A DIAGNOSTIC MODEL OF TURBULENT TRANSPORT IN A CUMULUS CLOUD LAYER

Results are presented from a mixed-layer model which has been used to diagnose the average turbulent flux profiles in cumulus-capped boundar y-layers. The model makes use of separate mixed layer models for the c lear and cloudy parts of the broken cloud layer. It is shown, by compa rison with aircraft observations, that the model can be applied to est imate the area-averaged flux profiles under conditions in which the cl ouds penetrate the capping inversion. It is also shown that a small bu t significant part of the vertical transport results from the displace ment of air from above the inversion around the growing clouds.