Marine Stratocumulus Studies

点击翻译按钮获取中文摘要

The physical processes involved in the maintenance and dissipation of marine stratocumulus will be studied using aircraft observations and theoretical models. The observations for this study will be made using the NCAR Electra during the stratocumulus field phase of FIRE (First (International Satellite Cloud Climatology Project) Regional Experiment) to be conducted off the coast of southern California in July of 1987. The analysis will make use of mean, turbulence, cloud microphysics, and radiation measurements from the Electra. The overall objective is to improve and generalize methods for including stratocumulus processes in general circulation models. The specific focus is on entrainment and mixing processes at cloud top, convective circulations in marine stratocumulus, and processes that regulate the cloud fraction in broken cloud conditions. The theoretical effect will involve the development of a new low-order spectral model of convection that contains terms representing the effects of latent heating, entrainment, and radiative and surface heat fluxes, as well as the effects of a shearing background wind field. An analysis of the solutions to the model will produce the expected macrostructure of boundary layer circulations: for example, the horizontal wavelenghts and orientations of the embedded bands and the intensities of the circulations in the rows. These theoretical results will be compared with the structure obtained from the FIRE measurements.