Intercomparison and interpretation of single-column model simulations of a nocturnal stratocumulus-topped marine boundary layer

Ten single-column models (SCMs) from eight groups are used to simulate a nocturnal nonprecipitating
marine stratocumulus-topped mixed layer as part of an intercomparison organized by the Global Energy
and Water Cycle Experiment Cloud System Study, Working Group 1. The case is idealized from observations
from the Dynamics and Chemistry of Marine Stratocumulus II, Research Flight 1. SCM simulations
with operational resolution are supplemented by high-resolution simulations and compared with observations
and large-eddy simulations. All participating SCMs are able to maintain a sharp inversion and a mixed
cloud-topped layer, although the moisture profiles show a slight gradient in the mixed layer and produce
entrainment rates broadly consistent with observations, but the liquid water paths vary by a factor of 10
after only 1 h of simulation at both high and operational resolution. Sensitivity tests show insensitivity to
activation of precipitation and shallow convection schemes in most models, as one would observationally
expect for this case.