UPSHEAR AND DOWNSHEAR EVOLUTION OF CLOUD STRUCTURE AND SPECTRAL PROPERTIES

Citation
Pa. Vaillancourt et al., UPSHEAR AND DOWNSHEAR EVOLUTION OF CLOUD STRUCTURE AND SPECTRAL PROPERTIES, Journal of the atmospheric sciences, 54(9), 1997, pp. 1203-1217
Citations number
37
Categorie Soggetti
Metereology & Atmospheric Sciences
ISSN journal
00224928
Volume
54
Issue
9
Year of publication
1997
Pages
1203 - 1217
Database
ISI
SICI code
0022-4928(1997)54:9<1203:UADEOC>2.0.ZU;2-L
Abstract
A dynamical model, in conjunction with a microphysical model designed to predict evolution of cloud droplet spectra, is employed to perform two-dimensional simulations of a small nonprecipitating cumulus cloud in the presence of wind shear. Upshear-downshear differences in terms of entrainment sites, mixing zones, degree of dilution, and spectral p roperties are investigated and compared to some observations. Results show no systematic differences between the upshear and downshear sides of individual cloud turrets composed of cloudy air of rather uniform age. However, important differences in the spectral properties are not ed between new cloudy air growing on the upshear side of the cloud and older cloudy volumes dissipating on the downshear side of the cloud. It is found that stronger wind shear inhibits the interaction between cloud turrets of different ages.