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Jourdain, B.; Legrand, M. (2002). Year-round records of bulk and size-segregated aerosol composition and HCl and HNO3 levels in the Dumont d'Urville (coastal Antarctica) atmosphere: Implications for sea-salt aerosol fractionation in the winter and summer. J. Geophys. Res., 107.
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. (2007). Diurnal production of gaseous mercury in the alpine snowpack before snowmelt. J. Geophys. Res., 112.
Keywords: Gaesous mercury; snow; flux; 0330 Atmospheric Composition and Structure: Geochemical cycles; 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 1863 Hydrology: Snow and ice
Programme: 399
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Mahowald, N.M.; Rasch, P.J.; Eaton, B.E.; Whittlestone, S.; Prinn, R.G. (). Transport of 222radon to the remote troposphere using the Model of Atmospheric Transport and Chemistry and assimilated winds from ECMWF and the National Center for Environmental Prediction/NCAR. J. Geophys. Res., 102.
Abstract: The Model of Atmospheric Transport and Chemistry (MATCH) is used to simulate the transport of 222Rn using both European Centre for Medium-Range Weather Forecasts (ECMWF) winds and National Center for Environmental Prediction/National Center for Atmospheric Research (hereafter referred to as NCEP) reanalysis winds. These winds have the advantage of being based on observed winds but have the disadvantage that the subgrid-scale transport processes are not routinely archived. MATCH derives subgrid-scale mixing rates for the boundary layer using a nonlocal scheme and for moist convective mixing using one of two parameterizations (Tiedtke [1989] or Pan and Wu [1997]). This paper describes the ability of the model to recreate mixing rates of 222Rn using the forecast center winds. Radon 222 is a species with a continental crust source and a simple sink involving radioactive decay with an e-folding timescale of 5.5 days. This atmospheric constituent is therefore a good tracer for testing the vertical transport in the chemical transport model, as well as the horizontal transport from continental regions to remote oceanic regions. The various simulations of 222Rn are compared with observations as well as with each other, allowing an estimate of the uncertainty in transport due to uncertainties in the winds and subgrid-scale processes. The calculated vertical profiles over the western United States are somewhat similar to observed, and the upper tropospheric concentrations compare reasonably well in their spatial distribution with data collected during Tropospheric Ozone II (TROPOZ II), although the model values tend to be higher than observed values, especially in the upper troposphere. The model successfully simulates specific observed pollution events at Cape Grim. It has more difficulty at sites farther from continental source regions, although the model captures the seasonal structure of the pollution events at these sites (Macquarie Island, Amsterdam Island, Kerguelen Island, and Crozet Island). Inclusion of a moist convective mixing scheme in MATCH increases 222Rn concentrations in the upper troposphere by 50% compared to not having moist convective mixing, while surface concentrations do not appear to be very sensitive to moist convection. In addition, differences between the upper tropospheric concentrations of radon predicted using the ECMWF and NCEP winds can be 30% for large areas of the globe, due to either differences in the forecast center winds themselves or the moist convective mixing schemes used in conjunction with them. This has implications for model simulations of radiatively and chemically important trace species in the atmosphere.
Programme: 146
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. (2002). Dust and sea salt variability in central East Antarctica (Dome C) over the last 45 kyrs and its implications for southern high-latitude climate. Geophysical research letters, 29.
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McCabe, J.R.; Thiemens, M.H.; Savarino, J. (2007). A record of ozone variability in South Pole Antarctic snow: Role of nitrate oxygen isotopes. J. Geophys. Res., 112.
Keywords: nitrate; isotopes; ozone; 1041 Geochemistry: Stable isotope geochemistry; 0305 Atmospheric Composition and Structure: Aerosols and particles; 3344 Atmospheric Processes: Paleoclimatology; 1610 Global Change: Atmosphere; 0776 Cryosphere: Glaciology
Programme: 1011
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Yagova, N.V.; Pilipenko, V.A.; Lanzerotti, L.J.; Engebretson, M.J.; Rodger, A.S.; Lepidi, S.; Papitashvili, V.O. (2004). Two-dimensional structure of long-period pulsations at polar latitudes in Antarctica. J. Geophys. Res., 109.
Abstract: Two-dimensional (2-D) statistical distributions of spectral power and coherence of polar geomagnetic variations with quasi-periods about 10 min are analyzed using data from magnetometer arrays in Antarctica. Examination of the 2-D patterns of spectral power and coherence shows the occurrence of significant variations in geomagnetic power levels but with low spatial coherence near the cusp projection and in the auroral region. At the same time, low-amplitude pulsations, which we coin Pi cap
3 pulsations, are very coherent throughout the polar cap. The region occupied by coherent Pi cap
3 pulsations is shifted toward local MLT night from the geomagnetic pole and is decoupled from the regions of auroral and cusp ULF activity. The spectral power varies with time at polar latitudes in a manner different from that at auroral latitudes. Diurnal variations of power at different stations at the same geomagnetic latitude exhibit different behavior depending on the station's position relative to geomagnetic and geographic poles. This asymmetry is shown to be partly attributed to the variations of the ionospheric conductance. The primary source of polar pulsations is probably related to intermittent magnetosheath turbulence and tail lobe oscillations, though a particular propagation mechanism has not as yet been identified.
Keywords: 2776 Magnetospheric Physics: Polar cap phenomena; 2752 Magnetospheric Physics: MHD waves and instabilities; 2744 Magnetospheric Physics: Magnetotail; 2724 Magnetospheric Physics: Magnetopause, cusp, and boundary layers
Programme: 905
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De Lauretis, M.; Francia, P.; Vellante, M.; Piancatelli, A.; Villante, U.; Di Memmo, D. (2005). ULF geomagnetic pulsations in the southern polar cap: Simultaneous measurements near the cusp and the geomagnetic pole. J. Geophys. Res., 110.
Keywords: polar cap phenomena; cusp; MHD waves and turbulence; solar wind/magnetosphere interactions; 2776 Magnetospheric Physics: Polar cap phenomena; 2706 Magnetospheric Physics: Cusp; 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions; 2752 Magnetospheric Physics: MHD waves and instabilities; 2740 Magnetospheric Physics: Magnetospheric configuration and dynamics
Programme: 1130
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Delmotte, M.; Chappellaz, J.; Brook, E.; Yiou, P.; Barnola, J.M.; Goujon, C.; Raynaud, D.; Lipenkov, V.I. (2004). Atmospheric methane during the last four glacial-interglacial cycles: Rapid changes and their link with Antarctic temperature. J. Geophys. Res., 109.
Keywords: climate; atmospheric methane; ice core; 0325 Atmospheric Composition and Structure: Evolution of the atmosphere; 1610 Global Change: Atmosphere; 1615 Global Change: Biogeochemical processes; 3339 Meteorology and Atmospheric Dynamics: Ocean/atmosphere interactions
Programme: 439;902
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Merrer, S.; Cara, M.; Rivera, L.; Ritsema, J. (2007). Upper mantle structure beneath continents: New constraints from multi-mode Rayleigh wave data in western North America and southern Africa. Geophysical research letters, 34.
Keywords: Rayleigh waves; upper mantle; 7208 Seismology: Mantle; 7255 Seismology: Surface waves and free oscillations; 7290 Seismology: Computational seismology
Programme: 133;906
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. (2008). Equivalent ionospheric currents for the 5 December 2006 solar flare effect determined from spherical cap harmonic analysis. J. Geophys. Res., 113.
Keywords: solar flare effects; SCHA; magnetic observatories; 1530 Geomagnetism and Paleomagnetism: Rapid time variations; 2409 Ionosphere: Current systems; 2447 Ionosphere: Modeling and forecasting; 7974 Space Weather: Solar effects; 0545 Computational Geophysics: Modeling
Programme: 139
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