Search Results

You are looking at 31 - 40 of 517 items for :

  • Lidar observations x
  • Monthly Weather Review x
  • Refine by Access: All Content x
Clear All
Cornelius Hald, Matthias Zeeman, Patrick Laux, Matthias Mauder, and Harald Kunstmann

central Europe. Studying complex terrain is necessary to allow a wider range of opportunities for LES in real-world micrometeorological investigations. The simulated periods contain the transitions from nocturnal to daytime boundary layers and vice versa. The model results are evaluated against measurements of wind profiles using a triple Doppler-lidar setup. The first objective of this study is to analyze and evaluate model setups to achieve a stable model run in WRF-LES when using realistic boundary

Free access
Coltin Grasmick, Bart Geerts, David D. Turner, Zhien Wang, and T. M. Weckwerth

lidars aboard the UWKA. These observations are used in an effort to understand the lifting mechanism and effective source level for CI in LC regions. Specifically, we use the airborne lidar data to determine the actual vertical displacement for parcels at all possible source levels and compare this against the vertical distance to the parcel’s LFC. The UWKA completed a total of 20 transects across three convergent boundary zones leading this MCS. The first zone, referred to as Region I ( Fig. 2 ), is

Full access
Dana Mueller, Bart Geerts, Zhien Wang, Min Deng, and Coltin Grasmick

associated with a nocturnal MCS. This observational case study is unique in that it explores the evolution of the vertical structure of a bore. While other fixed, surface-based profiling observations depict a blend of distance and time evolution, this study uses airborne profiling lidar data, providing a series of quasi-instantaneous vertical transects, at a time resolution corresponding with the frequency of flight traverses across the bore (in this case 10–15 min). Another advantage to using an

Full access
Philip T. Bergmaier and Bart Geerts

of airborne radar and lidar observations of a New York Finger Lakes LE snow event. The observations are unique in the sense that airborne measurements of any kind within LE cloud bands have generally been obtained from bands over the much larger Great Lakes, primarily Lake Michigan (e.g., Passarelli and Braham 1981 ; Kelly 1982 , 1984 ; Braham 1990 ; Chang and Braham 1991 ; Braham et al. 1992 ; Braham and Dungey 1995 ; Kristovich et al. 2003 ; Schroeder et al. 2006 ; Yang and Geerts 2006

Full access
Ross N. Hoffman, Christopher Grassotti, Ronald G. Isaacs, Jean-Francois Louis, Thomas Nehrkorn, and Donald C. Norquist

DECEMBER 1990 HOFFMAN ET AL. 2513Assessment of the Impact of Simulated Satellite Lidar Wind and Retrieved 183 GHz Water Vapor Observations on a Global Data Assimilation SystemRoss N. HOFFMAN, CHRISTOPHER GRASSOTTI, RONALD G. ISAACS, JEAN-FRANCOIS LOUIS, AND THOMAS NEHRKORN Atmospheric and Environmental Research, Inc., Cambridge, Massachusetts DONALD C. NORQUISTGeophysics Laboratory, Air

Full access
Arnout Feijt and André van Lammeren

derivation of cloudproperties. Ground-based measurements from a lidar ceilometer and an infrared radiometer were combined withmeasurements of the NOAA Advanced Very High Resolution Radiometer and Meteosat satellite insmunents. Twocase studies ate presented: a case with streets of fair weather cumuli and a case with a weak cold front involvingcumulus, slratus, and cirrus clouds. From the combination of ground-based and satellite observations, a much betterdescription of the cloud field geomela'y, cloud

Full access
Steven E. Koch, Paul B. Dorian, R. Ferrare, S. H. Melfi, William C. Skillman, and D. Whiteman

, Laurel Maryland *Universities Space Research Association, NASA/Goddard Space Flight Center, Greenbelt, Maryland # NASA /Goddard Space Flight Center, Laboratory Jbr Terrestrial Physics, Greenbelt, Maryland (Manuscript received 16 April 1990, in final form 31 August 1990) ABSTRACT Detailed moisture observations from a ground-based Raman lidar and special radiosonde data of two disturbances associated with a dissipating gust front are presented. A synthesis of the

Full access
M. Weissmann, F. J. Braun, L. Gantner, G. J. Mayr, S. Rahm, and O. Reitebuch

. J. Geophys. Res. , 102 , 16663 – 16682 . Nyeki , S. , and Coauthors , 2002 : Airborne lidar and in-situ aerosol observations of an elevated layer, leeward of the European Alps and Apennines. Geophys. Res. Lett. , 29 . 1852, doi:10.1029/2002GL014897 . Rahm , S. , R. Simmet , and M. Wirth , 2003 : Airborne two micron coherent lidar wind profiles. Proc. 12th Coherent Laser Radar Conf., Bar Harbor, ME, 94–97 . Raymond , D. , and M. Wilkening , 1980 : Mountain

Full access
Jason A. Otkin, Daniel C. Hartung, David D. Turner, Ralph A. Petersen, Wayne F. Feltz, and Erik Janzon

periods with little manual intervention. Profile observations were created to emulate the Doppler wind lidar (DWL), microwave radiometer (MWR), and Atmospheric Emitted Radiance Interferometer (AERI) sensors. Observations were also created to emulate the state-of-the-art Raman lidar (RAM) system run operationally at the Department of Energy’s Atmospheric Radiation Measurement (ARM) site in north-central Oklahoma ( Goldsmith et al. 1998 ; Turner et al. 2000 , 2002 ); however, this sensor is currently

Full access
David B. Parsons, Melvyn A. Shapiro, R. Michael Hardesty, Robert J. Zamora, and Janet M. Intrieri

obtained from the Doppler lidar measurementswere combined with the equations of motion to derive perturbation fields of pressure and virtual potentialtemperature By. Our observations indicate that the circulations associated with this retrogressing dryline weredominated by hot, dry air riding over a westward moving denser, moist flow in a manner similar to a densitycurrent. Gravity waves were observed above the dryline interface. Previous observational and numerical studieshave shown that differential

Full access