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Grob M, Maggi A, Stutzmann E, . (2011). Observations of the seasonality of the Antarctic microseismic signal, and its association to sea ice variability
. Geophys. Res. Lett., 38(11), L11302–.
Keywords: microseisms, sea, seismic noise, seismology, 0750 Cryosphere: Sea ice, 7299 Seismology: General or miscellaneous, 9310 Geographic Location: Antarctica,
Programme: 133
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Priyadarshi, A.; Dominguez, G.; Savarino, J.; Thiemens, M. (2011). Cosmogenic 35S: A unique tracer to Antarctic atmospheric chemistry and the polar vortex. Geophys. Res. Lett., 38(13), L13808.
Abstract: The cosmogenic radionuclide 35S (half life ?87 d) exists in both 35SO2 gas and 35SO42? aerosol phase in the atmosphere. Cosmogenic 35S fulfils a unique niche in that it has an ideal half-life for use as a tracer of atmospheric processes, possesses a gas phase precursor and undergoes gas to particle conversion, providing a chronometer that complements other measurements of radiogenic isotopes of different half lives and chemical properties. Based on radiogenic 35S measurements and concomitant model calculations, we demonstrate that 35S is a unique tracer to understand stratospheric-tropospheric air mass transport dynamics and the atmospheric oxidation capacity on a short time scale. Reported are the first measurements of 35S contained in SO42? aerosols (bulk and size aggregated) at Antarctica. 35SO42? concentrations at Dome C and Dumont D'Urville exhibit summer maxima and winter minima with a secondary winter peak. Higher oxidative capacity of the atmosphere and long range transport of mid latitude air increases 35SO42? activity in summer whereas a lack of air mass mixing coupled with low oxidant concentration in winter significantly decreases 35SO42? activity. A 3% contribution from stratospheric 35SO42? into the free troposphere during stratosphere-troposphere air mass mixing accounts for the secondary winter 35SO42? peak. In the future, this work will be extended to 35S activity measurements of both gas and aerosol phases to further understand gas to particle conversion, vortex dynamics and trace polar stratospheric cloud sedimentation frequency.
Keywords: Antarctica; cosmogenic radionuclide; stratosphere-troposphere mixing; 3307 Atmospheric Processes: Boundary layer processes; 3362 Atmospheric Processes: Stratosphere/troposphere interactions; 3363 Atmospheric Processes: Stratospheric dynamics
Programme: 1011
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Favier Vincent, Agosta Ccile, Genthon Christophe, Arnaud Laurent, Trouvillez Alexandre, Galle Hubert, . (2011). Modeling the mass and surface heat budgets in a coastal blue ice area of Adelie Land, Antarctica
. 0148-0227, 116(F3), F03017–.
Abstract: Meteorological data recorded from 12 December 2008 to 30 June 2010 were analyzed to assess the surface energy balance (SEB) in a blue ice area of Cap Prudhomme, Adelie Land (6641′S, 13955′E). The SEB was computed with a newly developed model forced by direct measurements and with a voluntarily limited number of parameters to better assess model sensitivity. Incoming short-wave radiation was corrected for the slope and orientation of the local terrain assuming direct and diffuse radiation components. Turbulent heat fluxes were assessed using the bulk aerodynamic approach. Heat conduction in the ice was computed by solving the thermal diffusion equation. Snow accumulation was modeled using ERA interim total precipitation and a one-dimensional erosion model. The surface heat budget and accumulation/erosion model accurately reproduced field observations. The occurrence of blue ice is linked with higher rates of erosion than in the surrounding snow covered areas, which may be caused by local flow divergence or snow not being redistributed from higher elevations. Melting occurs between December and February when incoming short-wave radiation is high. However, the SEB was closely linked to air temperature through the incoming long-wave radiation and the turbulent sensible heat flux. Several warm events caused by cyclones intruding into the continent led to significant warming of the ice and high melting rates. Intruding cyclones were also associated with high precipitation that led to significant accumulation. Except in blue ice areas, modeling suggests that expected higher precipitation in a warmer climate will result in more accumulation.
Keywords: Antarctica, blue ice, cryosphere, energy balance, melting, 0738 Cryosphere: Ice (1863), 0762 Cryosphere: Mass balance (1218, 1223), 0764 Cryosphere: Energy balance, 0768 Cryosphere: Thermal regime, 0798 Cryosphere: Modeling (1952, 4316),
Programme: 411;1013
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Bousquet P, Yver C, Pison I, Li Y S, Fortems A, Hauglustaine D, Szopa S, Rayner P J, Novelli P, Langenfelds R, Steele P, Ramonet M, Schmidt M, Foster P, Morfopoulos C, Ciais P, . (2011). A three-dimensional synthesis inversion of the molecular hydrogen cycle: Sources and sinks budget and implications for the soil uptake
. J. Geophys. Res., 116(D1), D01302–.
Keywords: atmospheric inversion, molecular hydrogen, sources and sinks, H2 budget, H2 soil uptake, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 0414 Biogeosciences: Biogeochemical cycles, processes, and modeling, 0489 Biogeosciences: Trace element cycling,
Programme: 416
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Chevallier F, Ciais P, Conway T J, Aalto T, Anderson B E, Bousquet P, Brunke E G, Ciattaglia L, Esaki Y, Frhlich M, Gomez A, Gomez-Pelaez A J, Haszpra L, Krummel P B, Langenfelds R L, Leuenberger M, Machida T, Maignan F, Matsueda H, Morgu J A, Mukai H, Nakazawa T, Peylin P, Ramonet M, Rivier L, Sawa Y, Schmidt M, Steele L P, Vay S A, Vermeulen A T, Wofsy S, Worthy D, . (2010). CO2 surface fluxes at grid point scale estimated from a global 21 year reanalysis of atmospheric measurements
. J. Geophys. Res., 115(D21), D21307–.
Keywords: CO2, flux inversion, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0428 Biogeosciences: Carbon cycling, 3315 Atmospheric Processes: Data assimilation, 3260 Mathematical Geophysics: Inverse theory,
Programme: 416
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. (2011). Internal waves and vertical mixing in the Storfjorden Polynya, Svalbard
. Journal of Geophysical Research: Oceans, 116(C12), C12040–.
Keywords: Garret and Munk model, Thorpe scale, barotropic tides, internal waves, latent heat polynya, vertical mixing, 4207 Arctic and Antarctic oceanography, 4544 Internal and inertial waves, 4572 Upper ocean and mixed layer processes,
Programme: 1015
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Houssais Marie-Nolle, Herbaut Christophe, . (2011). Atmospheric forcing on the Canadian Arctic Archipelago freshwater outflow and implications for the Labrador Sea variability
. 0148-0227, 116, C00D02–.
Keywords: Arctic Ocean, freshwater, North Atlantic Oscillation, 4207 Oceanography: General: Arctic and Antarctic oceanography, 4215 Oceanography: General: Climate and interannual variability, 4255 Oceanography: General: Numerical modeling,
Programme: 452
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. (2009). AIRS-based versus flask-based estimation of carbon surface fluxes. J. Geophys. Res., 114(D20), D20303–.
Abstract: This paper demonstrates an inversion of surface CO2 fluxes using concentrations derived from assimilation of satellite radiances. Radiances come from the Atmospheric Infrared Sounder (AIRS) and are assimilated within the system of the European Centre for Medium-Range Weather Forecasts. We evaluate the quality of the inverted fluxes by comparing simulated concentrations with independent airborne measurements. As a benchmark we use an inversion based on surface flask measurements and another using only the global concentration trend. We show that the AIRS-based inversion is able to improve the match to the independent data compared to the prior estimate but that it usually performs worse than either the flask-based or trend-based inversion.
Keywords: CO 2 surface fluxes, inverse method, AIRS satellite data, 0322 Atmospheric Composition and Structure: Constituent sources and sinks, 0428 Biogeosciences: Carbon cycling, 0480 Biogeosciences: Remote sensing, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 3315 Atmospheric Processes: Data assimilation,
Programme: 416
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Sciare J, Favez O, Sarda-Estve R, Oikonomou K, Cachier H, Kazan V, . (2009). Long-term observations of carbonaceous aerosols in the Austral Ocean atmosphere: Evidence of a biogenic marine organic source
. J. Geophys. Res., 114(D15), D15302–.
Keywords: organic aerosols, black carbon, biogenic aerosols, Austral Ocean, chlorophyll a, 0305 Atmospheric Composition and Structure: Aerosols and particles, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 3339 Atmospheric Processes: Ocean/atmosphere interactions,
Programme: 414;415;416
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Schlichtholz P, Houssais M-N, . (2011). Forcing of oceanic heat anomalies by air-sea interactions in the Nordic Seas area
. 0148-0227, 116(C1), C01006–.
Abstract: Hydrographic data and atmospheric reanalysis from 1982 to 2005 are used to show a strong link of the Atlantic water temperature (AWT) anomalies observed in the transition zone between the Norwegian Atlantic current and the West Spitsbergen current in summer to the surface heat flux (SHF) anomalies observed over the Barents Sea open water in the preceding late winter. A mechanism proposed for this link is formation of ocean temperature anomalies in a deep mixed layer and their subsequent westward export by a branch of Atlantic water recirculating in the western Barents Sea. The SHF anomalies over the Barents Sea are due to advection of temperature and humidity by anomalous winds across the Arctic ice edge and do not strongly depend on the North Atlantic oscillation (NAO). Correlations of up to about 0.9 between the AWT anomalies and indices of atmospheric variability over the Barents Sea open prospects for seasonal AWT predictability. It is also shown that the wind-forcing responsible for positive AWT anomalies is involved in a cyclonic perturbation of the atmospheric circulation over the Nordic Seas. This perturbation generates, through influence on the sea ice distribution, a lobe of SHF anomalies in the marginal ice zone (MIZ) on the eastern (Barents Sea) and western (Greenland Sea) sides of the Nordic Seas which has the opposite sign to the open water lobe. In contrast to the Barents Sea MIZ, the diabatic heating of the atmosphere by upward SHF anomalies in the Greenland Sea MIZ competes with cold advection.
Keywords: Nordic Seas, heat anomalies, air-sea interactions, interanual variability, Atlantic water, 4215 Oceanography: General: Climate and interannual variability, 4504 Oceanography: Physical: Air/sea interactions, 4207 Oceanography: General: Arctic and Antarctic oceanography, 4263 Oceanography: General: Ocean predictability and prediction, 4572 Oceanography: Physical: Upper ocean and mixed layer processes,
Programme: 452
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