|
|
Song S, Selin N E, Soerensen A L, Angot H, Artz R, Brooks S, Brunke E-G, Conley G, Dommergue A, Ebinghaus R, Holsen T M, Jaffe D A, Kang S, Kelley P, Luke W T, Magand O, Marumoto K, Pfaffhuber K A, Ren X, Sheu G-R, Slemr F, Warneke T, Weigelt A, Weiss-Penzias P, Wip D C, Zhang Q, . (2015). Top-down constraints on atmospheric mercury emissions and implications for global biogeochemical cycling
. Atmospheric Chemistry and Physics, 15(12), 7103–7125.
|
|
|
|
Dommergue, A., Angot, H., and Magand, O. (2015). Recent measurements of atmospheric mercury in the Southern Hemisphere and their contribution to the understanding of Hg cycle.
|
|
|
|
Angot, H., Dommergue, A., Magand, O., Helmig, D., Pirrone, N., and Sprovieri, F.:. (2015). Year-round record of gaseous mercury in air and snow: new insights into mercury reactivity in Central Antarctica (Dome C.
|
|
|
|
Sprovieri, F., Pirrone, N., Bencardino, M., D'Amore, F., Angot, H., Barbante, C., Brunke, E.G., Arcega-Cabrera, F., Cairns, W., Comero, S., Diéguez, M.D.C., Dommergue, A., Ebinghaus, R., Feng, X.B., Fu, X., Garcia, P.E., Gawlik, B.M., Hageström, U., Hansson, K., Horvat, M., Kotnik, J., Labuschagne, C., Magand, O., Martin, L., Mashyanov, N., Mkololo, T., Munthe, J., Obolkin, V., Islas, M.R., Sena, F., Somerset, V., Spandow, P., Vardè, M., Walters, C., Wängberg, I., Weigelt, A., Yang, X., Zhang, H.. (2016). Five-year records of Total Mercury Deposition flux at GMOS sites in the Northern and Southern Hemispheres.. Atmos. chem. phys., 17(4), 2689–2708.
|
|
|
|
Pearce, D.A., Alekhina, I.A., Terauds, A., Wilmotte, A., Quesada, A., Edwards, A., Dommergue, A., Sattler, B., Adams, B., Magalhães, C.M., Chu, W.-L., Lau, M., Cary, S.C., Smith, D.J., Wall, D.H., Eguren, G., Matcher, G., Bradley, J., De Vera, J.-P.P., Elster, J., Hughes, K.A., Benning, L.G., Gunde - Cimerman, N., Convey, P., Hong, S.G., Pointing, S.B., Pellizari, V.H., Vincent, W.F., 2016. . (2016). Aerobiology over Antarctica – a new initiative for atmospheric ecology. 1664-302X, 7.
Abstract: The role of aerial dispersal in shaping patterns of biodiversity remains poorly understood, mainly due to a lack of coordinated efforts in gathering data at appropriate temporal and spatial scales. It has been long known that the rate of dispersal to an ecosystem can significantly influence ecosystem dynamics, and that aerial transport has been identified as an important source of biological input to remote locations. With the considerable effort devoted in recent decades to understanding atmospheric circulation in the south polar region, a unique opportunity has emerged to investigate the atmospheric ecology of Antarctica, from local to continental scales. This concept note identifies key questions in Antarctic microbial biogeography and the need for standardized sampling and analysis protocols to address such questions. A consortium of polar aerobiologists is established to bring together researchers with a common interest in the airborne dispersion of microbes and other propagules in the Antarctic, with opportunities for comparative studies in the Arctic.
Programme: 1028
|
|
|
|
Nerentorp Mastromonaco, M., Gårdfeldt, K., Jourdain, B., Abrahamsson, K., Granfors, A., Ahnoff, M., Dommergue, A., Méjean, G., Jacobi, H.W. . (2016). Antarctic winter mercury and ozone depletion events over sea ice.. Atmospheric environment, 129, 125–132.
Abstract: During atmospheric mercury and ozone depletion events in the springtime in polar regions gaseous elemental mercury and ozone undergo rapid declines. Mercury is quickly transformed into oxidation products, which are subsequently removed by deposition. Here we show that such events also occur during Antarctic winter over sea ice areas, leading to additional deposition of mercury. Over four months in the Weddell Sea we measured gaseous elemental, oxidized, and particulate-bound mercury, as well as ozone in the troposphere and total and elemental mercury concentrations in snow, demonstrating a series of depletion and deposition events between July and September. The winter depletions in July were characterized by stronger correlations between mercury and ozone and larger formation of particulate-bound mercury in air compared to later spring events. It appears that light at large solar zenith angles is sufficient to initiate the photolytic formation of halogen radicals. We also propose a dark mechanism that could explain observed events in air masses coming from dark regions. Br2 that could be the main actor in dark conditions was possibly formed in high concentrations in the marine boundary layer in the dark. These high concentrations may also have caused the formation of high concentrations of CHBr3 and CH2I2 in the top layers of the Antarctic sea ice observed during winter. These new findings show that the extent of depletion events is larger than previously believed and that winter depletions result in additional deposition of mercury that could be transferred to marine and terrestrial ecosystems.
Programme: 1028
|
|
|
|
Angot, H., Magand, O., Helmig, D., Ricaud, P., Quennehen, B., Gallée, H., Del Guasta, M., Sprovieri, F., Pirrone, N., Savarino, J., Dommergue, A.. (2016). New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale. Atmospheric chemistry and physics, 16(13), 8249–8264.
Abstract: Under the framework of the GMOS project (Global Mercury Observation System) atmospheric mercury monitoring has been implemented at Concordia Station on the high-altitude Antarctic plateau (75°06′ S, 123°20′ E, 3220 m above sea level). We report here the first year-round measurements of gaseous elemental mercury (Hg(0)) in the atmosphere and in snowpack interstitial air on the East Antarctic ice sheet. This unique data set shows evidence of an intense oxidation of atmospheric Hg(0) in summer (24-hour daylight) due to the high oxidative capacity of the Antarctic plateau atmosphere in this period of the year. Summertime Hg(0) concentrations exhibited a pronounced daily cycle in ambient air with maximal concentrations around midday. Photochemical reactions and chemical exchange at the air–snow interface were prominent, highlighting the role of the snowpack on the atmospheric mercury cycle. Our observations reveal a 20 to 30 % decrease of atmospheric Hg(0) concentrations from May to mid-August (winter, 24 h darkness). This phenomenon has not been reported elsewhere and possibly results from the dry deposition of Hg(0) onto the snowpack. We also reveal the occurrence of multi-day to weeklong atmospheric Hg(0) depletion events in summer, not associated with depletions of ozone, and likely due to a stagnation of air masses above the plateau triggering an accumulation of oxidants within the shallow boundary layer. Our observations suggest that the inland atmospheric reservoir is depleted in Hg(0) in summer. Due to katabatic winds flowing out from the Antarctic plateau down the steep vertical drops along the coast and according to observations at coastal Antarctic stations, the striking reactivity observed on the plateau most likely influences the cycle of atmospheric mercury on a continental scale.
Programme: 1028
|
|
|
|
Angot, H., Dion, I., Vogel, N., Legrand, M., Magand, O., Dommergue, A.. (2016). Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences. 1680-7316, 16(13), 8265–8279.
Abstract: Under the framework of the Global Mercury Observation System (GMOS) project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0)) has been gathered at Dumont d'Urville (DDU, 66°40′ S, 140°01′ E, 43 m above sea level) on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0) at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1) as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0) concentrations. The open ocean may represent a source of atmospheric Hg(0) in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0). This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.
Programme: 1028
|
|
|
|
. (2017). Five-year records of mercury wet deposition flux at GMOS sites in the Northern and Southern hemispheres (Vol. 17).
|
|
|
|
. (2017). Multi-model study of mercury dispersion in the atmosphere: atmospheric processes and model evaluation (Vol. 17).
|
|
