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Shaheen R, Abaunza M M, Jackson T L, McCabe J, Savarino J, Thiemens M H, . (2014). Large sulfur-isotope anomaly in nonvolcanic sulfate aerosol and its implications for the Archean atmosphere
. 0027-8424, 111(33), 11979–11983.
Abstract: Sulfur-isotopic anomalies have been used to trace the evolution of oxygen in the Precambrian atmosphere and to document past volcanic eruptions. High-precision sulfur quadruple isotope measurements of sulfate aerosols extracted from a snow pit at the South Pole (1984-2001) showed the highest S-isotopic anomalies ({Delta}33S = +1.66{per thousand} and {Delta}36S = +2{per thousand}) in a nonvolcanic (1998-1999) period, similar in magnitude to Pinatubo and Agung, the largest volcanic eruptions of the 20th century. The highest isotopic anomaly may be produced from a combination of different stratospheric sources (sulfur dioxide and carbonyl sulfide) via SOx photochemistry, including photoexcitation and photodissociation. The source of anomaly is linked to super El Nino Southern Oscillation (ENSO) (1997-1998)-induced changes in troposphere-stratosphere chemistry and dynamics. The data possess recurring negative S-isotope anomalies ({Delta}36S = -0.6 {+/-} 0.2{per thousand}) in nonvolcanic and non-ENSO years, thus requiring a second source that may be tropospheric. The generation of nonvolcanic S-isotopic anomalies in an oxidizing atmosphere has implications for interpreting Archean sulfur deposits used to determine the redox state of the paleoatmosphere.
Programme: 1011
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Legrand M, Preunkert S, Frey M, Bartels-Rausch Th, Kukui A, King M D, Savarino J, Kerbrat M, Jourdain B, . (2014). Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?
. 1680-7316, 14(18), 9963–9976.
Abstract: During the austral summer 2011/2012 atmospheric nitrous acid (HONO) was investigated for the second
time at the Concordia site (75060 S, 123330 E), located on the East Antarctic Plateau, by deploying a long-path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35±5.0 pptv) were similar to those measured in December 2010/January
2011 (30.4±3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation of
NO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gasphase HONO at mixing ratios half that of the NOx mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NOx from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8×109 molecules cm-2 s-1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation, these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO4 had biased the measurements of HONO.
Programme: 1011
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Fort J, Grémillet D, Robertson GJ, Mosbech A, Moe B, Bustamante P
. (2014). Spatial ecotoxicology: How do nonbreeding distribution of migratory Arctic seabirds affect their Hg seasonal contamination?.
Abstract: Invited talk
Arctic Change 2014 International Conference, Ottawa, Dec. 2014
Programme: 388
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Bost, C.A., Scheffer, A., Perron, C., Barbraud, C., Jenouvrier, S., Terray, P., Cotte, C. (2014). Penguins and climatic variability: foraging responses of King penguins in the South Indian Ocean. Conférencier invité. International Argos User’s Conference on Wildlife Applications, National Aquarium, Baltimore, USA, 18-20 Novembre, 2014..
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Scheffer, A. Bost, C.A., Lascelles B., Trathan, P., Ratcliffe, N. (2014). Foraging areas of macaroni penguins in the south atlantic and south Indian ocean. 5th International Bio-Logging Science Symposium, 22-27 Septembre 2014, Strasbourg..
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M. Sacchettini and E. Le Meur
. (2014). Transmission de données GPS par réseau de radio-modem en Antarctique,
Atelier Expérimentation et Instrumentation
Toulouse France12-13 novembre 2014
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COLLIGNON B. (2014). Savoirs vernaculaires et objets intermédiaires : de l’usage des photographies inuit, Séminaire de recherche de l’ENSAP-Bordeaux, Bordeaux, 8 juillet.
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COLLIGNON B. (2014). Les langages non verbaux pour penser l’espace habité inuit, Ecole doctorale de Suisse occidentale (CUSO), Rolle, 20-23 janvier. .
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COLLIGNON B. (2014). Surviving or living a good life? A critical approach of the concept of survival – Session at ICASS 8 (8th International Conference of Arctic Social Sciences), Université de Colombie britannique, Prince George (Canada), 22-26 mai 2014..
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COLLIGNON B. (2014). 21st Century Inuit Ordinary Mobility – first results from an exploratory survey, in ICASS 8 (8th International Conference of Arctic Social Sciences), Université de Colombie britannique, Prince George (Canada), 22-26 mai 2014..
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