Browsing by Author "Sartorius, H"

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    Comparison of one- and two-filter detectors for atmospheric 222Rn measurements under various meteorological conditions
    (European Geosciences Union, 2010-06-28) Xia, Y; Sartorius, H; Schlosser, C; Stohlker, U; Conen, F; Zahorowski, W
    Parallel monitoring of 222Rn and its short-lived progeny (218Po and 214Pb) were carried out from November 2007 to April 2008 close to the top of the Schauinsland mountain, partly covered with forest, in South-West Germany. Samples were aspired from the same location at 2.5 m above ground level. We measured 222Rn with a dual flow loop, two-filter detector and its short-lived progeny with a one-filter detector. A reference sector for events, facing a steep valley and dominated by pasture, was used to minimize differences between 222Rn and progeny-derived 222Rn activity concentrations. In the two major wind sectors covered by forest to a distance between 60 m and 80 m towards the station progeny-derived 222Rn activity concentration was on average equal to 87% (without precipitation) and 74% (with precipitation) of 222Rn activity concentration. The observations show that most of the time both detector types follow the same pattern. Still, there is no single disequilibrium factor that could be used to exactly transform short-lived progeny to 222Rn activity concentration under all meteorological conditions. © Author(s) 2010
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    Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions
    (European Geosciences Union, 2011-01-01) Zhang, K; Feichter, J; Kazil, J; Wan, H; Zhuo, W; Griffiths, AD; Sartorius, H; Zahorowski, W; Ramonet, M; Schmidt, M; Yver, C; Neubert, REM; Brunke, EG
    The radioactive decay of radon and its progeny can lead to ionization of air molecules and consequently influence aerosol size distribution. In order to provide a global estimate of the radon-related ionization rate, we use the global atmospheric model ECHAM5 to simulate transport and decay processes of the radioactive tracers. A global radon emission map is put together using regional fluxes reported recently in the literature. Near-surface radon concentrations simulated with this new map compare well with measurements. Radon-related ionization rate is calculated and compared to that caused by cosmic rays. The contribution of radon and its progeny clearly exceeds that of the cosmic rays in the mid- and low-latitude land areas in the surface layer. During cold seasons, at locations where high concentration of sulfuric acid gas and low temperature provide potentially favorable conditions for nucleation, the coexistence of high ionization rate may help enhance the particle formation processes. This suggests that it is probably worth investigating the impact of radon-induced ionization on aerosol-climate interaction in global models. © Author(s) 2011.
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    TransCom continuous experiments: comparison of radon concentrations at inland stations
    (Global Carbon Project, 2008-06) Taguchi, S; Law, RM; Peters, W; Rodenbeck, C; Patra, PK; Maksyutov, S; Zahorowski, W; Sartorius, H; Levin, I