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P. J. Sellers, B. W. Meeson, J. Closs, J. Collatz, F. Corprew, D. Dazlich, F. G. Hall, Y. Kerr, R. Koster, S. Los, K. Mitchell, J. McManus, D. Myers, K.-J. Sun, and P. Try

A comprehensive series of global datasets for land-atmosphere models has been collected, formatted to a common grid, and released on a set of CD-ROMs. This paper describes the motivation for and the contents of the dataset.

In June of 1992, an interdisciplinary earth science workshop was convened in Columbia, Maryland, to assess progress in land-atmosphere research, specifically in the areas of models, satellite data algorithms, and field experiments. At the workshop, representatives of the land-atmosphere modeling community defined a need for global datasets to prescribe boundary conditions, initialize state variables, and provide near-surface meteorological and radiative forcings for their models. The International Satellite Land Surface Climatology Project (ISLSCP), a part of the Global Energy and Water Cycle Experiment, worked with the Distributed Active Archive Center of the National Aeronautics and Space Administration Goddard Space Flight Center to bring the required datasets together in a usable format. The data have since been released on a collection of CD-ROMs.

The datasets on the CD-ROMs are grouped under the following headings: vegetation; hydrology and soils; snow, ice, and oceans; radiation and clouds; and near-surface meteorology. All datasets cover the period 1987–88, and all but a few are spatially continuous over the earth's land surface. All have been mapped to a common 1° × 1° equal-angle grid. The temporal frequency for most of the datasets is monthly. A few of the near-surface meteorological parameters are available both as six-hourly values and as monthly means.

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Thomas T. Warner, Ralph A. Peterson, and Russell E. Treadon

Limited-area models (LAMs) are presently used for a wide variety of research and operational forecasting applications, and such use will likely expand greatly as the rapid increase in the performance/price ratio of computers and workstations makes LAMs more accessible to novice users. The robustness of these well-tested and documented models will make it tempting for many to consider them as turn-key systems that can be used without any experience or formal training in numerical weather prediction. This paper is intended as a tutorial and caution for such prospective model users, with the specific purpose of illustrating that, in spite of advanced physical-process parameterizations and high resolutions permitted by faster computers, and modern mesoscale data for initial conditions, there is still a basic limitation to predictability with a LAM—lateral boundary conditions (LBC). Illustrations are provided of previous work that show the serious negative effects of LBCs, and guidelines are provided for helping to minimize their negative impact on forecast quality.

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Stephan T. Kral, Joachim Reuder, Timo Vihma, Irene Suomi, Kristine F. Haualand, Gabin H. Urbancic, Brian R. Greene, Gert-Jan Steeneveld, Torge Lorenz, Björn Maronga, Marius O. Jonassen, Hada Ajosenpää, Line Båserud, Phillip B. Chilson, Albert A. M. Holtslag, Alastair D. Jenkins, Rostislav Kouznetsov, Stephanie Mayer, Elizabeth A. Pillar-Little, Alexander Rautenberg, Johannes Schwenkel, Andrew W. Seidl, and Burkhard Wrenger

boundary layer (ABL) parameterizations and have a strong need for an improved representation of the SBL, in particular in very stable boundary layer (VSBL) conditions. This is demonstrated by large errors under VSBL conditions, where 2-m air temperature errors (∆ T 2m ) on the order of 10 K are common even in short-term (24-h) NWP products ( Atlaskin and Vihma 2012 ). In atmospheric reanalyses, broadly applied in diagnostics of climate variability and change, the monthly/seasonal means of ∆ T 2m in

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A. A. M. Holtslag, G. Svensson, P. Baas, S. Basu, B. Beare, A. C. M. Beljaars, F. C. Bosveld, J. Cuxart, J. Lindvall, G. J. Steeneveld, M. Tjernström, and B. J. H. Van De Wiel

The atmospheric boundary layer impacts strongly the model performance for temperature and wind, yet stable situations, such as in clear, calm conditions at night or over ice, remain problematic. The atmospheric boundary layer (ABL) is the lower part of the atmosphere that is in continuous interaction with Earth's surface owing to friction and heating or cooling. The ABL is generally turbulent and has a pronounced diurnal cycle of temperature, wind, and related variables—in particular over land

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Daniel T. Lindsey, Dan Bikos, and Lewis Grasso

vapor mixing ratio in g kg −1 , and the vertical axes are pressure in hPa. Yellow lines marked B are the approximate locations of the surface boundary as described in the text. The center of the domain in the plan view is western Kansas. Convective evolution is dependent not only on surface conditions but also on above-the-surface profiles of temperature and water vapor, particularly in the boundary layer. Figures 2c and 2d show north–south vertical cross sections across the cyan line in Figs. 2a

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Andrew M. Vogelmann, Greg M. McFarquhar, John A. Ogren, David D. Turner, Jennifer M. Comstock, Graham Feingold, Charles N. Long, Haflidi H. Jonsson, Anthony Bucholtz, Don R. Collins, Glenn S. Diskin, Hermann Gerber, R. Paul Lawson, Roy K. Woods, Elisabeth Andrews, Hee-Jung Yang, J. Christine Chiu, Daniel Hartsock, John M. Hubbe, Chaomei Lo, Alexander Marshak, Justin W. Monroe, Sally A. McFarlane, Beat Schmid, Jason M. Tomlinson, and Tami Toto

, and the number of flight hours dedicated to each objective is summarized in Fig. 2 . Fig. 2. RACORO flight hour distributions per objective. Total flight hours are plotted per primary objective: cloud sampling, boundary layer turbulence characterization, aerosol characterization, surface albedo mapping, and radiometer tilt-correction characterization. The ferry time to and from the study site is provided, which also was used to scout the conditions in preparation for the on-site patterns (e

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Otávio C. Acevedo, Gervásio A. Degrazia, Franciano S. Puhales, Luis G. N. Martins, Pablo E. S. Oliveira, Claudio Teichrieb, Samuel M. Silva, Rafael Maroneze, Bardo Bodmann, Luca Mortarini, Daniela Cava, and Domenico Anfossi

observations made in idealized conditions ( Kaimal et al. 1976 ; Caughey and Palmer 1979 ; Caughey et al. 1979 ). However, the conditions of horizontal homogeneity, stationarity, and fully developed turbulence, on which similarity theory is based, are often violated in the real-world atmospheric boundary layer. In recent years the study of heterogeneous surfaces and nonstationary and intermittent turbulence have, in fact, become some of the major areas of micrometeorological research. It is not certain

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Jelle Treep, Gil Bohrer, Judy Shamoun-Baranes, Olivier Duriez, Renato Prata de Moraes Frasson, and Willem Bouten

boundary layer properties, such as thermal structures, are scarce, especially in remote and mountainous locations. In this paper we demonstrate an approach for using GPS data of soaring birds to observe atmospheric boundary layer properties. BIRD FLIGHT IS STRONGLY RELATED TO METEOROLOGICAL CONDITIONS. Many large birds use soaring and gliding flight because flapping flight is energetically more costly ( Hedenstrom 1993 ; Sakamoto et al. 2013 ; Duriez et al. 2014 ). Birds that use thermal convection

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N. Voisin, M. Kintner-Meyer, D. Wu, R. Skaggs, T. Fu, T. Zhou, T. Nguyen, and I. Kraucunas

operations, and particularly during hot and dry conditions when grid stress is typically most acute. Voisin et al. (2016) directly linked integrated hydrology simulations with a unit commitment and economic dispatch (UCED) model. UCED models are power system models that simulate the operation of a fleet of electricity generators, typically at hourly resolution subject to certain boundary conditions and operating constraints, in order to simulate the costs of meeting electricity demand, reserve margins

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Robert Wood, Matthew Wyant, Christopher S. Bretherton, Jasmine Rémillard, Pavlos Kollias, Jennifer Fletcher, Jayson Stemmler, Simone de Szoeke, Sandra Yuter, Matthew Miller, David Mechem, George Tselioudis, J. Christine Chiu, Julian A. L. Mann, Ewan J. O’Connor, Robin J. Hogan, Xiquan Dong, Mark Miller, Virendra Ghate, Anne Jefferson, Qilong Min, Patrick Minnis, Rabindra Palikonda, Bruce Albrecht, Ed Luke, Cecile Hannay, and Yanluan Lin

background aerosol and its variability because climate model experiments show that the strength of the global aerosol indirect effect is strongly sensitive to the preindustrial aerosol conditions ( Hoose et al. 2009 ; Ghan et al. 2013 ). F ig . 11. (a) MODIS visible image on 8 Aug 2009 (1240 UTC) showing rift feature containing small open cells and ship tracks in a shallow boundary layer about to cross Graciosa. Overlaid in transparency are the SEVIRI droplet effective radius retrievals showing

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