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Daniel K. Zhou, William L. Smith Sr., Xu Liu, Allen M. Larar, Stephen A. Mango, and Hung-Lung Huang

demonstration. Retrieval results of cloud and atmospheric properties from NAST-I observations are compared with coincident observations obtained from the nadir-pointing cloud physics lidar (CPL) and dropsondes, respectively. 2. Physical retrieval scheme a. Radiative transfer model and Jacobian matrix The radiance measurements within the short-wavelength region, where the observed radiance may be affected by reflected solar radiation, are typically not used during daytime observing conditions. The cloud

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Kevin Knupp

1. Introduction This paper examines the formation and evolution of an atmospheric internal bore that was initiated by a strong gust front within a developing (unsteady) nocturnal boundary layer (NBL). The complete evolutionary cycle, from a gust front to a bore to an eventual solitary wave pair, is examined with radar, profiler, and surface observations. The evolution of the NBL thermodynamic and wind profiles is also resolved with radar and atmospheric profiling measurements to relate

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Vijayakumar S. Nair, K. Krishna Moorthy, S. Suresh Babu, and S. K. Satheesh

the column. Generally, transported mineral dust has a mode radius of 0.5 μ m ( Hess et al. 1998 ). These particles occurring at higher levels produce the enhanced concentration in Fig. 15 and also lead to lowering of the values of α (deduced from the spectral AOD). These observations are also in line with the earlier report of Niranjan et al. (2007) , who, based on extensive profiling using a micropulse lidar at the east coast of Visakhapatnam, have shown the existence of elevated aerosol

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S. P. Alexander and A. R. Klekociuk

Abstract

We combine observations of optically-thin cirrus clouds made by lidar at Davis, Antarctica (69°S, 78°E) during 14 – 15 June 2011 with a microphysical retrieval algorithm to constrain the ice water content (IWC) of these clouds. The cirrus were embedded in a tropopause jet which flowed around a ridge of high pressure extending southwards over Davis from the Southern Ocean. Cloud optical depths were (0.082±0.001) and sub-visual cirrus were present during 11% of the observation period. The macrophysical cirrus cloud properties obtained during this case study are consistent with those previously reported at lower latitudes. MODIS satellite imagery and AIRS surface temperature data are used as inputs into a radiative transfer model in order to constrain the IWC and ice water path of the cirrus. The derived cloud IWC is consistent with in-situ observations made at other locations but at similarly cold temperatures. The optical depths derived from the model agree with those calculated directly from the lidar data. This study demonstrates the value of a combination of ground-based lidar observations and a radiative transfer model in constraining microphysical cloud parameters which could be utilised at locations where other lidar measurements are made.

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Qingfang Jiang and James D. Doyle

of flight-level data, scanning aerosol backscatter lidar (SABL) imagery, and global positioning system (GPS) dropsonde data. Section 5 includes spectral analysis and estimation of vertical fluxes and turbulent kinetic energy using aircraft in situ measurements. In section 6 , the Coupled Ocean– Atmosphere Mesoscale Prediction System (COAMPS) real-data simulation is compared with observations. The role of multiscale terrain in wave breaking is further investigated in section 7 through a

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James D. Doyle, Vanda Grubišić, William O. J. Brown, Stephan F. J. De Wekker, Andreas Dörnbrack, Qingfang Jiang, Shane D. Mayor, and Martin Weissmann

Jet Stream Project, both of which took place in the early 1950s ( Holmboe and Klieforth 1957 ; Grubišić and Lewis 2004 ), were the first coordinated research efforts focused on observing topographically forced phenomena and documented several research aircraft penetrations of rotors and associated turbulence ( Holmboe and Klieforth 1957 ). The relatively rare in situ research aircraft encounters with rotors ( Lester and Fingerhut 1974 ), along with occasional lidar observations of downslope

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Quanxin Xia, Ching-Long Lin, Ronald Calhoun, and Rob K. Newsom

synthesized observations and predicted variables are generated by the model, the model error cannot be accounted for in the ITE. Thus, the ITE tends to yield optimistic results. In the JU2003 field campaign, dual Doppler lidars were deployed to measure fluid radial velocities in the urban boundary layer. The deployment of the two lidars was coordinated so that the second lidar could provide the missing cross-beam radial velocity data by scanning from an orthogonal or nearly orthogonal direction. This

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Bowen Zhou and Fotini Katopodes Chow

flow, which is in the northwest direction ~300°. This synoptic flow is responsible for the daytime down-valley flow because of the channeling effect of the valley ( WHP09 ). The source of the easterly flow is unclear because of the limited horizontal scan range of the lidar. Radiosondes could have captured this flow, but none were launched that night. The 3D simulations, on the other hand, have the advantage of complete spatial and temporal coverage. Once validated against observations, we can use

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Tetsu Sakai, Narihiro Orikasa, Tomohiro Nagai, Masataka Murakami, Kenichi Kusunoki, Kazumasa Mori, Akihiro Hashimoto, Takatsugu Matsumura, and Takashi Shibata

on the particle size, shape, and chemical composition. For example, based on field observations ( Ferrare et al. 2001 ; Anderson et al. 2000 ) and theoretical calculations ( Ackermann 1998 ), the values for submicrometer-sized aerosols are generally higher than approximately 30 sr. Meanwhile, the values for the supermicrometer-sized ice crystals and water droplets are generally lower than 30 sr ( Sakai et al. 2003 ). Since the lidar was vertically pointing in this study, the δ and S values

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T. J. Swissler, P. Hamill, M. Osborn, P. B. Russell, and M. P. McCormick

.4 months, versus 10.4 and7.9 months for Nr>o. ls and Nr>o.25. The modeling technique is used to derive a time series of dustsonde-inferred peak backscatter mixingratio, which agrees very well with the lidar-measured series. The best overall agreement for 1974-80 isachieved with a mixture of refractive indices corresponding to aqueous sulfuric acid at about 210 K withan acid-weight fraction between 0.6 and 0.85.1. Introduction Experimental observations of the stratosphericaerosol layer have

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