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W. R. Peltier and J. F. Scinocca

15DECEMBER 1990 W.R. PELTIER AND J. F. SCINOCCA 2853The Origin of Severe Downslope Windstorm Pulsations W. R. PELTIER AND J. F. SCINOCCA Department of Physics, University of Toromo, Toronto, Ontario, Canada (Manuscript received 4 August 1989, in final form 15 March 1990) ABSTRACT Recently reported Doppler lidar observations of the downslope component of flow velocity made during theoccurrence of a

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R. M. Worthington, A. Muschinski, and B. B. Balsley

relationship relative to [a] region of balloon ascents, or to the antenna beam of a wind profiler.” If wind-profiling radars and lidars, worldwide, are installed in similar locations relative to mountains, the resulting phase relation to mountain waves, and the effect on W , might be similar. The averaging timescale for W studied here, where VHF radar validation is the aim, is typically years—in fact as long as possible, since W ≈ 0 averaged over many years and worldwide is necessary, but not

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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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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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Marcus Klingebiel, Heike Konow, and Bjorn Stevens

Abstract

Mass flux is a key quantity in parameterizations of shallow convection. To estimate the shallow convective mass flux as accurately as possible, and to test these parameterizations, observations of this parameter are necessary. In this study, we show how much the mass flux varies and how this can be used to test factors that may be responsible for its variation. Therefore, we analyze long term Doppler radar and Doppler lidar measurements at the Barbados Cloud Observatory over a time period of 30 months, which results in a mean mass flux profile with a peak value of 0.03 kg m−2 s−1 at an altitude of ~730 m, similar to observations from Ghate et al. (2011) at the Azores Islands. By combining Doppler radar and Doppler lidar measurements, we find that the cloud base mass flux depends mainly on the cloud fraction and refutes an idea based on large eddy simulations, that the velocity scale is in major control of the shallow cumulus mass flux. This indicates that the large scale conditions might play a more important role than what one would deduce from simulations using prescribed large-scale forcings.

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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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