Convective and Orographically-Induced Precipitation Study (COPS), conducted in the Black Forest region in Southern Germany and Eastern France during the summer of 2007. From the 13 June to the 16 August 2007, the National Centre for Atmospheric Science (NCAS), Facility for Ground-based Atmospheric Measurement (FGAM) 1.5 mu m scanning Doppler lidar was deployed at Super Site R, Achern, in the Rhine Valley, in order to contribute to the extensive COPS observation campaign. The FGAM Doppler lidar system provides measurements of radial wind and aerosol backscatter in the layer 100-1500 m. Profiles of horizontal wind velocity are presented, these being derived from performing azimuth scans. Profiles of vertical velocity, its variance and skewness derived from the vertical scans are also presented and discussed in the paper. Knowledge of vertical velocity skewness is important for the understanding of the structure and origin of turbulent convection in the atmospheric boundary layer (ABL). The skewness of vertical velocity can provide a measure of the asymmetry in the distribution of vertical velocity perturbations within the ABL and can be estimated using the Doppler lidar. In addition, we investigate the behaviour of the boundary layer using data from the FGAM Doppler lidar and Automatic Weather Station (AWS), the University of Basilicata Raman lidar (BASIL) and the DLR's Poldirad C-band radar. A case study event on the 6th August 2007 is selected and investigations of possible causes of layers with positive and negative skewness are presented, along with comparisons with output from the National Center for Atmospheric Research (NCAR) Weather Research and Forecasting (WRF) model to assess the accuracy of the model output, including location and timing of rainfall onset.

WeatherVolume 65, Issue 2 p. 45-50 Research Article The land below the wind: Doppler LiDAR observations from the tropical rain forest of Sabah, Borneo, Malaysia Chris G. Collier, Chris G. Collier Centre for Environmental Systems Research, University of SalfordSearch for more papers by this authorFay Davies, Corresponding Author Fay Davies f.davies@salford.ac.uk Centre for Environmental Systems Research, University of SalfordCentre for Environmental Systems Research, Built & Human Environment Research Institute, School of Environment & Life Sciences, University of Salford, Salford, Greater Manchester, M5 4WT, UK.Search for more papers by this authorGuy N. Pearson, Guy N. Pearson Centre for Environmental Systems Research, University of SalfordSearch for more papers by this author Chris G. Collier, Chris G. Collier Centre for Environmental Systems Research, University of SalfordSearch for more papers by this authorFay Davies, Corresponding Author Fay Davies f.davies@salford.ac.uk Centre for Environmental Systems Research, University of SalfordCentre for Environmental Systems Research, Built & Human Environment Research Institute, School of Environment & Life Sciences, University of Salford, Salford, Greater Manchester, M5 4WT, UK.Search for more papers by this authorGuy N. Pearson, Guy N. Pearson Centre for Environmental Systems Research, University of SalfordSearch for more papers by this author First published: 26 January 2010 https://doi.org/10.1002/wea.429Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume65, Issue2February 2010Pages 45-50 RelatedInformation

The Convective and Orographically-Induced Precipitation Study, COPS, was conducted in the Black Forest region of Germany during the summer of 2007. Its aim was to advance the quality of forecasts of orographically induced convective precipitation by 4D observations and modelling. From the 13th June to the 16th August 2007, the Universities’ Facility for Atmospheric Measurement (UFAM) 1.5 micron scanning Doppler lidar, operated by the University of Salford, was deployed at Achern, Baden-Wurttemberg, Germany, in order to take part in the extensive COPS observation campaign. The University of Salford lidar system measures radial wind and aerosol backscatter from 105 m above the surface to the top of the boundary layer. Profiles of horizontal wind velocity are shown; these being derived from performing azimuth scans of 5 minute duration, approximately every 30 minutes. Between azimuth scans, the lidar pointed vertically. Profiles of vertical velocity, its variance and skewness are also shown. Knowledge of vertical velocity skewness is important as it can help understand the structure and origin of turbulent convection in the boundary layer. The skewness of vertical velocity can provide a measure of the asymmetry in the distribution of vertical velocity perturbations within the atmospheric boundary layer (ABL). In previous studies, under fair-weather conditions, when the ABL is heated from below, skewness profile tends to be positive throughout the ABL, while under cloudy conditions, the skewness profile can be affected by cloud processes and therefore predominantly negative. The behaviour of the boundary layer is investigated using data from the Salford University Doppler lidar, microwave radiometer and automatic weather station. In this paper, selected cases are compared and the similarities and differences are noted. Investigations of possible causes of layers of positive and negative skewness are presented, along with intercomparisons with radiosonde ascents from the Achern site.

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.

During the Convective and Orographically induced Precipitation Study (COPS), a scanning Doppler lidar was deployed at Achern, Baden-Wuttemberg, Germany from 13(th) June to 16(th) August 2007. Vertical velocity profiles ('rays') through the boundary layer were measured every 3 seconds with vertical profiles of horizontal wind velocity being derived from performing azimuth scans every 30 minutes. During Intense Observation Periods radiosondes were launched from the site. In this paper, a case study of convective boundary layer development on 15(th) July 2007 is investigated. Estimates of eddy dissipation rate are made from the vertically pointing lidar data and used as one input to the velocity-temperature co-variance equation to estimate sensible heat flux. The sensible heat flux values calculated from Doppler lidar data are compared with a surface based energy balance station and output from the Weather Research and Forecasting (WRF) model.

In this paper, observations by a ground-based vertically pointing Doppler lidar and sonic anemometer are used to investigate the diurnal evolution of boundary-layer turbulence in cloudless, cumulus and stratocumulus conditions. When turbulence is driven primarily by Surface heating, Such as in cloudless and cumulus-topped boundary layers, both the vertical velocity variance and skewness follow similar profiles, oil average, to previous observational studies of turbulence in convective conditions, with a peak skewness of around 0.8 in the upper third of the mixed layer. When the turbulence is driven primarily by cloud-top radiative cooling, Such as in the presence of nocturnal stratocumulus, it is found that the skewness is inverted in both sign and height: its minimum value of around -0.9 occurs in the lower third of the mixed layer. The profile of variance is consistent with it cloud-top cooling rate of around 30 W m(-2). This is also consistent with the evolution of the thermodynamic profile and the rate of growth of the mixed layer into the stable nocturnal boundary layer from above. In conditions where surface heating occurs simultaneously with cloud-top cooling, the skewness is found to be useful for diagnosing the source of the turbulence, 1,suggesting that long-term Doppler lidar observations would be valuable for evaluating boundary-layer parametrization schemes. Copyright (C) 2009 Royal Meteorological Society

Recent progress on the development of a long-range, high-resolution 3D active imaging sensor is described. Diffraction limited angular resolution of 20μrad and sub-metre down range resolution are demonstrated at stand-off ranges of 8km. A scanned single pixel arrangement was employed using an all-fiber coherent lidar operating in a chirp-pulse-compression mode. The monostatic antenna had an aperture of 150mm and the image was built up using a piezoelectric tip/tilt stage positioned prior to the final expansion of the beam. Transmit/receive multiplexing was achieved with a fiber optic circulator. Examples of recently acquired images consisting of 150x150 pixels with 1000, 30cm range cells per pixel at a stand-off range 8km are presented.

Recent developments in pulsed Doppler lidar technology for range-resolved aerosol and hard-target imaging applications are presented. Systems based upon CO2 and fiber-optic technologies at wavelengths of 10.6mum and 1.5mum respectively are described. Data are presented showing aspects of system and component development as well as recent field deployments.

ALADIN (standing for Atmospheric Laser Doppler Instrument), as a spaceborne Doppler wind lidar instrument, is intended to respond to the pressing need for an accurate wind field description at global scale for both meteorology and numerical weather prediction and climate applications. Such an active instrument will fulfill the gap existing between the present capability of sophisticated numerical models and the drastic lack of information they do require. It will also bring a full-size demonstration of the potential of spaceborne wind lidar in world meteorological and climate monitoring.

A monostatic pulsed CO2 Doppler lidar operating in a short-pulse (<1 μs), high-pulse-repetition-frequency (≳1 kHz), low-pulse energy (1–10 mJ) mode has been developed for Doppler and return-power measurements within the planetary boundary layer. The system has achieved near-quantum-limited performance, demonstrating a Doppler measurement capability to approximately 5 km with pulse energies of 1–2 mJ.

System considerations and the design of infrared coherent lidars utilizing tropospheric backscatter are discussed. Requirements regarding power measurement, Doppler measurement, antenna and laser energy considerations are addressed. A design for an improved CO2 laser source is proposed that meets these requirements and is compact and capable of unattended operation.

th August was selected after examination of the vertical velocity timeseries measured using Doppler lidar for that day showed what seemed to be a straightforward case of convective rainfall. The synoptic chart for this day didn't show any features to suggest otherwise. To confirm this, radiosonde data was examined and a convective boundary layer was present. From the radiosondes, it is possible to see convective conditions earlier, with stable, moist conditions later in the day. This is consistent with the passing of a rainfall event. An arrow indicates an inversion which seems to act as a 'lid' on the convection.