Simulations of an isolated two-dimensional thunderstorm : sensitivity to cloud droplet size and the presence of graupel

dc.contributor.authorBopape, Mary-Jane Morongwa
dc.contributor.authorEngelbrecht, Francois Alwyn
dc.contributor.authorRandall, David A.
dc.contributor.authorLandman, Willem Adolf
dc.date.accessioned2014-05-20T13:03:53Z
dc.date.available2014-05-20T13:03:53Z
dc.date.issued2014-02
dc.description.abstractCloud Resolving Models (CRMs) which are used increasingly to make operational forecasts, employ Bulk Microphysics Schemes (BMSs) to describe cloud microphysical processes. In this study two BMSs are employed in a new Nonhydrostatic σ-coordinate Model to perform two hour simulations of convection initiated by a warm bubble, using a horizontal grid resolution of 500 m. Different configurations of the two BMSs are applied, to test the effects of the presence of graupel with one scheme (2-configurations) and of changing the cloud droplet sizes in the second scheme (4-configurations), on the simulation of idealised thunderstorms. Maximum updrafts in all the simulations are similar over the first 40 minutes, but start to differ beyond this point. The first scheme simulates the development of a second convective cell that is triggered by the cold pool that develops from the outflow of the first storm. The cold pool is more intense in the simulation with graupel because of melting of graupel particles, which results in relatively large raindrops, decreases the temperature through latent heat absorption, causing stronger downdrafts, which all contribute to the formation of a more intense cold pool. The second scheme simulates the development of a second cell in two of its configurations, while two other configurations do not simulate the redevelopment. Two configurations that simulate the secondary redevelopment produce a slightly stronger cold pool just before redevelopment. Our results show that small differences in the microphysics formulations result in simulations of storm dynamics that diverge, possibly due nonlinearities in the model.en_US
dc.description.librarianhb2014en_US
dc.description.sponsorshipCSIR Natural Resources and the Environment for funding this work through parliamentary grant funding and Young Researcher Establishment Funds. The Centre for High Performance Computing (CHPC) in South Africa. The Applied Centre for Climate and Earth System Science (ACCESS) .en_US
dc.description.urihttp://link.springer.com/journal/13143en_US
dc.identifier.citationBopape, MJM, Engelbrecht, FA, Randall, DA & Landman, WA 2014, 'Simulations of an isolated two-dimensional thunderstorm : sensitivity to cloud droplet size and the presence of graupel', Asia-Pacific Journal of Atmospheric Sciences, vol. 50, no. 2, pp. 139-151.en_US
dc.identifier.issn1976-7633 (print)
dc.identifier.issn1976-7951 (online)
dc.identifier.other10.1007/s13143-014-0003-z
dc.identifier.urihttp://hdl.handle.net/2263/39823
dc.language.isoenen_US
dc.publisherSpringeren_US
dc.rights© The Korean Meteorological Society and Springer 2014. The original publication is available at : http://link.springer.com/journal/13143en_US
dc.subjectAtmospheric modellingen_US
dc.subjectMicrophysics schemesen_US
dc.subjectThunderstormen_US
dc.subjectCold poolen_US
dc.subjectCloud Resolving Models (CRMs)en_US
dc.subjectBulk Microphysics Schemes (BMSs)en_US
dc.titleSimulations of an isolated two-dimensional thunderstorm : sensitivity to cloud droplet size and the presence of graupelen_US
dc.typePostprint Articleen_US

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Bopape_Simulations_2014.pdf
Size:
2.52 MB
Format:
Adobe Portable Document Format
Description:
Postprint Article

License bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description: