9217028 Sorbjan The PIs propose to use large eddy simulation model with a nested grid to develop new and improve existing parameterizations of dynamic and thermal effects in the atmospheric mixed layer. Initially, idealized simulations of the following four regimes of the convective boundary layer will be performed: (1) non- penetrative and shearless, (2) penetrative and shearless, (3) non- penetrative with shear, and (4) penetrative with shear. From these, a comparison of non-penetrative and penetrative shearless regimes will be used to investigate entrainment processes on the top of the CBL. In addition, a study of the shearless and sheared regimes will be performed to develop a parameterization the sheared CBL. Furthermore, they will also investigate effects of moist convection with cumulus-humilis type of clouds on dynamics of the mixed layer. Finally, they will attempt to test parameterizations of the sheared CBL regimes through comparison with observations taken during the Phoenix and the Stormfest experiments. The developed parameterizations are hoped to be used in numerical weather prediction and climate simulation models. ***
