Flow observations using nacelle lidars: A study on the University of Stavanger campus

Abstract This study deals with wind measurements on the campus of the University of Stavanger, using two continuous-wave nacelle lidars and a vertical continuous-wave profiler. Wind data is further acquired by 2-D sonic anemometers fixed to the lidars. The emphasis of the analysis is on the data gathered by the nacelle lidars. The horizontal wind speeds reconstructed from the radial velocities are compared to the recordings of the sonic anemometers and analysed in terms of mean wind profiles over the extent of the scanning circle. Standard logarithmic and power laws are fitted to the profiles to estimate site-specific parameters such as wind shear exponent and surface roughness. Turbulence characteristics in the mean wind direction, such as spectra and variances, are estimated and compared to those from the sonic anemometer. The study demonstrates the overall potential of remote sensing for wind monitoring in an urban environment. The wind velocities acquired in the individual measurement points along the nacelle lidars’ scanning circles are found to capture the flow in the monitored regions around the buildings in a realistic way. Together with the information from the vertically pointing wind profiler, the measurement data represents a valuable source for validation of related numerical models for flow in an urban area.