Bjorn Stevens
UCLA, Department of Atmospheric Sciences
Entrainment in Stratocumulus Clouds: Computational and Observational Challenges
Abstract: Stratocumulus clouds cover large expanses of the earth's surface and dramatically alter the radiative balance in their local region, and also globally. A key element to rationalizing climate change is understanding cloud feedbacks, i.e., how patterns of cloudiness might change in response to external forcings of the system. In this talk I review the basic physics of stratocumulus and illustrate how one particular process, namely entrainment at a stably stratified interface which tops the cloud layer, plays a central role in determining the cloud climatology and hence it susceptibility to external perturbations. Efforts to understand this entrainment process have thus become a focus of stratocumulus research. In the second part of my talk I present observational bounds on entrainment from the recent DYCOMS-II field study. The final part of my talk discusses how these bounds are being used to construct benchmarks for large-eddy simulation A particular effort will be made throughout to clearly express (for an audience of non-specialists) the basic physics of the problem, how it is framed for study using numerical simulation, as well as emerging questions and challenges.| Zeit: | Friday, August 15, 2003, 16.00 Uhr |
| Ort: | FU Berlin, Arnimallee 2-6, Raum 032 im EG |