This is a past event.

This talk is not about building fences, but about aircraft measurements during the POST (Physics of Stratocumulus Top) field study of stratocumulus clouds (Sc) off the West Coast of California. And “holes” are narrow features in Sc related to the entrainment of dryer air from aloft into Sc, a process that can shorten the lifetime of Sc. It is well accepted that the broad global coverage Sc off the western margin of continents produces the largest solar reflectance (albedo) of any cloud type. It thus is essential to predict their future coverage accurately given their strong influence on the global radiation balance and their effect on climate change. The current understanding of basic physical processes in Sc is still unsatisfactory making Sc behavior in climate models uncertain. It has been a long and ongoing effort by many to try and understand entrainment sufficiently. 

POST was designed to take a unique look at entrainment and cloud holes in Sc by using very fast sensors including the UFT (Ultra-Fast Temperature) probe and the PVM (Particle Volume Monitor) for droplet properties. The POST field effort is briefly described, results include measurements and how those compare to previous research, and conclusions are given as to how entrainment should now be looked at in comparison to existing consensus.

Seminar by:

Hermann Gerber, PhD

President and Chief Scientist of Gerber Scientific Inc. 

Adjunct Professor, Dept. of Atmospheric Sciences, University of Utah