scholarly journals A New Boundary Layer Mixing Scheme. Part II: Tests in Climate and Mesoscale Models

2000 ◽  
Vol 128 (9) ◽  
pp. 3200-3217 ◽  
Author(s):  
G. M. Martin ◽  
M. R. Bush ◽  
A. R. Brown ◽  
A. P. Lock ◽  
R. N. B. Smith
2021 ◽  
Author(s):  
Alfredo Peña ◽  
Jeffrey Mirocha

<p>Mesoscale models, such as the Weather Research and Forecasting (WRF) model, are now commonly used to predict wind resources, and in recent years their outputs are being used as inputs to wake models for the prediction of the production of wind farms. Also, wind farm parametrizations have been implemented in the mesoscale models but their accuracy to reproduce wind speeds and turbulent kinetic energy fields within and around wind farms is yet unknown. This is partly because they have been evaluated against wind farm power measurements directly and, generally, a lack of high-quality observations of the wind field around large wind farms. Here, we evaluate the in-built wind farm parametrization of the WRF model, the so-called Fitch scheme that works together with the MYNN2 planetary boundary layer (PBL) scheme against large-eddy simulations (LES) of wakes using a generalized actuator disk model, which was also implemented within the same WRF version. After setting both types of simulations as similar as possible so that the inflow conditions are nearly identical, preliminary results show that the velocity deficits can differ up to 50% within the same area (determined by the resolution of the mesoscale run) where the turbine is placed. In contrast, within that same area, the turbine-generated TKE is nearly identical in both simulations. We also prepare an analysis of the sensitivity of the results to the inflow wind conditions, horizontal grid resolution of both the LES and the PBL run, number of turbines within the mesoscale grid cells, surface roughness, inversion strength, and boundary-layer height.</p>


2004 ◽  
Vol 38 (17) ◽  
pp. 2665-2675 ◽  
Author(s):  
Carmen J. Nappo ◽  
Hye-Yeong Chun ◽  
Hyuk-Je Lee

2016 ◽  
Vol 73 (7) ◽  
pp. 2603-2614 ◽  
Author(s):  
Domingo Muñoz-Esparza ◽  
Jeremy A. Sauer ◽  
Rodman R. Linn ◽  
Branko Kosović

Abstract Mesoscale models are considered to be the state of the art in modeling mountain-wave flows. Herein, the authors investigate the role and accuracy of planetary boundary layer (PBL) parameterizations in handling the interaction between large-scale mountain waves and the atmospheric boundary layer. To that end, recent large-eddy simulation (LES) results of mountain waves over a symmetric two-dimensional bell-shaped hill are used and compared to four commonly used PBL schemes. It is found that one-dimensional PBL parameterizations produce reasonable agreement with the LES results in terms of vertical wavelength, amplitude of velocity, and turbulent kinetic energy distribution in the downhill shooting-flow region. However, the assumption of horizontal homogeneity in PBL parameterizations does not hold in the context of these complex flow configurations. This inappropriate modeling assumption results in a vertical wavelength shift, producing errors of approximately 10 m s−1 at downstream locations because of the presence of a coherent trapped lee wave that does not mix with the atmospheric boundary layer. In contrast, horizontally integrated momentum flux derived from these PBL schemes displays a realistic pattern. Therefore, results from mesoscale models using ensembles of one-dimensional PBL schemes can still potentially be used to parameterize drag effects in general circulation models. Nonetheless, three-dimensional PBL schemes must be developed in order for mesoscale models to accurately represent complex terrain and other types of flows where one-dimensional PBL assumptions are violated.


Author(s):  
Sven-Erik Gryning ◽  
E. Batchvarova ◽  
Alexander Baklanov ◽  
Georg Grell ◽  
W. C. de Rooy ◽  
...  

2011 ◽  
Vol 116 (D23) ◽  
pp. n/a-n/a ◽  
Author(s):  
G. J. Steeneveld ◽  
L. F. Tolk ◽  
A. F. Moene ◽  
O. K. Hartogensis ◽  
W. Peters ◽  
...  

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