A Three-Dimensional Scale-Adaptive Turbulent Kinetic Energy Scheme in the WRF-ARW Model

A new three-dimensional (3D) turbulent kinetic energy (TKE) subgrid mixing scheme is developed using the Advanced Research version of the Weather Research and Forecasting (WRF) Model (WRF-ARW) to address the gray-zone problem in the parameterization of subgrid turbulent mixing. The new scheme combin...

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Bibliographic Details
Published inMonthly weather review Vol. 146; no. 7; pp. 2023 - 2045
Main Authors Zhang, Xu, Bao, Jian-Wen, Chen, Baode, Grell, Evelyn D.
Format Journal Article
LanguageEnglish
Published Washington American Meteorological Society 01.07.2018
Subjects
Boundary layers
Computer simulation
Feasibility studies
Frameworks
General circulation models
Kinetic energy
Laboratories
Large eddy simulation
Large eddy simulations
Mixed layer
Oceanic eddies
Parameterization
Profiles
Simulation
Three dimensional models
Turbulent kinetic energy
Turbulent mixing
Vertical flux
Weather forecasting
United States > US
Colorado
China
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Summary:A new three-dimensional (3D) turbulent kinetic energy (TKE) subgrid mixing scheme is developed using the Advanced Research version of the Weather Research and Forecasting (WRF) Model (WRF-ARW) to address the gray-zone problem in the parameterization of subgrid turbulent mixing. The new scheme combines the horizontal and vertical subgrid turbulent mixing into a single energetically consistent framework, in contrast to the conventionally separate treatment of the vertical and horizontal mixing. The new scheme is self-adaptive to the grid-size change between the large-eddy simulation (LES) and mesoscale limits. A series of dry convective boundary layer (CBL) idealized simulations are carried out to compare the performance of the new scheme and the conventional treatment of subgrid mixing to the WRF-ARW LES dataset. The importance of including the nonlocal component in the vertical buoyancy specification in the newly developed general TKE-based scheme is illustrated in the comparison. The improvements of the new scheme with the conventional treatment of subgrid mixing across the gray-zone model resolutions are demonstrated through the partitioning of the total vertical flux profiles. Results from real-case simulations show the feasibility of using the new scheme in the WRF Model in lieu of the conventional treatment of subgrid mixing.
ISSN:0027-0644
1520-0493
DOI:10.1175/MWR-D-17-0356.1