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| Titel |
Modelling the reversible uptake of chemical species in the gas phase by ice particles formed in a convective cloud |
| VerfasserIn |
V. Marecal, M. Pirre, E. D. Rivière, N. Pouvesle, J. N. Crowley, S. R. Freitas, K. M. Longo |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 10, no. 10 ; Nr. 10, no. 10 (2010-05-31), S.4977-5000 |
| Datensatznummer |
250008490
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| Publikation (Nr.) |
 copernicus.org/acp-10-4977-2010.pdf |
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| Zusammenfassung |
| The present paper is a preliminary study preparing the introduction of
reversible trace gas uptake by ice particles into a 3-D cloud resolving
model. For this a 3-D simulation of a tropical deep convection cloud was run
with the BRAMS cloud resolving model using a two-moment bulk microphysical
parameterization. Trajectories within the convective clouds were computed
from these simulation outputs along which the variations of the pristine
ice, snow and aggregate mixing ratios and concentrations were extracted. The
reversible uptake of 11 trace gases by ice was examined assuming
applicability of Langmuir isotherms using recently evaluated (IUPAC)
laboratory data. The results show that ice uptake is only significant for
HNO3, HCl, CH3COOH and HCOOH. For H2O2, using new
results for the partition coefficient results in significant partitioning to
the ice phase for this trace gas also. It was also shown that the uptake is
largely dependent on the temperature for some species. The adsorption
saturation at the ice surface for large gas mixing ratios is generally not a
limiting factor except for HNO3 and HCl for gas mixing ratio greater
than 1 ppbv. For HNO3, results were also obtained using a trapping
theory, resulting in a similar order of magnitude of uptake, although the
two approaches are based on different assumptions. The results were compared
to those obtained using a BRAMS cloud simulation based on a single-moment
microphysical scheme instead of the two moment scheme. We found similar
results with a slightly more important uptake when using the single-moment
scheme which is related to slightly higher ice mixing ratios in this
simulation. The way to introduce these results in the 3-D cloud model is
discussed. |
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