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

Malinowski, S.P., Haman, K.E., Kopec, M.K., Kumala, W., Gerber, H.

Journal of Physics: Conference Series

318(SECTION 7), 2011, 072013, doi:10.1088/1742-6596/318/7/072013

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.