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Hezel P J, Alexander B, Bitz C M, Steig E J, Holmes C D, Yang X, Sciare J, . (2011). Modeled methanesulfonic acid (MSA) deposition in Antarctica and its relationship to sea ice
. Journal of Geophysical Research: Atmospheres, 116(D23), D23214–.
Abstract: Methanesulfonic acid (MSA) has previously been measured in ice cores in Antarctica as a proxy for sea ice extent and Southern Hemisphere circulation. In a series of chemical transport model (GEOS-Chem) sensitivity experiments, we identify mechanisms that control the MSA concentrations recorded in ice cores. Sea ice is linked to MSA via dimethylsulfide (DMS), which is produced biologically in the surface ocean and known to be particularly concentrated in the sea ice zone. Given existing ocean surface DMS concentration data sets, the model does not demonstrate a strong relationship between sea ice and MSA deposition in Antarctica. The variability of DMS emissions associated with sea ice extent is small (1130%) due to the small interannual variability of sea ice extent. Wind plays a role in the variability in DMS emissions, but its contribution relative to that of sea ice is strongly dependent on the assumed DMS concentrations in the sea ice zone. Atmospheric sulfur emitted as DMS from the sea ice undergoes net transport northward. Our model runs suggest that DMS emissions from the sea ice zone may account for 2662% of MSA deposition at the Antarctic coast and 3695% in inland Antarctica. Though our results are sensitive to model assumptions, it is clear that an improved understanding of both DMS concentrations and emissions from the sea ice zone are required to better assess the impact of sea ice variability on MSA deposition to Antarctica.
Keywords: DMS, MSA, dimethylsulfide, ice core, methanesulfonic acid, sea ice, 0368 Troposphere: constituent transport and chemistry, 0750 Sea ice, 0793 Biogeochemistry, 3344 Paleoclimatology,
Programme: 414
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Bousquet, P.; Ciais, P.; Peylin, P.; Ramonet, M.; Monfray, P. (1999). Inverse modeling of annual atmospheric CO2 sources and sinks 1. Method and control inversion. J. Geophys. Res., 104(d21).
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Beine H.J., Honrath R.E., Domine F., Simpson W.R. & Fuentes J.D. (2002). NOx during background and ozone depletion periods at Alert: Fluxes above the snow surface. J. Geophys. Res., 107(d21), 4584.
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Gros V., Poisson N., Martin D., Kanakidou M. & Bonsang B. (1998). Observations and modelling of the seasonal variation of surface ozone at Amsterdam Island: 1994-1996. J. Geophys. Res., 103(d21), 28103–28109.
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Gros V, Poisson N, Martin D, Kanakidou M, Bonsang B,. (1998). J. Geophys. Res., 103(D21), 28103–28109.
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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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Baroni, Mlanie; Savarino, Jol; Cole-Dai, J.; Rai, V.K.; Thiemens, M.H. (2008). Anomalous sulfur isotope compositions of volcanic sulfate over the last millennium in Antarctic ice cores. J. Geophys. Res., 113(D20), D20112.
Abstract: The reconstruction of past volcanism from glaciological archives is based on the measurement of sulfate concentrations in ice. This method does not allow a proper evaluation of the climatic impact of an eruption owing to the uncertainty in classifying an event between stratospheric or tropospheric. This work develops a new method, using anomalous sulfur isotope composition of volcanic sulfate in order to identify stratospheric eruptions over the last millennium. The advantages and limits of this new method are established with the examination of the 10 largest volcanic signals in ice cores from Dome C and South Pole, Antarctica. Of the 10, seven are identified as stratospheric eruptions. Among them, three have been known to be stratospheric (Tambora, Kuwae, the 1259 Unknown Event) and they exhibit anomalous sulfur isotope compositions. Three unknown events (circa 1277, 1230, 1170 A.D.) and the Serua eruption have been identified as stratospheric eruptions, which suggests for the first time that they could have had significant climatic impact. However, the Kuwae and the 1259 Unknown Event stratospheric eruptions exhibit different anomalous sulfur isotope compositions between South Pole and Dome C samples. Differences in sulfate deposition and preservation patterns between the two sites can help explain these discrepancies. This study shows that the presence of an anomalous sulfur isotope composition of volcanic sulfate in ice core indicates a stratospheric eruption, but the absence of such composition does not necessarily lead to the conclusion of a tropospheric process because of differences in the sulfate deposition on the ice sheet.
Keywords: sulfur isotope anomaly; volcanic eruption; ice cores; 0370 Atmospheric Composition and Structure: Volcanic effects; 0454 Biogeosciences: Isotopic composition and chemistry; 0473 Biogeosciences: Paleoclimatology and paleoceanography; 0724 Cryosphere: Ice cores; 1041 Geochemistry: Stable isotope geochemistry
Programme: 1011
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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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Legrand M, Preunkert S, Jourdain B, Galle H, Goutail F, Weller R, Savarino J, . (2009). Year-round record of surface ozone at coastal (Dumont d'Urville) and inland (Concordia) sites in East Antarctica
. J. Geophys. Res., 114(D20), D20306–.
Keywords: Ozone, Antarctica, 0365 Atmospheric Composition and Structure: Troposphere: composition and chemistry, 0368 Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, 0330 Atmospheric Composition and Structure: Geochemical cycles,
Programme: 414;903;904;1011
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Legrand M. & De Angelis M. (1996). Light carboxylic acids in Greenlands ice: A record of past forest fires and vegetation emissions from the boreal zone. J. Geophys. Res., 101(d2), 4129–4145.
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