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

摘要：

利用2016年8月28日至9月2日北京市朝阳区气象观测站激光测风雷达、风廓线雷达和GPS探空仪同步观测数据，对比分析三种测风仪在城市复杂下垫面条件下边界层不同高度处的测风性能。结果表明：（1）激光测风雷达与GPS探空仪测风结果具有较好一致性，风速、风向的相关系数分别为0.66~0.96、0.71~0.98，其中风速平均绝对误差小于2 m·s-1，风向误差在20°之内。（2）风廓线雷达资料的精度相对较差，与GPS探空仪的风速、风向相关系数分别为0.66~0.91、0.55~0.86，误差随高度呈现先减后增的垂直分布特征。其中，400~1000 m高度范围两种资料的吻合度最高，相关系数在0.80以上，为仪器最佳测量范围；此外，风廓线雷达的风速整体高于GPS探空仪，两者最大偏差可达4 m·s-1左右，风向平均误差最大可达30°。（3）GPS探空仪的工作方式及测量结果也存在不足，一是观测频次较低，难以详细、精准地描述边界层风场结构的变化过程；二是当存在垂直风切变时，探测初期具有明显滞后性，由当前状态转变为真实的风场示踪物需要一定时间。

关键词: 北京城市, 复杂下垫面, 边界层测风, 资料对比