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Reginald J. Hill, W. Alan Brewer, and Sara C. Tucker

1. Introduction The National Oceanic and Atmospheric Administration (NOAA)/Earth System Research Laboratory (ESRL) has developed two coherent Doppler lidars to study atmospheric boundary layer dynamics (see Grund et al. 2001 ; Brewer et al. 1998 ). Typically these systems perform low–elevation angle scans to determine wind speed and direction and to quantify turbulence with high temporal and vertical resolution. This is accomplished by operating with a high pulse-repetition frequency and

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Simon P. Alexander and Toshitaka Tsuda

. P. , Tsuda T. , and Furumoto J. , 2007 : Effects of atmospheric stability on wave and energy propagation in the troposphere. J. Atmos. Oceanic Technol. , 24 , 602 – 615 . 10.1175/JTECH2046.1 Angevine, W. M. , and Ecklund W. L. , 1994 : Errors in radio acoustic sounding of temperature. J. Atmos. Oceanic Technol. , 11 , 837 – 842 . 10.1175/1520-0426(1994)011<0837:EIRASO>2.0.CO;2 Angevine, W. M. , Avery S. K. , Ecklund W. L. , and Carter D. A. , 1993 : Fluxes of heat and

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Rod Frehlich, Yannick Meillier, and Michael L. Jensen

-modulated continuous wave radar for studying planetary boundary layer morphology. Radio Sci. , 30 , 75 – 88 . 10.1029/94RS01937 Esau, I. N. , and Zilitinkevich S. S. , 2006 : Universal dependencies between turbulent and mean flow parameters in stably and neutrally stratified planetary boundary layers. Nonlinear Processes Geophys. , 13 , 135 – 144 . 10.5194/npg-13-135-2006 Frehlich, R. , 1997 : Effects of wind turbulence on coherent Doppler lidar performance. J. Atmos. Oceanic Technol. , 14 , 54

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Ronny Engelmann, Ulla Wandinger, Albert Ansmann, Detlef Müller, Egidijus Žeromskis, Dietrich Althausen, and Birgit Wehner

below 100-m height (e.g., Buzorius et al. 1998 ). Recently, this technique has also been applied on an aircraft near the ocean surface ( Buzorius et al. 2006 ). In situ measurements near the ground are representative for relatively small areas and can be used for describing local fluxes from very specific sources, for example, a forest, a field, or an urban site. In contrast, flux profile observations throughout the PBL are representative of a much larger scale and can be used for the improvement

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P. C. S. Devara, P. E. Raj, K. K. Dani, G. Pandithurai, M. C. R. Kalapureddy, S. M. Sonbawne, Y. J. Rao, and S. K. Saha

the incident light wave is plane polarized with the plane of polarization parallel or perpendicular to the scattering plane, scattered radiation will contain both parallel and perpendicular polarized components. This is mainly because of the anisotropy of aerosol scattering. If the individual aerosols are assumed to be isotropic (spherical), the polarization components along the principal direction are equal, and the components in all other directions vanish. This implies that for isotropic

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Danny E. Scipión, Phillip B. Chilson, Evgeni Fedorovich, and Robert D. Palmer

of the lower atmosphere is the boundary layer radar (BLR). The term BLR is generally applied to a class of pulsed Doppler radar that transmits radio waves vertically, or nearly vertically, and receives Bragg backscattered signals from refractive index fluctuations of the optically clear atmosphere. The operating frequency of this type of radar is typically near 1 GHz. Therefore, the Bragg scale is such that BLRs are sensitive to turbulent structures that have spatial scales near 15 cm. Enhanced

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B. L. Cheong, R. D. Palmer, T-Y. Yu, K-F. Yang, M. W. Hoffman, S. J. Frasier, and F. J. Lopez-Dekker

1. Introduction Very high-frequency (VHF) and ultrahigh-frequency (UHF) profiling radars have been used widely in both the operational and research arenas for observations of the structure and dynamics of the atmosphere. In particular, this type of radar has proven important for studies of turbulence, momentum fluxes, and gravity waves (e.g., Röttger and Larsen 1990 ; Gage 1990 ; and references therein). One of the more common techniques for obtaining profiles of the three-dimensional wind

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Edwin F. Campos, Wayne Hocking, and Frédéric Fabry

parameters of this radar are given in Table 1 . To correct for precipitation attenuation at the X band, we collected measurements of raindrop sizes near the ground. For this, we use a Precipitation Occurrence Sensor System (POSS; described by Sheppard 1990 ), which was collocated with the VPDR and the VHF radars. POSS is a bistatic, X-band (10.5 GHz, 2.85 cm), continuous-wave Doppler radar. This sensor points upward and detects precipitation particles in its sampling volume, which is located only a few

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Daniela Nowak, Dominique Ruffieux, Judith L. Agnew, and Laurent Vuilleumier

instruments, a Vaisala CT25K ceilometer and a 78-GHz frequency-modulated continuous-wave (FMCW) cloud radar were installed and operated at the measurement site from mid-November 2003 to mid-February 2004. In this paper a method to determine fog and low stratiform cloud layers from cloud radar and ceilometer data is described. The efficacy of the combination of the two systems during the winter 3-month period is assessed. In section 2 , the instruments and the method of the determination of cloud or fog

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Thierry Leblanc, I. Stuart McDermid, and Robin A. Aspey

equivalent to a measure of upper-tropospheric water vapor. Figure 3b is identical to Fig. 3a , but for the total column (i.e., integrated between the top of the troposphere and the ground). Despite high variability, which makes the detection of any seasonal cycles difficult, the summer months seem to consistently be wetter (>20 mm) than the rest of year (<10 mm). This tendency is confirmed on Fig. 3c where the total column obtained from radiosonde, lidar, and the collocated Water Vapor Mm-Wave

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