An Analysis of the Performance of the UFAM Pulsed Doppler Lidar for Observing the Boundary Layer

2009 ◽  
Vol 26 (2) ◽  
pp. 240-250 ◽  
Author(s):  
Guy Pearson ◽  
Fay Davies ◽  
Chris Collier

Abstract The performance of the 1.5-μm pulsed Doppler lidar, operated by the U.K. Universities Facility for Atmospheric Measurement (UFAM) over a 51-day continuous and unattended field deployment in southern England, is described and analyzed with a view to demonstrating the capabilities of the system for remote measurements of aerosols and velocities in the boundary layer. A statistical assessment of the vertical pointing mode in terms of the availability and errors in the data versus range is presented. Examples of lidar data are compared to theoretical predictions, radiosondes, the UFAM radar wind profiler, and an ultrasonic anemometer.

2016 ◽  
Vol 162 (3) ◽  
pp. 503-522 ◽  
Author(s):  
Meng Huang ◽  
Zhiqiu Gao ◽  
Shiguang Miao ◽  
Fei Chen ◽  
Margaret A. LeMone ◽  
...  

2009 ◽  
Vol 26 (4) ◽  
pp. 673-688 ◽  
Author(s):  
Sara C. Tucker ◽  
Christoph J. Senff ◽  
Ann M. Weickmann ◽  
W. Alan Brewer ◽  
Robert M. Banta ◽  
...  

Abstract The concept of boundary layer mixing height for meteorology and air quality applications using lidar data is reviewed, and new algorithms for estimation of mixing heights from various types of lower-tropospheric coherent Doppler lidar measurements are presented. Velocity variance profiles derived from Doppler lidar data demonstrate direct application to mixing height estimation, while other types of lidar profiles demonstrate relationships to the variance profiles and thus may also be used in the mixing height estimate. The algorithms are applied to ship-based, high-resolution Doppler lidar (HRDL) velocity and backscattered-signal measurements acquired on the R/V Ronald H. Brown during Texas Air Quality Study (TexAQS) 2006 to demonstrate the method and to produce mixing height estimates for that experiment. These combinations of Doppler lidar–derived velocity measurements have not previously been applied to analysis of boundary layer mixing height—over the water or elsewhere. A comparison of the results to those derived from ship-launched, balloon-radiosonde potential temperature and relative humidity profiles is presented.


2017 ◽  
Vol 56 (9) ◽  
pp. 2441-2454 ◽  
Author(s):  
Larry K. Berg ◽  
Rob K. Newsom ◽  
David D. Turner

AbstractOne year of coherent Doppler lidar data collected at the U.S. Department of Energy’s Atmospheric Radiation Measurement site in Oklahoma was analyzed to provide profiles of vertical velocity variance, skewness, and kurtosis for cases of cloud-free convective boundary layers. The variance was normalized by the Deardorff convective velocity scale, which was successful when the boundary layer depth was stationary but failed in situations in which the layer was changing rapidly. In this study, the data are sorted according to time of day, season, wind direction, surface shear stress, degree of instability, and wind shear across the boundary layer top. The normalized variance was found to have its peak value near a normalized height of 0.25. The magnitude of the variance changes with season, shear stress, degree of instability, and wind shear across the boundary layer top. The skewness was largest in the top half of the boundary layer (with the exception of wintertime conditions). The skewness was also found to be a function of the season, shear stress, and wind shear across the boundary layer top. Like skewness, the vertical profile of kurtosis followed a consistent pattern, with peak values near the boundary layer top. The normalized altitude of the peak values of kurtosis was found to be higher when there was a large amount of wind shear at the boundary layer top.


2014 ◽  
Vol 31 (2) ◽  
pp. 302-325 ◽  
Author(s):  
Howard B. Bluestein ◽  
Jana B. Houser ◽  
Michael M. French ◽  
Jeffrey C. Snyder ◽  
George D. Emmitt ◽  
...  

Abstract During the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2), in the spring of 2010, a mobile and pulsed Doppler lidar system [the Truck-Mounted Wind Observing Lidar Facility (TWOLF)] mounted on a truck along with a mobile, phased-array, X-band Doppler radar system [Mobile Weather Radar–2005 X-band, phased array (MWR-05XP)] was used to complement Doppler velocity coverage in clear air near the radar–lidar facility and to provide high-spatial-resolution vertical cross sections of the Doppler wind field in the clear-air boundary layer near and in supercells. It is thought that the magnitude and direction of vertical shear and possibly the orientation and spacing of rolls in the boundary layer have significant effects on both supercell and tornado behavior; MWR-05XP and TWOLF can provide data that can be used to measure vertical shear and detect rolls. However, there are very few detailed, time-dependent and spatially varying observations throughout the depth of the boundary layer of supercells and tornadoes. This paper discusses lidar and radar data collected in or near six supercells. Features seen by the lidar included gust fronts, horizontal convective rolls, and small-scale vortices. The lidar proved useful at detecting high-spatial-resolution, clear-air returns at close range, where the radar was incapable of doing so, thus providing a more complete picture of the boundary layer environment ahead of supercells. The lidar was especially useful in areas where there was ground-clutter contamination. When there was precipitation and probably insects, and beyond the range of the lidar, where there was no ground-clutter contamination, the radar was the more useful instrument. Suggestions are made for improving the system and its use in studying the tornado boundary layer.


2017 ◽  
Author(s):  
Igor N. Smalikho ◽  
Viktor A. Banakh

Abstract. The method and results of lidar studies of spatiotemporal variability of wind turbulence in the atmospheric boundary layer are reported. The measurements were conducted by a Stream Line pulsed coherent Doppler lidar with the use of conical scanning by a probing beam around the vertical axis. Lidar data are used to estimate the kinetic energy of turbulence, turbulent energy dissipation rate, integral scale of turbulence, and momentum fluxes. The dissipation rate was determined from the azimuth structure function of radial velocity within the inertial subrange of turbulence. When estimating the kinetic energy of turbulence from lidar data, we took into account the averaging of radial velocity over the sensing volume. The integral scale of turbulence was determined on the assumption that the structure of random irregularities of the wind field is described by the von Karman model. The domain of applicability of the used method and the accuracy of estimation of turbulence parameters were determined. Turbulence parameters estimated from Stream Line lidar measurement data and from data of a sonic anemometer were compared.


2009 ◽  
Vol 3 (1) ◽  
pp. 138-146 ◽  
Author(s):  
P.W. Chan

The Hong Kong Observatory (HKO) introduced a Doppler LIDAR to the Hong Kong International Airport (HKIA) in 2002, the first LIDAR for aviation alerting services in the world. Since then, HKO has developed a number of weather products based on the LIDAR’s velocity and backscatter power data. LIDAR is found to provide crucial information in a wide variety of aviation applications. This paper gives a review of the experience in Hong Kong in the development of aviation-related weather products using the LIDAR data. Applications include: automatic windshear alerting from the HKO-developed glide-path scans, detection of low-level turbulence, 2D wind retrieval for intense convective events from LIDAR-radar dual Doppler analysis, 3D wind retrieval from a single LIDAR for terrain-disrupted airflow, visibility map based on backscatter power distribution in conical scans, and mixing-height monitoring in vertical scans.


2017 ◽  
Vol 10 (11) ◽  
pp. 4191-4208 ◽  
Author(s):  
Igor N. Smalikho ◽  
Viktor A. Banakh

Abstract. The method and results of lidar studies of spatiotemporal variability of wind turbulence in the atmospheric boundary layer are reported. The measurements were conducted by a Stream Line pulsed coherent Doppler lidar (PCDL) with the use of conical scanning by a probing beam around the vertical axis. Lidar data are used to estimate the kinetic energy of turbulence, turbulent energy dissipation rate, integral scale of turbulence, and momentum fluxes. The dissipation rate was determined from the azimuth structure function of radial velocity within the inertial subrange of turbulence. When estimating the kinetic energy of turbulence from lidar data, we took into account the averaging of radial velocity over the sensing volume. The integral scale of turbulence was determined on the assumption that the structure of random irregularities of the wind field is described by the von Kármán model. The domain of applicability of the used method and the accuracy of the estimation of turbulence parameters were determined. Turbulence parameters estimated from Stream Line lidar measurement data and from data of a sonic anemometer were compared.


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