Print Email Facebook Twitter On the Deceiving Aspects of Mixing Diagrams of Deep Cumulus Convection Title On the Deceiving Aspects of Mixing Diagrams of Deep Cumulus Convection Author Boing, S.J. Jonker, H.J.J. Nawara, W.A. Siebesma, A.P. Faculty Civil Engineering and Geosciences Department Geoscience & Remote Sensing Date 2014-01-01 Abstract Mixing processes in deep precipitating cumulus clouds are investigated by tracking Lagrangian particles in a large-eddy simulation. The trajectories of particles are reconstructed and the thermodynamic properties of cloud air are studied using mixing diagrams. The trajectory analysis shows that the in-cloud mixing is entirely dominated by lateral entrainment and that there is no significant vertical mixing by downdrafts originating from cloud top. Yet the thermodynamic properties of the particles are located close to a line in the mixing diagrams, which appears to be consistent with two-point vertical mixing. An attempt is made to resolve this paradox using the buoyancy-sorting model of Taylor and Baker, but it is found that this model does not provide a full explanation for the location of particles in the mixing diagram. However, it is shown that the mixing-line behavior can be well understood from a simple analytically solvable model that uses a range of different lateral entrainment rates. Two further factors that determine the location of particles in the mixing diagram are identified: the removal of noncloudy air and precipitation effects. Finally, a thermodynamic argument is given that explains the absence of coherent downdrafts descending from cloud top. To reference this document use: http://resolver.tudelft.nl/uuid:8e5ef661-c115-463e-ac17-bcbc8dfe39a6 DOI https://doi.org/10.1175/JAS-D-13-0127.1 Publisher American Meteorological Society Embargo date 2014-06-01 ISSN 0022-4928 Source Journal of the Atmospheric Science, 71 (1), 2014 Part of collection Institutional Repository Document type journal article Rights (c) 2014 American Meteorological Society Files PDF 297620.pdf 2.58 MB Close viewer /islandora/object/uuid:8e5ef661-c115-463e-ac17-bcbc8dfe39a6/datastream/OBJ/view