Three-Dimensional Planetary Boundary Layer Parameterization for High-Resolution Mesoscale Simulations

Kosović, Branko; Munoz, Pedro Jimenez; Juliano, Timothy W.; Martilli, Alberto; Eghdami, Masih; Barros, Ana P.; Haupt, Sue Ellen

doi:10.1088/1742-6596/1452/1/012080

Cited by 21 publications

(14 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During night-time the simulation maintains the heat flux close to zero, mostly positive, whereas in observations the median heat flux is negative, with values around −0.02 K m s −1 . During daytime the magnitude of F H is noticeably underestimated, and extreme positive values are never reached, a similar behaviour than observed by [2]. Greater values of F H are given by LES during IOP daytime central hours in comparison to non-IOP days.…”

Section: Model Performance: Turbulent Quantitiessupporting

confidence: 78%

“…In this approach, the equations of the flow field are resolved using the Reynolds-averaged Navier-Stokes (RANS) technique where turbulent motions are fully parametrised [1]. Instead, if the horizontal cell grid size decreases to a few km or tens or hundreds of metres, the assumption of horizontal homogeneity is not valid and the effect of horizontal gradients of turbulent stresses and fluxes should be included [2]. Turbulence is explicitly resolved using the large eddy simulation (LES) approximation, where the large eddies are resolved and the small eddies are modelled in a sub-grid scheme.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

WRF-LES Simulation of the Boundary Layer Turbulent Processes during the BLLAST Campaign

Udina

Montornès²,

Casso³

et al. 2020

Atmosphere

View full text Add to dashboard Cite

A real case long-term nested large eddy simulation (LES) of 25-day duration is performed using the WRF-LES modelling system, with a maximum horizontal grid resolution of 111 m, in order to explore the ability of the model to reproduce the turbulence magnitudes within the first tens of metres of the boundary layer. Sonic anemometer measurements from a 60-m tower installed during the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign are used for verification, which is focused on the turbulent magnitudes in order to assess the success and limitations in resolving turbulent flow characteristics. The mesoscale and LES simulations reproduce the wind speed and direction fairly well, but only LES is able to reproduce the energy of eddies with lifetimes shorter than a few hours. The turbulent kinetic energy in LES simulation is generally underestimated during the daytime, mainly due to a vertical velocity standard deviation that is too low. The turbulent heat flux is misrepresented in the model, probably due to the inaccuracy of the sub-grid scheme.

show abstract

Section: Model Performance: Turbulent Quantitiessupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

WRF-LES Simulation of the Boundary Layer Turbulent Processes during the BLLAST Campaign

Udina

Montornès²,

Casso³

et al. 2020

Atmosphere

View full text Add to dashboard Cite

show abstract

“…The WRF model's applicability over steep terrain, a known issue when downscaling due to topographic features being better resolved, is likewise being extended, using both higher-order numerical methods (Arthur et al, 2021) as well as immersed boundary methods (Lundquist et al, 2012;Arthur et al, 2018). These methods have likewise not been adequately evaluated in relation to wind energy relevant flow information.…”

Section: Conclusion and Discussionmentioning

confidence: 99%

Evaluation of idealized large-eddy simulations performed with the Weather Research and Forecasting model using turbulence measurements from a 250 m meteorological mast

2021

View full text Add to dashboard Cite

Abstract. We investigate the ability of the Weather Research and Forecasting model to perform large-eddy simulation of canonical flows. This is achieved through comparison of the simulation outputs with measurements from sonic anemometers on a 250 m meteorological mast located at Østerild, in northern Denmark. Østerild is on a flat and rough area, and for the predominant wind directions, the atmospheric flow can be considered to be close to homogeneous. The idealized simulated flows aim at representing atmospheric boundary layer turbulence under unstable, neutral, and stable stability conditions at the surface, which are statistically significant conditions observed at Østerild. We found that the resolved fields from the simulations appear to have the characteristics of the three stability regimes. Vertical profiles of observed mean wind speeds and direction are well reproduced by the simulations, with the largest differences under near-neutral conditions, where the effect of the subgrid-scale model is evident on the vertical wind shear close to the surface. Vertical profiles of observed eddy fluxes are also well reproduced by the simulations, with the largest differences for the three velocity component variances under stable stability conditions, although nearly always within the observed variability. With regards to turbulent kinetic energy, we find good agreement between observations and simulations at all vertical levels. Simulated and observed velocity spectra match very well and show very similar behavior with height and with atmospheric stability within the low-frequency interval; at the effective resolution, the simulated spectra show the typical drop-off of finite differences. Our findings demonstrate that these idealized simulations reproduce the characteristics of atmospheric stability regimes often observed at a high turbulent and flat site within a direction sector, where the air flows over nearly homogeneous land.

show abstract

“…With the growing use of WRF at subkilometer scales across a broad user group, the need for a robust gray-zone modeling solution is urgent to ensure that research and technology decisions are based on reliable results. This modeling solution could also take the form of an adaptation of three-dimensional isotropic turbulence schemes [25,38,39].…”

Section: Discussionmentioning

confidence: 99%

Simulating Real Atmospheric Boundary Layers at Gray-Zone Resolutions: How Do Currently Available Turbulence Parameterizations Perform?

Doubrawa

Muñoz‐Esparza

2020

Atmosphere

View full text Add to dashboard Cite

Recent computational and modeling advances have led a diverse modeling community to experiment with atmospheric boundary layer (ABL) simulations at subkilometer horizontal scales. Accurately parameterizing turbulence at these scales is a complex problem. The modeling solutions proposed to date are still in the development phase and remain largely unvalidated. This work assesses the performance of methods currently available in the Weather Research and Forecasting (WRF) model to represent ABL turbulence at a gray-zone grid spacing of 333 m. We consider three one-dimensional boundary layer parameterizations (MYNN, YSU and Shin-Hong) and coarse large-eddy simulations (LES). The reference dataset consists of five real-case simulations performed with WRF-LES nested down to 25 m. Results reveal that users should refrain from coarse LES and favor the scale-aware, Shin-Hong parameterization over traditional one-dimensional schemes. Overall, the spread in model performance is large for the cellular convection regime corresponding to the majority of our cases, with coarse LES overestimating turbulent energy across scales and YSU underestimating it and failing to reproduce its horizontal structure. Despite yielding the best results, the Shin-Hong scheme overestimates the effect of grid dependence on turbulent transport, highlighting the outstanding need for improved solutions to seamlessly parameterize turbulence across scales.

show abstract

Three-Dimensional Planetary Boundary Layer Parameterization for High-Resolution Mesoscale Simulations

Cited by 21 publications

References 13 publications

WRF-LES Simulation of the Boundary Layer Turbulent Processes during the BLLAST Campaign

WRF-LES Simulation of the Boundary Layer Turbulent Processes during the BLLAST Campaign

Evaluation of idealized large-eddy simulations performed with the Weather Research and Forecasting model using turbulence measurements from a 250 m meteorological mast

Simulating Real Atmospheric Boundary Layers at Gray-Zone Resolutions: How Do Currently Available Turbulence Parameterizations Perform?

Contact Info

Product

Resources

About