Simulation of Atmospheric Boundary Layer Processes Using Local- and Nonlocal-Closure Schemes

A soil‐vegetation‐atmospheric boundary layer model was developed to study the performance of two localclosure and two nonlocal-closure boundary layer mixing schemes for use in meteorological and air quality simulation models. Full interaction between the surface and atmosphere is achieved by representing surface characteristics and associated processes using a prognostic soil‐vegetation scheme and atmospheric boundary layer schemes. There are 30 layers in the lowest 3 km of the model with a high resolution near the surface. The four boundary layer schemes are tested by simulating atmospheric boundary layer structures over densely and sparsely vegetated regions using the observational data from the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment (FIFE) and from Wangara. Simulation results indicate that the near-surface turbulent fluxes predicted by the four boundary layer schemes differ from each other, even though the formulation used to represent the surface-layer processes is the same. These differences arise from the differing ways of representing subgrid-scale vertical mixing processes. Results also indicate that the vertical profiles of predicted parameters (i.e., temperature, mixing ratio, and horizontal winds) from the four mixed-layer schemes differ from each other, particularly during the daytime growth of the mixed layer. During the evening hours, after the mixed layer has reached its maximum depth, the differences among these respective predicted variables are found to be insignificant. There were some general features that were associated with each of the schemes in all of the simulations. Compared with observations, in all of the cases the simulated maximum depths of the boundary layer for each scheme were consistently either lower or higher, superadiabatic lapse rates were consistently either stronger or weaker, and the intensity of the vertical mixing was either stronger or weaker. Also, throughout the simulation period in all case studies, most of the differences in the predicted parameters are present in the surface layer and near the top of the mixed layer.

[1]  Y. Kuo,et al.  Description of the Penn State/NCAR Mesoscale Model: Version 4 (MM4) , 1987 .

[2]  Ulrich Schumann,et al.  Large-eddy simulation of turbulent diffusion with chemical reactions in the convective boundary layer , 1989 .

[3]  D. Etling,et al.  Application of the E-ε turbulence model to the atmospheric boundary layer , 1985 .

[4]  Paulette Middleton,et al.  A three‐dimensional Eulerian acid deposition model: Physical concepts and formulation , 1987 .

[5]  G. Mellor,et al.  A Hierarchy of Turbulence Closure Models for Planetary Boundary Layers. , 1974 .

[6]  F. S. Nakayama,et al.  The Dependence of Bare Soil Albedo on Soil Water Content. , 1975 .

[7]  W. Gao,et al.  Numerical Modeling of the Turbulent Fluxes of Chemically Reactive Trace Gases in the Atmospheric Boundary Layer , 1994 .

[8]  J. Mahfouf,et al.  A Comparative Study of Various Parameterizations of the Planetary Boundary Layer in a Numerical Mesoscale Model , 1987 .

[9]  K. Alapaty,et al.  Simulation of monsoon boundary-layer processes using a regional scale nested grid model , 1994 .

[10]  G. Grell,et al.  A description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5) , 1994 .

[11]  S. Planton,et al.  A Simple Parameterization of Land Surface Processes for Meteorological Models , 1989 .

[12]  J. Deardorff.  Efficient prediction of ground surface temperature and moisture, with inclusion of a layer of vegetation , 1978 .

[13]  R. Stull,et al.  Applications of the transilient turbulence parameterization to atmospheric boundary-layer simulations , 1987 .

[14]  J. Noilhan,et al.  Sensitivity study and validation of a land surface parameterization using the HAPEX-MOBILHY data set , 1990 .

[15]  A. Holtslag,et al.  A High Resolution Air Mass Transformation Model for Short-Range Weather Forecasting , 1990 .

[16]  Numerical Study of a Cold Air Outbreak over the Ocean , 1988 .

[17]  Simulation of a Wet Deposition Case in Europe Using the European Acid Deposition Model (EURAD) , 1991 .

[18]  Julius Chang,et al.  A non-local closure model for vertical mixing in the convective boundary layer , 1992 .

[19]  B. Hicks.  An analysis of Wangara micrometeorology : surface stress, sensible heat, evaporation, and dewfall , 1981 .

[20]  P. Sellers,et al.  The First ISLSCP Field Experiment (FIFE) , 1988 .

[21]  E. F. Bradley,et al.  Flux-Profile Relationships in the Atmospheric Surface Layer , 1971 .