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| Titel |
Simulating deep convection with a shallow convection scheme |
| VerfasserIn |
C. Hohenegger, C. S. Bretherton |
| 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 ; 11, no. 20 ; Nr. 11, no. 20 (2011-10-19), S.10389-10406 |
| Datensatznummer |
250010133
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| Publikation (Nr.) |
 copernicus.org/acp-11-10389-2011.pdf |
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| Zusammenfassung |
Convective processes profoundly affect the global water and energy balance of
our planet but remain a challenge for global climate modeling. Here we
develop and investigate the suitability of a unified convection scheme,
capable of handling both shallow and deep convection, to simulate cases of
tropical oceanic convection, mid-latitude continental convection, and
maritime shallow convection. To that aim, we employ large-eddy simulations
(LES) as a benchmark to test and refine a unified convection scheme
implemented in the Single-column Community Atmosphere Model (SCAM). Our
approach is motivated by previous cloud-resolving modeling studies, which
have documented the gradual transition between shallow and deep convection
and its possible importance for the simulated precipitation diurnal cycle.
Analysis of the LES reveals that differences between shallow and deep
convection, regarding cloud-base properties as well as
entrainment/detrainment rates, can be related to the evaporation of
precipitation. Parameterizing such effects and accordingly modifying the
University of Washington shallow convection scheme, it is found that the new
unified scheme can represent both shallow and deep convection as well as
tropical and mid-latitude continental convection. Compared to the default
SCAM version, the new scheme especially improves relative humidity, cloud
cover and mass flux profiles. The new unified scheme also removes the
well-known too early onset and peak of convective precipitation over
mid-latitude continental areas. |
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