Abstract: Stratocumuli are very important to the global radiative budget, due to their long residence time and the large area commonly covered by such clouds. Most of the general circulation models (GCMs), however, are incapable of properly simulate the evolution of the stratocumulus-topped boundary-layer, probably due to deficiencies in their physical parameterizations. In this work, several e-l (turbulent kinetic energy M-^V mixing length) closure turbulence parameterization schemes are compared. The comparison is made through single-column model simulations of real cases, observed during the 2nd Aerosol Characterization Experiment (ACE2). A new scheme, in which the mixing length is obtained from the maximum value in the vertical velocity variance spectrum, produces results that are superior than the ones attained with other published parameterizations, in both coupled and decoupled cases.