Improving the representation of resolved and unresolved topographic effects on surface wind in the WRF model

AbstractThe Weather Research and Forecasting (WRF) model presents a high surface wind speed bias over plains and valleys that constitutes a limitation for the increasing use of the model for several applications. This study attempts to correct for this bias by parameterizing the effects that the unresolved topographic features exert over the momentum flux. The proposed parameterization is based on the concept of a momentum sink term and makes use of the standard deviation of the subgrid-scale orography as well as the Laplacian of the topographic field. Both the drag generated by the unresolved terrain and the possibility of an increase in the speed of the flow over the mountains and hills, where it is herein shown that WRF presents a low wind speed bias, are considered in the scheme. The surface wind simulation over a complex-terrain region that is located in the northeast of the Iberian Peninsula is improved with the inclusion of the new parameterization. In particular, the underestimation of the wind sp...

[1]  J. Dudhia,et al.  The Effect of Heat Waves and Drought on Surface Wind Circulations in the Northeast of the Iberian Peninsula during the Summer of 2003 , 2011 .

[2]  E. Xoplaki,et al.  North Atlantic atmospheric circulation and surface wind in the Northeast of the Iberian Peninsula: uncertainty and long term downscaled variability , 2011, Climate Dynamics.

[3]  J. Montávez,et al.  Quality Assurance of Surface Wind Observations from Automated Weather Stations , 2010 .

[4]  J. Dudhia,et al.  Surface Wind Regionalization over Complex Terrain: Evaluation and Analysis of a High-Resolution WRF Simulation , 2010 .

[5]  J. Gutiérrez,et al.  Diurnal surface wind variations over complex terrain , 2010 .

[6]  Jorge Navarro,et al.  A comparison of methodologies for monthly wind energy estimation , 2009 .

[7]  Christopher A. Davis,et al.  Temporal Changes in Wind as Objects for Evaluating Mesoscale Numerical Weather Prediction , 2009 .

[8]  J. Montávez,et al.  Climatology of wind patterns in the northeast of the Iberian Peninsula , 2009 .

[9]  L. D. Monache,et al.  VERIFICATION OF HIGH RESOLUTION WRF-RTFDDA SURFACE FORECASTS OVER MOUNTAINS AND PLAINS , 2009 .

[10]  J. Montávez,et al.  The influence of the Weibull assumption in monthly wind energy estimation , 2008 .

[11]  J. Montávez,et al.  Surface Wind Regionalization in Complex Terrain , 2008 .

[12]  G. Powers,et al.  A Description of the Advanced Research WRF Version 3 , 2008 .

[13]  V. Masson,et al.  The second compare exercise: A model intercomparison using a case of a typical mesoscale orographic flow, the pyrex iop3 , 2007 .

[14]  Daemon Fairless Renewable energy: Energy-Go-Round , 2007, Nature.

[15]  Tom Howard,et al.  Correction and downscaling of NWP wind speed forecasts , 2007 .

[16]  Hannes Isaak Reuter,et al.  An evaluation of void‐filling interpolation methods for SRTM data , 2007, Int. J. Geogr. Inf. Sci..

[17]  J. Dudhia,et al.  A New Vertical Diffusion Package with an Explicit Treatment of Entrainment Processes , 2006 .

[18]  Song‐You Hong,et al.  The WRF Single-Moment 6-Class Microphysics Scheme (WSM6) , 2006 .

[19]  L. Rontu A study on parametrization of orography‐related momentum fluxes in a synoptic‐scale NWP model , 2006 .

[20]  W. J. Steenburgh,et al.  Evaluation of Surface Sensible Weather Forecasts by the WRF and the Eta Models over the Western United States , 2005 .

[21]  Ligia R. Bernardet The Developmental Testbed Center Winter Forecasting Experiment (DWFE) , 2005 .

[22]  A. Beljaars,et al.  A new parametrization of turbulent orographic form drag , 2004 .

[23]  Representing Drag on Unresolved Terrain as a Distributed Momentum Sink , 2002 .

[24]  N. Wood,et al.  Turbulent Form Drag On Anisotropic Three-Dimensional Orography , 2001 .

[25]  Thomas A. Hennig,et al.  The Shuttle Radar Topography Mission , 2001, Digital Earth Moving.

[26]  N. Wood,et al.  Parametrizing the effects of orography on the boundary layer: An alternative to effective roughness lengths , 2001 .

[27]  E. Mlawer,et al.  Radiative transfer for inhomogeneous atmospheres: RRTM, a validated correlated-k model for the longwave , 1997 .

[28]  S. Milton,et al.  The Impact of Parameterized Subgrid-Scale Orographic Forcing on Systematic Errors in a Global NWP Model , 1996 .

[29]  N. Wood,et al.  The Pressure force induced by neutral, turbulent flow over hills , 1993 .

[30]  John S. Kain,et al.  Convective parameterization for mesoscale models : The Kain-Fritsch Scheme , 1993 .

[31]  J. Kain,et al.  A One-Dimensional Entraining/Detraining Plume Model and Its Application in Convective Parameterization , 1990 .

[32]  P. Mason,et al.  Observations of boundary-layer structure over complex terrain , 1990 .

[33]  J. Dudhia Numerical Study of Convection Observed during the Winter Monsoon Experiment Using a Mesoscale Two-Dimensional Model , 1989 .

[34]  Hans A. Panofsky,et al.  The geostrophic drag coefficient and the ‘effective’ roughness length , 1972 .