Implementation and evaluation of dynamic subfilter-scale stress models for large-eddy simulation using WRF

Gokhan Kirkil, Jeff Mirocha, Elie R. Bou-Zeid, Fotini Katopodes Chow, Branko Kosović

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

The performance of a range of simple to moderately complex subfilter-scale (SFS) stress models implemented in the Weather Research and Forecasting (WRF) model is evaluated in large-eddy simulations of neutral atmospheric boundary layer flow over both a flat terrain and a two-dimensional symmetrical transverse ridge. Two recently developed dynamic SFS stress models, the Lagrangian-averaged scale-dependent (LASD) dynamic model and the dynamic reconstruction model (DRM), are compared with theWRFmodel's existing constant-coefficient linear eddy-viscosity and (as of version 3.2) nonlinear SFS stressmodels to evaluate the benefits of more sophisticated and accurate, but also more computationally expensive approaches. Simulation results using the different SFS stress models are compared among each other, as well as against the Monin-Obukhov similarity theory. For the flat terrain case, vertical profiles of mean wind speed from the newly implemented dynamic models show the best agreement with the similarity solution, improving even upon the nonlinear model, which likewise yields a significant improvement compared to the Smagorinsky model. The more sophisticated SFS stress models more successfully predict the expected production and inertial range scaling of power spectra, especially near the surface, with the dynamic models achieving the best scaling overall. For the transverse ridge case, the nonlinear model predicts the greatest amount of reverse flow in the lee of the ridge, and also demonstrates the greatest ability to duplicate qualitative features of the highest-resolution simulations at coarser resolutions. The dynamic models' flow distributions in the lee of the ridge did not differ significantly from the constant-coefficient Smagorinsky model.

Original languageEnglish (US)
Pages (from-to)266-284
Number of pages19
JournalMonthly Weather Review
Volume140
Issue number1
DOIs
StatePublished - Jan 1 2012

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

Keywords

  • Atmosphere-land interaction
  • Atmosphere-land interactions
  • Boundary layer
  • Complex terrain
  • Eddies
  • Large eddy simulations
  • Small scale processes
  • Subgrid-scale processes
  • Surface layer
  • Wind
  • Wind shear

Fingerprint Dive into the research topics of 'Implementation and evaluation of dynamic subfilter-scale stress models for large-eddy simulation using WRF'. Together they form a unique fingerprint.

  • Cite this