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Titel |
Stochastic parameterization of dust emission and application to convective atmospheric conditions |
VerfasserIn |
M. Klose, Y. Shao |
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 ; 12, no. 16 ; Nr. 12, no. 16 (2012-08-16), S.7309-7320 |
Datensatznummer |
250011385
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Publikation (Nr.) |
copernicus.org/acp-12-7309-2012.pdf |
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Zusammenfassung |
We develop a parameterization scheme of convective dust emission for regional
and global atmospheric models. Convective dust emission occurs in the absence
of saltation as large eddies intermittently produce strong shear stresses on
the surface and entrain dust particles into the air. This dust emission
mechanism has not been included in the traditional dust models. The scheme
presented in this study is a new approach which takes account of the
stochastic nature of convective dust emission. It consists of the statistical
representations of soil particle size, inter-particle cohesion, and
instantaneous surface shear stress. A method of determining the probability
density function of the latter quantity is proposed. Dust emission is then
estimated from the overlap of the probability density functions of the
aerodynamic lifting and inter-particle cohesive forces. The new scheme is
implemented into the WRF/Chem model and applied to dust modeling in the
Taklimakan Desert. A comparison with lidar data shows that the model can
reproduce the main features of the dust patterns and their diurnal
variations. For the case studied, convective dust emission is typically
several μg m−2 s−1 and at times up to
50 μg m−2 s−1. |
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