Observational study of veering wind by Doppler wind profiler and surface weather station

The information on the variation of mean wind speed with height is useful or required in various branches of engineering practices. However, the dependence of varying wind direction on height has often been disregarded in wind engineering. This study aims to further the understanding of the dependence on height of varying wind direction based on long-term wind measurements from Doppler wind profiler and a surface weather station in Hong Kong. The veering angle profiles are obtained by means of composite analysis, and their characteristics are examined as a function of topographic condition, wind speed and storm type (i.e. monsoons and typhoons), respectively. The results suggest that, the veering angle profiles have a strong dependence on the change of upwind topographic condition, which leads to noticeable divergences in terms of the shape of veering angle profiles, the peak value of veering angle and the slope of the profiles. Second, the correlation of the veering angle profiles with wind speed is estimated under near-neutral stable condition. No clear correlation is identified between the veering angle profiles and wind speed. Furthermore, the phenomena of veering wind under monsoon and typhoon conditions are assessed, in which there are excellent agreements in respect to the veering angle profiles under 800 m. Nevertheless, significant deviations arises at higher elevations.