Analysis of CASES99 data using eddy correlation data at 7 different levels suggest a variety of vertical structures of the stable boundary layer including cases where the turbulence is generated primarily by shear above 50 m, which intermittently bursts downward to the earth's surface. In some cases, the surface-based boundary layer appears to be only a few meters deep. In other cases, a boundary layer seems undefinable from the data.

Traditional models fail to even qualitatively predict the correct vertical structure for some of the cases. An improved mixing length formulation is developed to better describe the dramatic variation in observed vertical structure, although significant discrepancies remain.