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Juerg Schmidli, Brian Billings, Fotini K. Chow, Stephan F. J. de Wekker, James Doyle, Vanda Grubišić, Teddy Holt, Qiangfang Jiang, Katherine A. Lundquist, Peter Sheridan, Simon Vosper, C. David Whiteman, Andrzej A. Wyszogrodzki, and Günther Zängl

and turbulence, and (iii) the uncertainties associated with the parameterization of radiation transfer and surface–atmosphere interactions. Thus apart from an idealized topography, the setup of the simulations is as close as possible to real-case simulations. The models are run with comprehensive model physics including a radiation transfer scheme, land surface scheme, and turbulence parameterization. A large computational domain and periodic lateral boundary conditions are used in order to

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Željko Večenaj, Stephan F. J. De Wekker, and Vanda Grubišić

applications, such as air pollution dispersion and wind energy. In these applications, turbulence parameters are used as an input to atmospheric dispersion models and wind energy efficiency. Turbulent kinetic energy (TKE) is one of those parameters that describe the turbulence intensity in the ABL. In high-resolution numerical modeling, turbulent mixing is often parameterized using TKE. To advance the development of turbulence parameterization schemes, it is therefore important to investigate and document

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James D. Doyle, Saša Gaberšek, Qingfang Jiang, Ligia Bernardet, John M. Brown, Andreas Dörnbrack, Elmar Filaus, Vanda Grubišić, Daniel J. Kirshbaum, Oswald Knoth, Steven Koch, Juerg Schmidli, Ivana Stiperski, Simon Vosper, and Shiyuan Zhong

elevation model [the National Oceanic and Atmospheric Administration (NOAA) National Geophysical Data Center Global Land One-kilometer Base Elevation (GLOBE)] is used to specify the terrain with a maximum height of ~3500 m. The terrain upstream of the Sierra Nevada and downstream of the second mountain range, the Inyos, is eliminated to isolate the local Sierra response. The terrain used in the ExSierra_fs and ExSierra_ns simulations is filtered to remove 2Δ x variations. Table 2. Parameters and

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Bowen Zhou and Fotini Katopodes Chow

surface layer. On the finest grid, the vertical resolution is 20 m with 5-m near-surface spacing. The land surface is represented with high-resolution terrain (10 m) and land cover (30 m) from the U.S. Geological Survey. A buffer zone of 10 grid points is used to merge topography between adjacent nests. A Rayleigh-damping layer is set for the top 33% of the domain for the 2400- and 240-m grid and top 20% for the 50-m grid. Some key model parameters are given in Table 1 . Table 1. List of nested

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Juerg Schmidli, Gregory S. Poulos, Megan H. Daniels, and Fotini K. Chow

using a sophisticated radiation package developed at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center [shortwave radiation is based on models of Chou (1990 , 1992 ) and longwave radiation is based on Chou and Suarez (1994) and Tao et al. (1996) ]. Topographic shading after Colette et al. (2003) was used. The land surface soil–vegetation model is based on the force–restore method (e.g., Noilhan and Planton 1989 ) and is described in detail in Xue et al

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Qingfang Jiang and James D. Doyle

Global Land One-km Base Elevation (GLOBE) dataset. The 1-km mesh is centered at Independence and the terrain in the 1-km mesh is shown Fig. 1b . For the four moist cases examined in this study, the model is initialized at 1200 UTC 20 March, 25 March, 31 March, and 11 April 2006, respectively, and integrated over 18 h. The first 4 h of each simulation is considered to be the spinup period and only the output data from the 4–18-h period are used for diagnosis. For each case, a pair of simulations have

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Peter Sheridan and Simon Vosper

than that in the valley (typically because of daytime solar warming within the valley) and, flowing over the Sierra Nevada, induces downslope winds by undercutting the valley atmosphere. Jiang and Doyle (2008) , in a study of diurnal variation of downslope winds in Owens Valley, demonstrated this effect for the case of only moderate mountaintop winds by using observations and high-resolution modeling, terming the flow “in-valley westerly.” Mayr and Armi (2010) show further evidence from T

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James D. Doyle and Dale R. Durran

) techniques. The 2D and 3D simulations are initialized using a reference state approximating the conditions upstream of the Colorado Front Range on 3 March 1991. This particular case is significant because, not only were rotors observed, but also because a United Airlines B737 crashed while attempting to land at Colorado Springs during the event. The sounding used to initialize the basic state in these simulations, as shown in Fig. 2 , is based on the potential temperature and cross-mountain wind

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Yanping Li, Ronald B. Smith, and Vanda Grubišić

-order-accurate Runge–Kutta scheme is used for the time integration. Fifth- and third-order-accurate spatial discretization schemes are used for the horizontal and vertical advection schemes, respectively. The National Centers for Environmental Prediction Global Forecast System PBL scheme is chosen to represent the effects of convective heat transfer in the vertical direction, together with a five-layer thermal diffusion scheme for the land surface scheme. Cumulus and microphysical parameterizations are not

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Qingfang Jiang, Ming Liu, and James D. Doyle

model grid area fraction of the dust-erodible soil, and is derived from a 1-km-resolution land cover dataset produced by the U.S. Geological Survey (USGS). The dry bed of Owens Lake is currently a salt flat whose surface is a mixture of clay, sand, and a variety of minerals. In this study, it is assumed that the dry bed is equally dust erodible and the A values have been reset to 1 in a source area similar to the one identified in Ono (2006) . The COAMPS model predicts ground wetness w s using a

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