Cheynet, E.Jakobsen, J.B.Snæbjörnsson, J.Mann, J.Courtney, M.Lea, G.Svardal, B.2025-11-172025-11-172017-09-21Cheynet, E, Jakobsen, J B, Snæbjörnsson, J, Mann, J, Courtney, M, Lea, G & Svardal, B 2017, 'Measurements of surface-layer turbulence in awide norwegian fjord using synchronized long-range doppler wind lidars', Remote Sensing, vol. 9, no. 10. https://doi.org/10.3390/rs91009772072-4292143495667fdd3cea6-6a96-4040-99d2-4e88943035ffORCID: /0000-0003-4391-9925/work/8113204485032871861researchoutputwizard: hdl.handle.net/20.500.11815/1622Core: 289151801https://hdl.handle.net/20.500.11815/6032Three synchronized pulsed Doppler wind lidars were deployed from May 2016 to June 2016 on the shores of a wide Norwegian fjord called Bjornafjord to study the wind characteristics at the proposed location of a planned bridge. The purpose was to investigate the potential of using lidars to gather information on turbulence characteristics in the middle of a wide fjord. The study includes the analysis of the single-point and two-point statistics of wind turbulence, which are of major interest to estimate dynamic wind loads on structures. The horizontal wind components were measured by the intersecting scanning beams, along a line located 25m above the sea surface, at scanning distances up to 4.6km. For a mean wind velocity above 8m.s(-1), the recorded turbulence intensity was below 0.06 on average. Even though the along-beam spatial averaging leads to an underestimated turbulence intensity, such a value indicates a roughness length much lower than provided in the European standard EN 1991-1-4:2005. The normalized spectrum of the along-wind component was compared to the one provided by the Norwegian Petroleum Industry Standard and the Norwegian Handbook for bridge design N400. A good overall agreement was observed for wave-numbers below 0.02m(-1). The along-beam spatial averaging in the adopted set-up prevented a more detailed comparison at larger wave-numbers, which challenges the study of wind turbulence at scanning distances of several kilometres. The results presented illustrate the need to complement lidar data with point-measurement to reduce the uncertainties linked to the atmospheric stability and the spatial averaging of the lidar probe volume. The measured lateral coherence was associated with a decay coefficient larger than expected for the along-wind component, with a value around 21 for a mean wind velocity bounded between 10m.s(-1) and 14m.s(-1), which may be related to a stable atmospheric stratification.977887827info:eu-repo/semantics/openAccessWind coherenceTurbulence spectrumPulsed lidarFull-scale measurementsWindScanner systemBridgesVindmælingarVindálagVatnsborðBrýrByggingarverkfræðiNorwayNoregurWind coherenceTurbulence spectrumPulsed lidarFull-scale measurementsWindScanner systemBridgesVindmælingarVindálagVatnsborðBrýrByggingarverkfræðiNorwayNoregur/dk/atira/pure/researchoutput/researchoutputtypes/contributiontojournal/article10.3390/rs9100977