Journal ArticleDOI
a Study of the Broadening of Droplet Size Distributions in Cumuli
Abstract:
Cloud droplets may take a variety of paths to reach some location in a cloud and therefore may encounter varying growth conditions. This paper examines the effect of these variations on broadening of the droplet size distribution in cumuli. Diffusional growth of a collection of droplets is studied in detail using measurements obtained during the Cooperative Convective Precipitation Experiment (CCOPE) from the University of Wyoming's King Air research aircraft. A technique is described by which these measurements may be converted to the frame of reference of a moving droplet. Entrainment processes that are associated with variations in vertical velocity appear to have the effect of intensifying fluctuations in integral radius, which in turn produce variations in the supersaturation encountered by the droplets and thus opportunities for variations in growth. Contributions to spectral broadening arise from turbulent structures in the cloud, producing variations in integral radius as well as in the c...read more
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Journal ArticleDOI
Particle-turbulence interactions in atmospheric clouds
TL;DR: In this article, it is shown that fine-scale turbulence is of direct importance to the evolvability of clouds, and that microscale properties of clouds are determined to a great extent by thermodynamic and fluid-mechanical interactions between droplets and the surrounding air.
Journal ArticleDOI
Cloud Droplet Size Distributions in Low-Level Stratiform Clouds
TL;DR: A database of stratus cloud droplet (diameter <50 μm) size distribution parameters, derived from in situ data reported in the existing literature, was created, facilitating intercomparison among datasets and quantifying typical values and their variability.
Journal ArticleDOI
Notes on the state-of-the-art numerical modeling of cloud microphysics
TL;DR: The spectral (bin) microphysical approach, which does not restrict the particle size spectra to any particular shape and, therefore, claims to reproduce formation of size spectRA of cloud particles, is concerned.
Journal ArticleDOI
Preferential Concentration of Cloud Droplets by Turbulence: Effects on the Early Evolution of Cumulus Cloud Droplet Spectra
TL;DR: In this article, the authors present a mechanism for the broadening of cloud droplet spectra during condensational growth, based on the inherent turbulent nature of cumulus clouds, which operates independent of entrainment and can operate in adiabatic cloud cores.
Journal ArticleDOI
Effects of in-cloud nucleation and turbulence on droplet spectrum formation in cumulus clouds
Mark Pinsky,Alexander Khain +1 more
TL;DR: In this article, drop spectrum evolution is investigated using a moving mass grid microphysical cloud parcel model containing 2000 mass bins and allowing turbulent effects on droplet collisions, and it is shown that the presence of the secondary mode (the single-mode spectrum) can reduce or even inhibit formation of raindrops.