2020/08/17 by Leif Denby, Denby, Leif, Steven Böing +7
Engineering · Environmental Science · #Atmospheric and Oceanic Physics (physics.ao-ph) #FOS: Physical sciences #Fluid Dynamics and Turbulent Flows #Particle Dynamics in Fluid Flows #Wind and Air Flow Studies
paper · pdf · doi:10.48550/arxiv.2008.07217
openalex publication_date 2020/08/17 · openalex created_date 2022/10/01 · openalex updated_date 2026/07/28
This paper presents two techniques for characterisation of cloud-feeding\ncoherent boundary layer structures through analysis of large-eddy simulations\nof shallow cumulus clouds, contrasting conditions with and without ambient\nshear. The first technique is a generalisation of the two-point correlation\nfunction where the correlation length-scale as well as orientation can be\nextracted. The second technique decomposes the vertical transport by coherent\nstructures by the shape, size and orientation of these structures. It is found\nthat the structures dominating the vertical flux are plume-like in character\n(extending from the surface into cloud), show small width/thickness asymmetry\nand rise near-vertically in the absence of ambient wind. The planar stretching\nand tilting of boundary layer structures caused by the introduction of ambient\nshear is also quantified, demonstrating the general applicability of the\ntechniques for future study of other boundary layer patterns.\n