, With The Nrti Values Being On Average 0.79 % Larger Than The Offl Values.
Programme 209
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1867-1381 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8013
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Author Lucia Gualtieri, Etienne Bachmann, Frederik J Simons, Jeroen Tromp
Title Generation of secondary microseism Love waves: effects of bathymetry, 3-D structure and source seasonality Type Journal
Year 2021 Publication Geophysical Journal International Abbreviated Journal
Volume 226 Issue 1 Pages 192-219
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Abstract
Programme 133
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Corporate Author Thesis
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Language Summary Language Original Title (up)
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0956-540X ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8016
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