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Titel |
Influence of microphysical schemes on atmospheric water in the Weather Research and Forecasting model |
VerfasserIn |
F. Cossu, K. Hocke |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1991-959X
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Digitales Dokument |
URL |
Erschienen |
In: Geoscientific Model Development ; 7, no. 1 ; Nr. 7, no. 1 (2014-01-28), S.147-160 |
Datensatznummer |
250115534
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Publikation (Nr.) |
copernicus.org/gmd-7-147-2014.pdf |
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Zusammenfassung |
This study examines how different microphysical parameterization schemes
influence orographically induced precipitation and the distributions of
hydrometeors and water vapour for midlatitude summer conditions in the
Weather Research and Forecasting (WRF) model. A high-resolution
two-dimensional idealized simulation is used to assess the differences
between the schemes in which a moist air flow is interacting with a
bell-shaped 2 km high mountain. Periodic lateral boundary conditions
are chosen to recirculate atmospheric water in the domain. It is found that
the 13 selected microphysical schemes conserve the water in the model domain.
The gain or loss of water is less than 0.81% over a simulation time
interval of 61 days. The differences of the microphysical schemes in terms of
the distributions of water vapour, hydrometeors and accumulated precipitation
are presented and discussed. The Kessler scheme, the only scheme without
ice-phase processes, shows final values of cloud liquid water 14 times
greater than the other schemes. The differences among the other schemes are
not as extreme, but still they differ up to 79% in water vapour, up to 10
times in hydrometeors and up to 64% in accumulated precipitation at the
end of the simulation. The microphysical schemes also differ in the surface
evaporation rate. The WRF single-moment 3-class scheme has the highest
surface evaporation rate compensated by the highest precipitation rate. The
different distributions of hydrometeors and water vapour of the microphysical
schemes induce differences up to 49 W m−2 in the downwelling
shortwave radiation and up to 33 W m−2 in the downwelling
longwave radiation. |
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