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| Titel |
Surface Hail Simulations in a High-Resolution Regional Climate Model |
| VerfasserIn |
Cecille Villanueva-Birriel, Kwinten Van Weverberg, Maryna Lukach, Philippe Marbaix, Jean-Pascal van Ypersele |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110853
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| Publikation (Nr.) |
 EGU/EGU2015-10893.pdf |
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| Zusammenfassung |
| The past years have seen a rapid advancement in computational resources, enabling regional
climate models to perform at convection-permitting resolutions. This feature has allowed the
use of complex bulk microphysical parameterizations as a means to improve cloud and
precipitation representations within these models. Given the increased trend in the last
decades of extreme precipitation events in numerous regions around the world, developments
and evaluation of microphysical parameterizations implemented in regional climate models
are crucial in order to better assess future precipitation projections. One important aspect for
accurate deep convective storm simulations is in the hail parameterization within
models, which can substantially impact precipitation and dynamical features within
the cloud along with subsequent cold pool-driven secondary convection. Great
economic costs and hazardous implications have been associated with hailstorms,
which makes it of the utmost importance to properly simulate hailstone sizes at the
surface. And yet many models have so far struggled to reproduce characteristic
observational features of hail producing storms linked to weaknesses within microphysical
parameterizations.
As part of the aims for the Modeling Atmospheric Composition and Climate for the Belgian Territory
(MACCBET) project1,
we used the COSMO-CLM model, a nonhydrostatic regional climate model, driven by
ERA-Interim data to simulate, at high resolution (3km), a selected number of intense
convective cases in the 2000-2014 period with more than half having surface hail reports. A
modified version of the 2-moment Seifert and Beheng (2006; Van Weverberg et al. 2014)
microphysical scheme, with an added hail category, was used for this study. Preliminary
results showed that the 2-moment scheme produced significant simulated hail as opposed to
negligible amounts present in the model runs with a 1-moment version of the same
parameterization. Additionally, the 2-moment version using gamma (2M-GAM) size
distributions for the precipitating hydrometeors showed better agreement with radar
observations compared to the simulations with particle size distributions represented as
negative exponential distributions (2M-EXP). The 2M-EXP generally showed larger areas of
hail reaching the surface together with greater hailstone sizes in comparison to the 2M-GAM
and radar observations. The causes and implications of these results will be further
discussed.
References
Seifert, A., & Beheng, K. D. (2006). A two-moment cloud microphysics parameterization
for mixed-phase clouds. Part 1: Model description. Meteorol Atmos Phys 92, 45-66.
Van Weverberg, K., Goudenhoofdt, E., Blahak, U., Brisson, E., Demuzere, M., Marbaix,
P., & van Ypersele, J. P. (2014). Comparison of one-moment and two-moment bulk
microphysics for high-resolution climate simulations of intense precipitation. Atmospheric
Research, 147, 145-161. |
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