MODELING THE MEAN AND TURBULENT STRUCTURE OF THE SUMMERTIME ARCTIC CLOUDY BOUNDARY-LAYER

This paper addresses the problem of modelling the summertime Arctic cl oudy boundary layer. Specifically we consider the problem of multi-lay ered clouds in the boundary layer that includes the decoupling of the turbulence between upper and lower clouds. A high-resolution one-dimen sional model with second-order turbulence closure and spectral radiati ve transfer is used to simulate a case study that was obtained during the 1980 Arctic Stratus Experiment. The effects of radiation, large-sc ale vertical motion and drizzle are investigated in sensitivity studie s. Results of this study show that radiative transfer is important to the maintenance of the multiple cloud layers, and suggest that weak ri sing vertical motion is the most favorable situation to maintain two s eparate cloud layers.