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Titel |
An improved dust emission model – Part 1: Model description and comparison against measurements |
VerfasserIn |
J. F. Kok, N. M. Mahowald, G. Fratini, J. A. Gillies, M. Ishizuka, J. F. Leys, M. Mikami, M.-S. Park, S.-U. Park, R. S. Van Pelt, T. M. Zobeck |
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 ; 14, no. 23 ; Nr. 14, no. 23 (2014-12-09), S.13023-13041 |
Datensatznummer |
250119223
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Publikation (Nr.) |
copernicus.org/acp-14-13023-2014.pdf |
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Zusammenfassung |
Simulations of the dust cycle and its interactions with the changing Earth
system are hindered by the empirical nature of dust emission
parameterizations in weather and climate models. Here we take a step towards
improving dust cycle simulations by using a combination of theory and
numerical simulations to derive a physically based dust emission
parameterization. Our parameterization is straightforward to implement into
large-scale models, as it depends only on the wind friction velocity and the
soil's threshold friction velocity. Moreover, it accounts for two processes
missing from most existing parameterizations: a soil's increased ability to
produce dust under saltation bombardment as it becomes more erodible, and the increased scaling of the
dust flux with wind speed as a soil becomes less erodible. Our treatment of both these processes is supported by a
compilation of quality-controlled vertical dust flux measurements.
Furthermore, our scheme reproduces this measurement compilation with
substantially less error than the existing dust flux parameterizations we
were able to compare against. A critical insight from both our theory and
the measurement compilation is that dust fluxes are substantially more
sensitive to the soil's threshold friction velocity than most current
schemes account for. |
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