Fine-scale structure and mixing within an inversion

This paper describes some of the results that were obtained in an experimental study of an inversion capping a convective boundary layer, during which a balloon-borne probe was flown through the actual interface at the same time as it was scanned by a high power 10-cm Doppler radar. The initial analysis has revealed several interesting features including the possible presence of small-scale Kelvin-Helmholtz billows at the crest of the hummocks of the inversion and the absence of an inertial subrange. A model is proposed for the transfer of sensible heatdownwards across the inversion. This is hypothesised as a two-stage process — sporadic thickening by the entrainment of air from above and below due to the action of the breaking billows, and a continual erosion of the lower surface by convective activity.