Numerical experiments with a one-dimensional higher order turbulence model: Simulation of the Wangara Day 33 case
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A one-dimensional stratocumulus model is developed and incorporated into a cloud/mesoscale model to simulate the evolution of the marine stratocumulus-capped mixed layer.
This paper describes the formulation of the higher-order turbulence model. In a companion paper (Chen and Cotton, 1983), the formulation of the atmospheric radiation model, the partial condensation and the cloud fractional parameterization are described.
The second-order moments of this model are partially diagnosed. In order to close the system, the parameterization for the third-order moments given by Zeman and Lumley (1976) is adopted and is generalized to include total water and cloud water. A new scheme to parameterize the skewness terms is proposed in order to satisfy the enforced realizability. Those skewness terms are used to close the third-order moments.
In this paper, experiments are carried out to test the turbulence model by using the Wangara Day 33 data, which represents a ‘dry’ case study. Sensitivity experiments using the turbulence length scale parameterizations formulated by Andréet al. (1978) and Sun and Ogura (1980) are reformed and are compared.
KeywordsMixed Layer Scale Parameterization Turbulence Model Total Water Companion Paper
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