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Author Magand, O., Le Meur, E., Chappellaz, J., Savarino, J., and Favier, V.:
Title A new scientific traverse in an unexplored area of East Antarctica SCAR Open Science Conference, Auckland, NZ Type Conference - International - Article with Reading Comitee
Year 2014 Publication Abbreviated Journal
Volume Issue Pages
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Programme (up) 1011
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Area Expedition Conference
Notes Approved yes
Call Number Serial 5976
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Author Gautier, E., Savarino, J., Farquhar, J., and Erbland, J.:
Title A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, The 7th International Symposium on Isotopomers, Tokyo, Japan Type Conference - International - Article with Reading Comitee
Year 2014 Publication Abbreviated Journal
Volume Issue Pages
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Programme (up) 1011
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Corporate Author Thesis
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Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved yes
Call Number Serial 5979
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Author Leglise Joris
Title Variabilité interannuelle du nitrate sur le plateau Antarctique Type Master
Year 2015 Publication Abbreviated Journal
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Programme (up) 1011
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Corporate Author Thesis
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Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes Approved yes
Call Number Serial 6222
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Author Savarino, J., Gautier, E., Petit, J.-R., Michel, A., Metrich, N., Besson, P., Vidal, C. M., Komorowski, J.-C., and Lavigne, F.
Title Geochemical DNA or the identification of the 1259 AD volcanic glasses in ice cores, Our common futur under climate change, UNESCO, Paris. Type Conference - International - Article with Reading Comitee
Year 2015 Publication Abbreviated Journal
Volume Issue Pages
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Programme (up) 1011
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 6223
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Author Kukui, A., Preunkert, S., Legrand, M., and Savarino, J.:
Title The Oxidant Production over Antarctic Land and its Export (OPALE) project: An overview of data collected in summer 2011-2012 at Concordia, EGU General Assembly, Vienna, Austria Type Conference - International - Article with Reading Comitee
Year 2015 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme (up) 1011
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Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 6224
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Author Ishino, S., Hattori, S., Caillon, N., Barbero, A., Gautier, E., Jourdain, B., Legrand, M., Preunkert, S., Yoshida, N., and Savarino, J.
Title Seasonal variations of nitrogen and oxygen isotopic signature of atmospheric nitrate in coastal Antarctica, 10th Japan Geoscience Union Meeting 2015, Makuhari Messe, Chiba, Japan Type Conference - National - Article with Reading Comitee
Year 2015 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme (up) 1011
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Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 6225
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Author Gautier, E., Savarino, J., and Farquhar, J.:
Title A reconstruction of terrestrial volcanism over the last 2500 years using sulfur isotopes in ice-cores, Our common futur under climate change, UNESCO, Paris Type Conference - International - Article with Reading Comitee
Year 2015 Publication Abbreviated Journal
Volume Issue Pages
Keywords
Abstract
Programme (up) 1011
Campaign
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 6226
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Author T. A. Berhanu, J. Savarino, J. Erbland, W. C. Vicars, S. Preunkert, J. F. Martins, M. S. Johnson
Title Isotopic effects of nitrate photochemistry in snow: a field study at Dome C, Antarctica Type Journal
Year 2015 Publication Atmospheric Chemistry and Physics Abbreviated Journal
Volume 15 Issue 19 Pages 11243-11256
Keywords
Abstract Abstract. Stable Isotope Ratios Of Nitrate Preserved In Deep Ice Cores Are Expected To Provide Unique And Valuable Information Regarding Paleoatmospheric Processes. However, Due To The Post-depositional Loss Of Nitrate In Snow, This Information May Be Erased Or Significantly Modified By Physical Or Photochemical Processes Before Preservation In Ice. We Investigated The Role Of Solar Uv Photolysis In The Post-depositional Modification Of Nitrate Mass And Stable Isotope Ratios At Dome C, Antarctica, During The Austral Summer Of 2011/2012. Two 30 Cm Snow Pits Were Filled With Homogenized Drifted Snow From The Vicinity Of The Base. One Of These Pits Was Covered With A Plexiglass Plate That Transmits Solar Uv Radiation, While The Other Was Covered With A Different Plexiglass Plate Having A Low Uv Transmittance. Samples Were Then Collected From Each Pit At A 2–5 Cm Depth Resolution And A 10-day Frequency. At The End Of The Season, A Comparable Nitrate Mass Loss Was Observed In Both Pits For The Top-level Samples (0–7 Cm) Attributed To Mixing With The Surrounding Snow. After Excluding Samples Impacted By The Mixing Process, We Derived An Average Apparent Nitrogen Isotopic Fractionation (15ϵapp) Of −67.8 ± 12 ‰ For The Snow Nitrate Exposed To Solar Uv Using The Nitrate Stable Isotope Ratios And Concentration Measurements. For The Control Samples In Which Solar Uv Was Blocked, An Apparent Average 15ϵapp Value Of −12.0 ± 1.7 ‰ Was Derived. This Difference Strongly Suggests That Solar Uv Photolysis Plays A Dominant Role In Driving The Isotopic Fractionation Of Nitrate In Snow. We Have Estimated A Purely Photolytic Nitrogen Isotopic Fractionation (15ϵphoto) Of −55.8 ± 12.0 ‰ From The Difference In The Derived Apparent Isotopic Fractionations Of The Two Experimental Fields, As Both Pits Were Exposed To Similar Physical Processes Except Exposure To Solar Uv. This Value Is In Close Agreement With The 15ϵphoto Value Of −47.9 ± 6.8 ‰ Derived In A Laboratory Experiment Simulated For Dome C Conditions (Berhanu Et Al., 2014). We Have Also Observed An Insensitivity Of 15ϵ With Depth In The Snowpack Under The Given Experimental Setup. This Is Due To The Uniform Attenuation Of Incoming Solar Uv By Snow, As 15ϵ Is Strongly Dependent On The Spectral Distribution Of The Incoming Light Flux. Together With Earlier Work, The Results Presented Here Represent A Strong Body Of Evidence That Solar Uv Photolysis Is The Most Relevant Post-depositional Process Modifying The Stable Isotope Ratios Of Snow Nitrate At Low-accumulation Sites, Where Many Deep Ice Cores Are Drilled. Nevertheless, Modeling The Loss Of Nitrate In Snow Is Still Required Before A Robust Interpretation Of Ice Core Records Can Be Provided.
Programme (up) 1011
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1680-7316 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8146
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Author E. Gautier, J. Savarino, J. Erbland, A. Lanciki, P. Possenti
Title Variability of sulfate signal in ice core records based on five replicate cores Type Journal
Year 2016 Publication Climate of the Past Abbreviated Journal
Volume 12 Issue 1 Pages 103-113
Keywords
Abstract Abstract. Current Volcanic Reconstructions Based On Ice Core Analysis Have Significantly Improved Over The Past Few Decades By Incorporating Multiple-core Analyses With A High Temporal Resolution From Different Parts Of The Polar Regions Into A Composite Common Volcanic Eruption Record. Regional Patterns Of Volcanic Deposition Are Based On Composite Records, Built From Cores Taken At Both Poles. However, In Many Cases Only A Single Record At A Given Site Is Used For These Reconstructions. This Assumes That Transport And Regional Meteorological Patterns Are The Only Source Of The Dispersion Of The Volcanic Products. Here We Evaluate The Local-scale Variability Of A Sulfate Profile In A Low-accumulation Site (Dome C, Antarctica), In Order To Assess The Representativeness Of One Core For Such A Reconstruction. We Evaluate The Variability With Depth, Statistical Occurrence, And Sulfate Flux Deposition Variability Of Volcanic Eruptions Detected In Five Ice Cores, Drilled 1 M Apart From Each Other. Local-scale Variability, Essentially Attributed To Snow Drift And Surface Roughness At Dome C, Can Lead To A Non-exhaustive Record Of Volcanic Events When A Single Core Is Used As The Site Reference, With A Bulk Probability Of 30 % Of Missing Volcanic Events And Close To 65 % Uncertainty On One Volcanic Flux Measurement (Based On The Standard Deviation Obtained From A Five-core Comparison). Averaging N Records Reduces The Uncertainty Of The Deposited Flux Mean Significantly (By A Factor 1∕ √ N); In The Case Of Five Cores, The Uncertainty Of The Mean Flux Can Therefore Be Reduced To 29 %.
Programme (up) 1011
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Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1814-9324 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8147
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Author Q. Libois, G. Picard, J. L. France, L. Arnaud, M. Dumont, C. M. Carmagnola, M. D. King
Title Influence of grain shape on light penetration in snow Type Journal
Year 2013 Publication The Cryosphere Abbreviated Journal
Volume 7 Issue 6 Pages 1803-1818
Keywords
Abstract Abstract. The energy budget and the photochemistry of a snowpack depend greatly on the penetration of solar radiation in snow. Below the snow surface, spectral irradiance decreases exponentially with depth with a decay constant called the asymptotic flux extinction coefficient. As with the albedo of the snowpack, the asymptotic flux extinction coefficient depends on snow grain shape. While representing snow by a collection of spherical particles has been successful in the numerical computation of albedo, such a description poorly explains the decrease of irradiance in snow with depth. Here we explore the limits of the spherical representation. Under the assumption of geometric optics and weak absorption by snow, the grain shape can be simply described by two parameters: the absorption enhancement parameter B and the geometric asymmetry factor gG. Theoretical calculations show that the albedo depends on the ratio B/(1-gG) and the asymptotic flux extinction coefficient depends on the product B(1-gG). To understand the influence of grain shape, the values of B and gG are calculated for a variety of simple geometric shapes using ray tracing simulations. The results show that B and (1-gG) generally covary so that the asymptotic flux extinction coefficient exhibits larger sensitivity to the grain shape than albedo. In particular it is found that spherical grains propagate light deeper than any other investigated shape. In a second step, we developed a method to estimate B from optical measurements in snow. A multi-layer, two-stream, radiative transfer model, with explicit grain shape dependence, is used to retrieve values of the B parameter of snow by comparing the model to joint measurements of reflectance and irradiance profiles. Such measurements were performed in Antarctica and in the Alps yielding estimates of B between 0.8 and 2.0. In addition, values of B were estimated from various measurements found in the literature, leading to a wider range of values (1.0–9.9) which may be partially explained by the limited accuracy of the data. This work highlights the large variety of snow microstructure and experimentally demonstrates that spherical grains, with B = 1.25, are inappropriate to model irradiance profiles in snow, an important result that should be considered in further studies dedicated to subsurface absorption of short-wave radiation and snow photochemistry.
Programme (up) 1011,1013
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Corporate Author Thesis Bachelor's thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1994-0416 ISBN Medium
Area Expedition Conference
Notes Approved yes
Call Number Serial 8148
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