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Kenneth Sassen, Zhien Wang, C. M. R. Platt, and Jennifer M. Comstock

, U. , and E. Roeckner , 1995 : Influence of cirrus cloud radiative forcing on climate and climate sensitivity in a general circulation model. J. Geophys. Res. , 100 , 16305 – 16323 . Mitchell , D. L. , 2002 : Effective diameter in radiative transfer: General definition, applications, and limitations. J. Atmos. Sci. , 59 , 2330 – 2346 . Platt , C. M. R. , 1973 : Lidar and radiometric observations of cirrus clouds. J. Atmos. Sci. , 30 , 1191 – 1204 . Platt , C. M. R. , and

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Kenneth Sassen, Likun Wang, David O’C. Starr, Jennifer M. Comstock, and Markus Quante

with height was related to directional shear, as was earlier proposed by Oddie (1959) . Observations by Yagi (1969) located the cirrus uncinus head in a turbulent layer with a dry adiabatic lapse rate, which allowed for its more convective appearance, while the fall streaks were situated in the stable layer below. From more recent aircraft, lidar, and radar studies, we know that a variety of structures (i.e., cloud microphysical inhomogeneities) occur in cirrus clouds on both the cloud scale

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Robin J. Hogan

a is the radius of the particle ( van de Hulst 1957 ; Hogan 2006 , hereafter H06 ). For typical ground-based lidar observations of ice and liquid clouds and spaceborne lidar observations of ice clouds and aerosols, the field of view is such that these small-angle forward-scattered photons may remain within the field of view of the detector and contribute to the apparent backscatter, whereas photons that experience wide-angle scattering will typically be transported outside the field of view

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Likun Wang and Kenneth Sassen

or a secondary generating cell driven by strong evaporation was the reason for the turbulence eddies. Jo et al. (2003) reported high-resolution W-band Doppler radar observations revealing strong downward mean Doppler velocities (4–5 m s −1 ) in the cirrus mammatus cores and compensating upward (1–2 m s −1 ) motions in the peripheries. However, more climatological research describing cirrus mammata has not been attempted until this study, which combines advanced lidar and Doppler radar

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I. Schlimme, A. Macke, and J. Reichardt

real cirrus cloud structure. Therefore we decided to employ 2D volume extinction coefficient data obtained with Raman lidar to study inhomogeneous cirrus clouds. In addition to the advantage of profiling the atmospheric column, Raman lidar measurements of cirrus clouds are available in significantly larger numbers than aircraft observations. At present, only molecular backscatter lidars [Raman lidar and high spectral resolution lidar; see Ansmann (2002) for a detailed discussion of molecular

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Rob K. Newsom and Robert M. Banta

f = 0.017 Hz, which corresponds to a wave period of about 60 s. b. Lidar observations Scorer (1997) noted that billows always occur several at a time and imagery from the lidar clearly bears this out. Figure 1 shows six representative sequential vertical slice scans of υ r taken by the lidar during the wave period. These six scans were selected from a longer sequence of 33 individual scans, which was initiated at 0525 and terminated at 0542 UTC. During this time, the lidar performed

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Masanori Saito and Ping Yang

/plates have specific orientations with the maximum dimensions ranging from D OIC,min = 100 μ m to D OIC,max = 3000 μ m, and have random orientations beyond the size range. Under realistic atmospheric conditions, hexagonal columns and plates may not be perfectly horizontally orientated but quasi-horizontally orientated. Noel and Sassen (2005) found that the tilting angle θ tilt of HOPs follows a Gaussian distribution based on ground-based scanning lidar observations. Therefore, we assume the

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P.B. Russell, M.P. McCormick, T.J. Swissler, W.P. Chu, J.M. Livingston, W.H. Fuller, J.M. Rosen, D.J. Hofmann, L.R. McMaster, D.C. Woods, and T.J. Pepin

advantages foruse in satellite studies: 1) it can obtain data abovelow- and middle-level clouds; 2) it can move rapidlyto satellite sensing locations; and 3) it can sample apath similar to that viewed by the satellite. In theseexperiments the lidar aircraft flew along the trapezoidal paths shown in Fig. 1 to allow for the uncertainty in satellite position (and hence in limb path)prior to the observations. The lidar was fired vertically upward, summingshots to form a vertical data profile representing

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Kenneth Sassen, David O'C. Starr, and Taneil Uttal

short ranges (<8 kin). During the 8March 1985 case study selected from the Lidar CirrusII project, the aircraft was flown parallel to the flightlevel wind in order to allow the intercomparison ofaircraft track data with remote sensing height-time(HTI) displays, as the sampled cloud volumes advectedoverhead with time. Doppler radar observations werecollected as single 0.15-s sweeps at 30-s intervals in thezenith direction during a break between aircraft missions, and as a series of Velocity

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C. M. R. Platt

backscatter peak of the scatteringphase function. Such a study is underway at present. REFERENCESAllen, R. J., and C. M. R. Platt, 1977: Lidar for multiple backscattering and depolarization observations. Appl. Opt., 16, 3193-3199.Davis, P. A., 1971: Applications of an airborne ruby lidar dhfi?g a BOMEX program of cirrus observations. J. Appl. Meteor., 10, 1314-1323.Deirmendjian, P., 1964: Scattering and polarization properties of water clouds and hazes in the visible and infrared

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