Physical Sciences and Mathematics Commons^™

Mixing In Shallow Cumulus Clouds Studied By Lagrangian Particle Tracking, Thijs Heus, Gertjan Van Dijk, Harmen J.J. Jonker, Harry E.A. Van Den Akker

Physics Faculty Publications

Mixing between shallow cumulus clouds and their environment is studied using large-eddy simulations. The origin of in-cloud air is studied by two distinct methods: 1) by analyzing conserved variable mixing diagrams (Paluch diagrams) and 2) by tracing back cloud-air parcels represented by massless Lagrangian particles that follow the flow. The obtained Paluch diagrams are found to be similar to many results in the literature, but the source of entrained air found by particle tracking deviates from the source inferred from the Paluch analysis. Whereas the classical Paluch analysis seems to provide some evidence for cloud-top mixing, particle tracking shows that …