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James D. Spinhirne, William D. Hart, and Dennis L. Hlavka

payload to be flown at an altitude, nominally19 km, well above the highest cirrus or other clouds.A special instrument complement on the ER-2 forcloud observations has been deployed in a sequence offield experiments. The basic instruments for the cloudradiation experiments are multispectral visible and infrared imaging radiometers and a lidar profiler. Theseinstruments and their application to cirrus cloud radiation field experiments are described in Spinhirne andHart (1990, hereafter SH). A summary

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Thomas J. Duck, James A. Whiteway, and Allan I. Carswell

important to stratospheric dynamics. In this study the gravity wave observations obtained with the lidar at Eureka are examined in detail. Data from the 1992/93–1997/98 wintertime campaigns are used, forming a large sample of 422 nights of observation. Using a statistical approach, the late-December gravity wave activity increases are highlighted. Building upon the results of Whiteway et al. (1997) , the statistical relationships between gravity wave energies, wind speeds, and critical-level filtering

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S. A. Ackerman, W. L. Smith, A. D. Collard, X. L. Ma, H. E. Revercomb, and R. O. Knuteson

FASCOD3 calculationsfor each angle incident on the cloud, for the purposesof this paper, FASCOD3 is used to calculate the nadirand zenith angle radiances, and the radiation field isthen assumed to be isotropic for the uplooking anddownlooking hemispheres. FASCOD3 is used to assigngaseous transmittance within the cloud. Examples of model simulations are presented below,which correspond to conditions observed during FIREII on 26 November 1991. Lidar observations indicateda cirrus cloud between

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Guido Visconti, Marco Verdecchia, and Giovanni Pitari

integrated for two years to study the evolution of the El Chich6n aerosolcloud in the stratosphere, starting about three months after the eruption. Initial conditions for the backscatteringratios are taken from airborne lidar measurements, while observations taken at Mauna Loa are used to estimatethe initial size distribution for the aerosols. Aerosols have been treated as a passive tracer, because the smallchanges in the stratospheric dynamics due to the aerosol interaction with solar and longwave

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Terry L. Clark, William D. Hall, Robert M. Kerr, Don Middleton, Larry Radke, F. Martin Ralph, Paul J. Neiman, and David Levinson

result, many of the derived fields required considerable interpolation and interpretation. More recently, remote sensing using the ground-based lidar of National Oceanic and Atmospheric Administration/Environmental Research Laboratories/Environmental Technology Laboratory (NOAA/ERL/ETL) has significantly improved the observations of such flow fields ( Neiman et al. 1988 ; Ralph et al. 1992 ; Ralph et al. 1997 ). Ralph et al. (1997) observed elevated regions of breaking internal gravity waves

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Pengfei Tian, Lei Zhang, Xianjie Cao, Naixiu Sun, Xinyue Mo, Jiening Liang, Xuetao Li, Xingai Gao, Beidou Zhang, and Hongbin Wang

mixed-type aerosols has not yet been statistically studied. In the present study, the aerosol optical and radiative properties of anthropogenic, mixed-type, and dust aerosols were studied using almost 3 years of simultaneous observations from a depolarization lidar and a sun photometer over an Aerosol Robotic Network (AERONET) site in Lanzhou, China. The observation site, aerosol data, and radiative calculations are introduced in section 2 , and the aerosol classification is discussed in section 3

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Greg M. McFarquhar, Andrew J. Heymsfield, James Spinhirne, and Bill Hart

, respectively, occurring approximately 50% of the time using a lidar operating at Chang-Li, Taiwan, at 25°N. Platt et al. (1998) also detected subvisible cirrus with visible and infrared optical depths as low as 0.01 in Kavieng, Papua, New Guinea, at 3°S in 1993 using a lidar. From near-global observations of optically thin cirrus during the Lidar In-space Technology Experiment, Winker and Trepte (1998) found layers of cirrus occurring in thin sheets near the tropical tropopause with thicknesses between

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Kenneth Sassen and Jennifer M. Comstock

cirrus clouds. Part II: Treatment of radiative properties. J. Atmos. Sci , 53 , 2967 – 2988 . Ou , S-C. , and K-N. Liou , 1995 : Ice microphysics and climatic temperature feedback. Atmos. Res , 35 , 127 – 138 . Platt , C. M. R. , 1973 : Lidar and radiometric observations of cirrus clouds. J. Atmos. Sci , 30 , 1191 – 1204 . Platt , C. M. R. , and A. C. Dilley , 1981 : Remote sensing of high clouds, Part IV, Optical properties of midlatitude and tropical cirrus. J. Atmos

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Tianfeng Chai, Ching-Long Lin, and Rob K. Newsom

. The above experiments recommend use of a big model domain covering sector-shaped HRDL data for real lidar data retrieval. d. Observational errors In contrast with the radial velocity provided for the previous ITEs, real lidar observations always contain errors. Lin et al. (2001) conducted sensitivity tests on observational errors of various amplitude and spatial correlation. With introduction of buffer zones, this issue must be reexamined. As quality control is routinely applied in

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Kathleen A. Edwards, Audrey M. Rogerson, Clinton D. Winant, and David P. Rogers

the lidar data ( Fig. 14a ). Where the lidar track would have cut across the model jump, the model height increased 59 m and speed decreased 2 m s −1 over 14 km ( Fig. 14c ). Collocated velocity observations were not available along the track, but SSM/I speeds ( Fig. 14b ) were available 40 km away from the lidar track. The layer speed estimate based on the SSM/I data decreased about 1 m s −1 over a horizontal distance similar to the model jump. The location of these features can be compared in

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