DOI: 10.25592/uhhfdm.11394
title: Doppler lidar mean wind profiles from VAD scans during FESSTVAL 2021

description: <strong>Abstract:</strong> This data set contains vertical profiles of the mean wind vector derived from Doppler lidar measurements between June 12 and July 19 2021 at the Grenzschichtmessfeld (GM) Falkenberg (<em><strong>sups_rao_dlidvad00</strong></em>) and between May 17 and July 15 2021 at the Meteorological Observatory Lindenberg – Richard-Aßmann-Observatory (<em><strong>fval_tub_dlidvad00</strong></em>) during the Field Experiment on Sub-mesoscale Spatio-Temporal Variability in Lindenberg (FESSTVaL). The GM Falkenberg as part of the Lindenberg Meteorological Observatory – Richard-Aßmann-Observatory are operated by the German national meteorological service (Deutscher Wetterdienst, DWD). The Doppler lidar system operated at the GM site was kindly provided by Technische Universität Berlin, Institute for Ecology, Chair of Climatology. Both, level 1 and level 2 data are provided. <strong>TableOfContents:</strong> <em><strong>level1:</strong></em> <strong>sups_rao_dlidvad00</strong>: sensor azimuth angle; attenuated backscatter coefficient; spectral width of detected signal; radial velocity of scatterers away from instrument (doppler velocity); error of doppler velocity; backscatter intensity; range bands; zenith angle <strong>fval_tub_dlidvad00</strong>: sensor azimuth angle; attenuated backscatter coefficient; radial velocity of scatterers away from instrument (doppler velocity); error of doppler velocity; backscatter intensity; range bands; zenith angle <em><strong>level2:</strong></em> wind speed; wind direction; eastward wind component u; northward wind component v; upward air velocity w; wind speed uncertainty; wind direction uncertainty; eastward wind component uncertainty; northward wind component uncertainty; upward air velocity uncertainty; wind quality flag; eastward wind component quality flag; northward wind component quality flag; upward air velocity quality flag; coefficient of determination; condition number; number of radial velocities; horizontal width of Doppler LIDAR data; height bounds; time bounds <strong>Technical Info: </strong> <em><strong>level1:</strong></em> dimension: 17280 x 250; temporalExtent_startDate: 2021-05-17 00:00:00; temporalExtent_endDate: 2021-07-20 00:00:00; temporalResolution: 5; temporalResolutionUnit: seconds; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; rangeResolution: 48; rangeResolutionUnit: meters; verticalResolution: 36; verticalResolutionUnit: meters; verticalStart: 0; verticalStartUnit: meters; verticalEnd: 12000; verticalEndUnit: meters; instrumentNames: Stream Line XR S/N 143 (sups_rao_dlidvad00), Stream Line XR S/N 44 (fval_tub_dlidvad00); instrumentType: Doppler LIDAR; instrumentLocation: Grenzschichtmessfeld Falkenberg, Lindenberg; instrumentProvider: Halo Photonics Ltd. <em><strong>level2:</strong></em> dimension01: 144 timesteps x 250 (10-minute mean); dimension02: 48 timesteps x 250 (30-minute mean); temporalExtent_startDate: 2021-05-17 00:00:00; temporalExtent_endDate: 2021-07-19 15:30:00; temporalResolution01: 10; temporalResolutionUnit01: minutes; temporalResolution02: 30; temporalResolutionUnit02: minutes; spatialResolution: none; spatialResolutionUnit: none; horizontalResolutionXdirection: none; horizontalResolutionXdirectionUnit: none; horizontalResolutionYdirection: none; horizontalResolutionYdirectionUnit: none; verticalResolution: 36; verticalResolutionUnit: meters; verticalStart: 0; verticalStartUnit: meters; verticalEnd: 11600; verticalEndUnit: meters; instrumentNames: Stream Line XR S/N 143 (sups_rao_dlidvad00), Stream Line XR S/N 44 (fval_tub_dlidvad00); instrumentType: Doppler LIDAR; instrumentLocation: Grenzschichtmessfeld Falkenberg, Lindenberg; instrumentProvider: Halo Photonics Ltd.. <strong>Methods:</strong> <em><strong>fval_tub_dlidvad00:</strong></em><strong><em> </em></strong>Level-1 data represent the instantaneous backscatter intensity and radial velocity profile measurements along each single ray. Level-2 data represent 10- and 30-minutes averages of the mean wind vector, respectively. All data are organized in daily files. They are based on a step-stare Velocity Azimuth Display (VAD) lidar scan pattern with 24 rays per scan circle and 30000 lidar pulses per ray at a 15 degrees zenith angle. The profiles typically cover a height range between about 90 m a.g.l. and (at least) the top of the boundary layer. The actual maximum height is highly variable, it depends on the maximum nominal range of the instrument, on the scan geometry and on the presence of scatterers in the atmosphere (e.g., aerosols, cloud particles). Besides the meteorological variables, an error estimate and a quality flag is given for each variable. Furthermore, quality test information and instrumental parameters are given. Raw data processing followed the sensitive consensus approach identifying the most reliable cluster of radial velocity retrievals along each scan direction from a series of scans during the averaging interval. Quality tests include an assessment of the coefficient of determination of the VAD fit and of the condition number indicating the sectoral coverage of the fit. The retrieval algorithm has been validated through a long-term inter-comparison of lidar-based winds versus radiosonde and radar wind profiler wind retrievals resulting in a typical uncertainty (rmsd) of 0.8 m/s and 8.0 degrees for wind speed and wind direction, respectively. Each measured value is accompanied by a quality flag where 0 = bad, and 1 = good. Note: Data from June 12 to June 23 had to be reprocessed to correct for an azimuth error, these data are labelled as version 01; all other data are labelled as version 00. <em><strong>sups_rao_dlidvad00:</strong></em> Level-1 data represent the instantaneous backscatter intensity and radial velocity profile measurements along each single ray. Level-2 data represent 10- and 30-minutes averages of the mean wind vector, respectively. They are processed by DWD using the consensus approach (see, e.g., Päschke et al. 2015 - https://doi.org/10.5194/amt-8-2251-2015) identifying the most reliable cluster of radial velocity retrievals along each scan direction from a series of scans during the averaging interval. All data are organized in daily files. They are based on a step-stare Velocity Azimuth Display (VAD) lidar scan pattern with 24 rays per scan circle and 30000 lidar pulses per ray at a 15 degrees zenith angle. The profiles typically cover a height range between about 90 m a.g.l. and (at least) the top of the boundary layer. The actual maximum height is highly variable, it depends on the maximum nominal range of the instrument, on the scan geometry and on the presence of scatterers in the atmosphere (e.g., aerosols, cloud particles). Besides the meteorological variables, an error estimate and a quality flag are given for each variable. Furthermore, quality test information and instrumental parameters are given. Quality tests of the DWD standard processing include an assessment of the coefficient of determination of the VAD fit and of the condition number indicating the sectoral coverage of the fit. The retrieval algorithm has been validated through a long-term inter-comparison of lidar-based winds versus radiosonde and radar wind profiler wind retrievals resulting in a typical uncertainty (rmsd) of 0.8 m/s and 8.0 degrees for wind speed and wind direction, respectively. Each measured value is accompanied by a quality flag where 0 = bad, and 1 = good. <strong>Units:</strong> Units for all variables (see TableOfContents): <em><strong>level1:</strong></em> <strong>sups_rao_dlidvad00</strong>: degrees; 1/ (m sr); m/s; m/s; m/s; 1; m; degrees <strong>fval_tub_dlidvad00</strong>: degrees; 1/ (m sr); m/s; m/s; 1; m; degrees <em><strong>level2: </strong></em>m/s; degrees; m/s; m/s; m/s; m/s; degrees; m/s; m/s; m/s; 1, 1, 1, 1, 1, 1, 1, m; m; s <strong>geoLocations:</strong> <em><strong>BoundingBox:</strong></em> westBoundLongitude: 14.1222 degrees East; eastBoundLongitude: 14.1287 degrees East; southBoundLatidude: 52.1665 degrees North; northBoundLatitude: 52.2098 degrees North; geoLocationPlace: Germany, UTM zone 33U <em><strong>Locations:</strong></em> Falkenberg: 52.1665 degrees North, 14.1222 degrees East, 73 meters above mean sea level Lindenberg: 52.2098 degrees North, 14.1287 degrees East, 104 meters above mean sea level <strong>Size:</strong> All data are organized in daily files. Level-1 and level-2 data of the two instruments are each packed separately into one tar archive; the total number of tar archives is hence 2 + 2 = 4. Files sizes of these archives are: Falkenberg level-1: ~1.94 GByte, level-2: 15 MByte, Lindenberg level-1: 3.75 GByte, level-2: 25 MByte; the total amount is ~ 6 GByte. <strong>Format:</strong> netCDF <strong>DataSources:</strong> Single site ground-based remote sensing, see "Technical Info" for instruments <strong>Contact:</strong> ronny.leinweber (at) dwd.de; frank.beyrich (at) dwd.de <strong>Web page:</strong> https://www.cen.uni-hamburg.de/en/icdc/data/atmosphere/samd-st-datasets/samd-st-fesstval/fval-dlidvad-wind.html see also: https://www.cen.uni-hamburg.de/en/icdc/research/samd/observational-data/short-term-observations/fesstval.html
description: Data availability: VAD profiles of the mean wind are available for the following dates at the respective sites: Falkenberg: 2021-06-12 to 2021-07-19 Lindenberg: 2021-05-17 to 2021-07-15 Funding: FESSTVaL is funded by the Deutscher Wetterdienst within the Hans-Ertel Centre for Weather Research.