Small-scale turbulent mixing at stratocumulus top observed by means of high resolution airborne temperature and LWC measurements

Abstract

High resolution measurements of temperature and cloud water, collected during Physics of Stratocumulus Top experiment are investigated. Two case studies presented here illustrate differences between "classical" stratocumulus capped with a sharp inversion and dry layer above and one type of "nonclassical" stratocumulus with weak inversion with moist air above. Entrainment and tranport into the cloud deck are investigated by means of statistical analysis of LWC and temperature fluctuations. It comes, that in "classical" case downdrafts with depleted water content are characterized with reduced temperature (effect of evaporative cooling, presumably negative buoyancy), while in this "non classical" case such downdrafts are of increased temperature, suggesting that in this case evaporative cooling is not a driving mechannism of downward transport.