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Steven E. Koch, Wayne Feltz, Frédéric Fabry, Mariusz Pagowski, Bart Geerts, Kristopher M. Bedka, David O. Miller, and James W. Wilson

; Rottman and Simpson 1989 ; Haase and Smith 1989a , b ). When there is a stable waveguide of sufficient depth at low levels to trap the vertical propagation of wave energy, a bore may evolve into a family of solitary waves known as a “soliton” ( Christie et al. 1979 ; Fulton et al. 1990 ; Skyllingstad 1991 ). A solitary wave consists of a single wave of elevation that, owing to a balance between nonlinearity and dispersion, propagates without change of form. IHOP provided an unprecedented set of

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Robert J. Conzemius and Evgeni Fedorovich

of CBL statistics taken 3 times during the simulation. The first is at 1252 UTC, when the boundary layer is undergoing transition from a nocturnal planetary boundary layer (PBL) to a sheared CBL. The second is at 1944 UTC, when the entrainment flux ratio decreases to about 0.2 and the CBL evolution is governed primarily by shear-free dynamics. Additionally, Homestead Integrated Sounding System (ISS) radiosonde data are available at this time for comparison. The final time is 0000 UTC (23 May

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Margaret A. LeMone, Fei Chen, Mukul Tewari, Jimy Dudhia, Bart Geerts, Qun Miao, Richard L. Coulter, and Robert L. Grossman

conditions. Moreover, CBL structure can be influenced by interaction with tropospheric gravity waves (e.g., Clark et al. 1986 ; Balaji et al. 1993 ), requiring inclusion of a deeper domain than ordinarily used in LES. These factors, along with the convenience of having an NWP model with a reasonably robust surface model, led to the choice to run ARW-WRF run at 1-km resolution. We recognize the potential problems created by “double counting” associated with partially resolving CBL-scale motions and

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Monica Górska, Jordi Vilà-Guerau de Arellano, Margaret A. LeMone, and Chiel C. van Heerwaarden

method is the ability to study the correlations between the surface characteristics and the turbulent fluxes at different heights. The variability of the surface properties is quantified in terms of the normalized differential vegetation index (NDVI), which represents the proportion of photosynthetic activity. NDVI is measured by the aircraft using reflectance from the red ( ρ red ) and near-infrared ( ρ nIR ) wave bands and is defined as The aircraft measurements were supplemented with surface

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Edward I. Tollerud, Fernando Caracena, Steven E. Koch, Brian D. Jamison, R. Michael Hardesty, Brandi J. McCarty, Christoph Kiemle, Randall S. Collander, Diana L. Bartels, Steven Albers, Brent Shaw, Daniel L. Birkenheuer, and W. Alan Brewer

, particularly in the eastern half of the leg, that were noted previously. Because dropsonde spacing cannot resolve variations of tens of kilometers in the horizontal dimension and can only marginally capture the longer waves, there are no data available to further explain the physical nature of these variations. Of particular interest to our study is the possibility that these small-scale horizontal features and vertical layers of moisture and wind could correlate strongly enough that operational

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S. B. Trier, F. Chen, K. W. Manning, M. A. LeMone, and C. A. Davis

on seasonal precipitation amounts (e.g., Koster et al. 2004a , b ; Ruiz-Barradas and Nigam 2005 ). In this paper, we use a three-dimensional atmospheric model coupled with different land surface models (LSMs) to examine relationships between the land surface, the planetary boundary layer (PBL), and precipitation. The PBL evolution is a potentially important linkage between soil moisture and precipitation because soil wetness has been observed to strongly impact the daytime moist static energy

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