关键词: 北京城市, 复杂下垫面, 边界层测风, 资料对比

Abstract:

Based on the synchronous observation data of laser wind radar (Lidar), wind profile radar (WPR) and GPS radiosonde (GPS) in boundary layer in Chaoyang District of Beijing from 28 August to 2 September 2016, the performance of three kind of instruments on measuring wind speed and wind direction under complex underlying surface conditions were compared and analyzed. The results are as follows: (1) The vertical profiles of wind speed and wind direction detected by Lidar were quite consistent with GPS in boundary layer in Chaoyang District of Beijing from 28 August to 2 September 2016, and the correlation coefficients of wind speed and wind direction ranged from 0.66 to 0.96 and 0.71 to 0.98, respectively. The average absolute error of wind speed was less than 2 m·s-1, and for wind direction it was less than 20°. (2) The accuracy of WPR data was relatively poor, the correlation coefficients of wind speed and wind direction between WPR and GPS ranged from 0.66 to 0.91 and 0.55 to 0.86, respectively, and the errors decreased first and then increased with the increase of height. The consistency of two data from 400 m to 1000 m height was higher, the correlation coefficients were greater than 0.80, the detection of  range from 400 m to 1000 m was best. Moreover, the values of wind speed detected by WPR were usually larger than that of GPS, the maximum deviation was about 4 m·s-1, and the maximum error of wind direction was up to 30°. (3) GPS also had shortcomings. The frequency of observation was relatively low, and it was difficult to describe the change process of wind field in boundary layer in detail. There was a significant lag error at the beginning of GPS detection under the vertical wind shear condition. That is, the air balloon takes a certain time to transform from initial state to true wind field tracer.

Key words: Beijing, complex underlying surface, wind measurement in boundary layer, data comparison