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Kenneth Sassen and Gregory C. Dodd

than those possible from a pseudoadiabatic processinvolving nucleation at water saturation. Finally, to determine whether polarization lidar observations canidentify haze particles in cirrus generating regions, as has been suggested by recent studies, Mie scatteringsimulations were performed for the properties of the model-generated haze particles.1. Introduction In a previous study (Sassen and Dodd 1988), amixed-phase hydrometeor growth model was appliedto explaining the glaciation of a highly

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Timothy D. Crum and Roland B. Stull

atmospheric entrainment zone, an interfacial layer between the convective boundarylayer and the stable air aloft, is studied using coincident high resolution aircraft and lidar observations obtainedduring Boundary Layer Experiment-1983 in Oklahoma. Humidity as measured by a fast-response Lyman alphahumidiometer is used as a tracer to estimate the amonnt of surface-layer origin air reaching various heights inthe entrainment zone. Two approaches are taken to describe the humidity structure of the

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Ching-Long Lin, Tianfeng Chai, and Juanzhen Sun

), to reveal organized streak structures over flat terrain. Cooper et al. (1997) and Hagelberg et al. (1998) used lidar to identify multiscale Rayleigh–Bernard-like cells in the surface layer of a marine ABL. Nevertheless, three-dimensional (3D) wind vector and temperature data, required for understanding atmospheric flows, are not observed by Doppler radar or lidar. In recent years, new techniques have been developed to merge limited observations with dynamic models to derive more complete

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F. Martin Ralph, Paul J. Neiman, Teddie L. Keller, David Levinson, and Len Fedor

, and conditions were conducive to wave trapping, it is reasonable to conclude that the clouds marked trapped lee waves. b. Observations of nonstationarity Because the lidar receives strong backscatter from clouds, they appear clearly in plots of backscatter intensity from RHI scans oriented roughly perpendicular to the wave clouds ( Fig. 3 ). Two types of clouds are evident in this data. At a lower altitude (near 3.7 km AGL) are a series of clouds marking the trapped lee waves, and at a much higher

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Graeme L. Stephens, Si-Chee Tsay, Paul W. Stackhouse Jr., and Piotr J. Flatau

shown in the previous study ofAckerman and Stephcns (1987) that the albcdo is telatively insensitive to p and this parameter is set to thevalue of 2 in the remaining analyses.a. Platt ~ LIRAD observations The observations reported by Platt and Harshvardhan ( 1988 ) are employed here to select the values ofre that are used in parameterizations described above.Figure 4 shows the values of Otabs derived from a seriesof lidar-radiometer measurements (LII~D) (e.g., Plattet al. 1987): The additional

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Ivy Tan and Trude Storelvmo

. a. Global CALIOP observations of supercooled cloud fractions Global satellite observations of cloud phase were obtained by NASA’s Cloud–Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument. CALIOP is a dual-wavelength (532 nm, 1064 nm), 3°-off-nadir-viewing (at the present) polarization lidar (532-nm beam polarized) onboard the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations ( CALIPSO ) satellite. Launched in 28 April 2006, CALIOP flies in a sun-synchronous polar

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Ronald B. Smith, Steven Skubis, James D. Doyle, Adrian S. Broad, Christoph Kiemle, and Hans Volkert

complex array of quasi-periodic waves. In this model, the dominant wavelength of about 14 km becomes evanescent, or nearly so, in layer 2. Its downstream wavenumber component k = 0.00044 m −1 is slightly greater than N 2 / U 2 ( Table 1 ). In the evanescent layer, there is no phase tilt and the amplitude decays markedly, overpowering the effect of decreasing density. This decay and lack of tilt agrees with the aircraft and lidar observations. As expected, well-developed lee waves are also seen in

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Kenneth Sassen, Arlen W. Huggins, Alexis B. Long, Jack B. Snider, and Rebecca J. Meitín

dual-channel microwave radiometer, a polarization lidar, and a Ka-bandDoppler radar. These data are supplemented by upwind, valley-based C-band Doppler radar observations, whichprovided a considerably larger-scale view of the storm. In general, storm properties above the barrier were either dominated by barrierqevel orographic clouds orpropagating mesoscale cloud systems. The orographic cloud component consisted of weakly (-3- to -10-C)supercooled liquid water (SLW) clouds in the form of an

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Kenneth Sassen and James R. Campbell

Cirrus Experiment (ICE) ( Raschke et al. 1990 ). As part of our participation in Project FIRE, we began in 1987 supporting the extended time observations (ETO) component by collecting polarization lidar and passive radiometric data from high clouds at the University of Utah Facility for Atmospheric Remote Sensing (FARS) during times of Geostationary Operational Environmental Satellite (GOES) and polar-orbiting satellite local imagery. The nature of this unique long-term dataset is reviewed in

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Roni Avissar, Edwin W. Eloranta, Kemal Gürer, and Gregory J. Tripoli

designed for that purpose and, therefore, no perfect dataset is currently available. Yet during a few days of the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), volume-imaging lidar (VIL) and simultaneous observations of land-surface heat fluxes, atmospheric profiles of wind, temperature, and specific humidity were carried out. While not ideal, this dataset contains interesting information worth comparing with LES outputs. The research described in this

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