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arXiv · 1911.10828

Laboratory Investigations of the Dynamics of Anomalous Entrainment in Cumulus-cloud flows

Sourabh S. Diwan·Roddam Narasimha·G. S. Bhat·K. R. Sreenivas
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Abstract

Anomalous entrainment in cumulus clouds has been a topic of investigation over many decades in the past. Its importance stems from the fact that entrainment rate is one of the major inputs to several cumulus-parameterization schemes. Recently Narasimha et al. (PNAS; 2011) have successfully simulated the large-scale dynamics of cumulus-cloud flows in the laboratory and provided a mechanistic explanation for the observed cumulus-entrainment anomalies. They showed a favourable comparison of a dilution-related quantity (called 'purity') between the laboratory measurements and cloud-resolving-model computations, and discussed the important problem of homogeneous vs. inhomogeneous mixing in cumulus clouds. The main purpose of the present report is to provide additional supporting information and a more detailed account of the entrainment-related issues not included in the PNAS paper due to space constraints. We believe this report, in conjunction with the paper, will present to the reader a comprehensive and more-or-less complete documentation on the issues mentioned above.

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Sourabh S. Diwan, Roddam Narasimha, G. S. Bhat, K. R. Sreenivas. 2019-11-25. Laboratory Investigations of the Dynamics of Anomalous Entrainment in Cumulus-cloud flows. https://arxiv.org/abs/1911.10828

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