Towards improved turbulence estimation with Doppler wind lidar velocity-azimuth display (VAD) scans

• Published in: Atmospheric measurement techniques Vol. 13; no. 8; pp. 4141 - 4158
• Main Authors: Wildmann, Norman, Päschke, Eileen, Roiger, Anke, Mallaun, Christian
• Format: Journal Article
• Language: English
• Published: Katlenburg-Lindau Copernicus GmbH 04.08.2020; Copernicus Publications
• Subjects: Advection; Aerodynamics; Aircraft; Analysis; Anemometers; Atmospheric boundary layer; Azimuth; Boundary layer meteorology; Boundary layers; Corrections; Doppler sonar; Elevation angle; Energy (Physics); Experiments; Greenhouse gases; In situ measurement; Kinetic energy; Lidar; Lidar measurements; Masts; Meteorology; Methods; Observatories; Optical radar; Remote sensing; Research aircraft; Retrieval; Sonic anemometers; Turbulence; Turbulence (Fluid dynamics); Turbulence measurement; Turbulence parameters; Velocity; Weather; Wind measurement; Germany
• ISSN: 1867-8548; 1867-1381; 1867-8548
• DOI: 10.5194/amt-13-4141-2020

The retrieval of turbulence parameters with profiling Doppler wind lidars (DWLs) is of high interest for boundary layer meteorology and its applications. DWLs provide wind measurements above the level of meteorological masts while being easier and less expensive to deploy. Velocity-azimuth display (VAD) scans can be used to retrieve the turbulence kinetic energy (TKE) dissipation rate through a fit of measured azimuth structure functions to a theoretical model. At the elevation angle of 35.3.sup." it is also possible to derive TKE. Modifications to existing retrieval methods are introduced in this study to reduce errors due to advection and enable retrievals with a low number of scans. Data from two experiments are utilized for validation: first, measurements at the Meteorological Observatory Lindenberg-Richard-Aßmann Observatory (MOL-RAO) are used for the validation of the DWL retrieval with sonic anemometers on a meteorological mast. Second, distributed measurements of three DWLs during the CoMet campaign with two different elevation angles are analyzed. For the first time, the ground-based DWL VAD retrievals of TKE and its dissipation rate are compared to in situ measurements of a research aircraft (here: DLR Cessna Grand Caravan 208B), which allows for measurements of turbulence above the altitudes that are in range for sonic anemometers.