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F. Couvreux, F. Guichard, P. H. Austin, and F. Chen

variability. 2. Methodology Fully coupled surface–atmospheric mesoscale models are powerful tools for the study of land–atmosphere interactions. Their representations of moist processes, cloud cover, and surface fluxes are however still incomplete (e.g., Betts 2004 ), and the nonlinear coupling between surface and atmosphere makes it difficult to isolate individual physical processes affecting boundary layer heterogeneity. The alternative and complementary approach employed in section 2b is to study

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

diurnal cycle than the west subdomain, and possesses a late night–early morning minimum and a broad midday-to-early-evening maximum in both simulations and observations. The ∼6-h later timing of the diurnal maximum of major events in the observations ( Fig. 14b ) in the east subdomain is the biggest discrepancy between the observations and the simulations. The reasons for this are unclear and not necessarily related to land surface–atmosphere interactions in the model. For example, differences in the

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

and Radiation Test bed (CART; Stokes and Schwartz 1994 ) and the four First International Satellite Land Surface Climatology Project (ISLSCP) Flux Experiment (FIFE; Sellers et al. 1992 ), and SGP-97 (more information is available online at http://hydrolab.arsusda.gov/sgp97/ ). In the mid-1990s, a group of scientists organized the Cooperative Atmosphere-Surface Exchange Study (CASES; LeMone et al. 2000 , Yates et al. 2001 ) to focus on land surface interaction in the Walnut River basin in

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Margaret A. LeMone, Mukul Tewari, Fei Chen, Joseph G. Alfieri, and Dev Niyogi

weather prediction models. Int. J. Remote Sens. , 19 , 1533 – 1543 . Holt , T. , D. Niyogi , F. Chen , K. Manning , M. LeMone , and A. Qureshi , 2006 : Effect of land–atmosphere interactions on the IHOP 24–25 May 2002 convection case. Mon. Wea. Rev. , 134 , 113 – 133 . Idso , S. B. , R. D. Jackson , R. J. Reginato , B. A. Kimball , and F. S. Nakayama , 1975 : The dependence of bare soil albedo on soil water content. J. Appl. Meteor. , 14 , 109 – 113 . Kang

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

-eddy simulations has shown that the interface between the ABL and the free atmosphere is influenced by processes related to land surface heterogeneity ( Avissar and Schmidt 1998 ; Patton et al. 2005 ). Concerning entrainment at the inversion layer and the boundary layer growth, there is still not a clear quantification of whether entrainment is enhanced by the heterogeneity of the underlying land surface ( Avissar and Schmidt 1998 ) or if it is similar to entrainment above homogeneous surfaces ( Patton et al

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

.7 km for TS1 versus 3.5 km for TS0.5). As in the case of 22 June, this trend was also evident without the filter (4.0, 2.4, and 1.8 km for TS1NF, TS0.5NFs, and TSmix1_0.33NFs, respectively). At the smallest atmosphere grid spacing with rolls (TSmix1_0.33NFs), their aspect ratio was 1.4, smaller than the expected land value (∼2–3 or slightly greater). There also appear to be secondary effects related to domain top and the presence or absence of nesting. As expected, deactivating the Knievel filter

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Robin L. Tanamachi, Wayne F. Feltz, and Ming Xue

thermal emission from the atmosphere.” The downwelling longwave infrared (3.3–19 μ m) radiances, combined with supplemental Rapid Update Cycle (RUC) numerical weather prediction model-generated profiles, were used to infer temperature and moisture profiles in the atmospheric column above the instrument. The reader is referred to Feltz et al. (2003b) and Knuteson et al. (2004a , b ) for a detailed description of the AERI instrument design and performance. During IHOP_2002, temperature and water

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Lindsay J. Bennett, Tammy M. Weckwerth, Alan M. Blyth, Bart Geerts, Qun Miao, and Yvette P. Richardson

structure of the boundary layer over land during synoptic-scale high pressure conditions has a well-defined diurnal evolution and has been described in terms of the vertical profile of virtual potential temperature θ υ ( Stull 1988 ) ( Fig. 1 ). During the early morning, the stable nocturnal boundary layer (NBL), characterized by an increase of θ υ with height, occupies the lowest few hundred meters and is overlaid by a neutrally stratified residual layer ( Fig. 1a ). Shortly after sunrise thermals

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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

in the MAPS land-surface scheme. J. Geophys. Res. , 105 , 4077 – 4086 . Smith , R. K. , 1988 : Travelling waves and bores in the lower atmosphere: The ‘Morning Glory’ and related phenomena. Earth-Sci. Rev. , 25 , 267 – 290 . Thomsen , G. L. , and R. K. Smith , 2006 : Simulations of low-level convergence lines over north-eastern Australia. Quart. J. Roy. Meteor. Soc. , 132 , 691 – 707 . Weckwerth , T. M. , and Coauthors , 2004 : An overview of the International H 2 O

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Robert J. Conzemius and Evgeni Fedorovich

patterns that are at least qualitatively comparable with the patterns that are observed in the atmosphere east of the dryline. 2. Observational input data and numerical setup The studied case was the 22 May 2002 convection initiation experiment that took place over the Oklahoma and Texas Panhandles. Numerous CBL measurements were taken on that day using a variety of mobile and fixed ground-based instruments as well as lidar- and radar-equipped aircraft. The target of the measurements was a north

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