风廓线雷达探测降水过程的初步研究

为利用风廓线雷达 (WPR) 开展降水研究, 分析了2006年8月25-26日北京延庆WPR探测降水个例。降水前高空出现持续时间长达10h以上的水平风垂直切变; 在信噪比 (SNR) 时间序列资料中出现比较清晰的SNR极值层, SNR极值层所处高度与水平风垂直切变高度相吻合。降水期间及前后, 水平风探测高度明显增高2km以上。随地面降水的临近, 下降速度所处高度逐渐降低, 从高空一直延伸到低空, 持续时间长达10h。资料分析表明:国产WPR可以在降水天气工作, 其探测资料能及时反映大尺度流场的变化。通过WPR提供的功率谱密度、SNR、水平速度、垂直速度等多种资料, 可从多种角度了解降水过程; 特别是WPR可以同时探测垂直气流速度、粒子落速及其高度分布, 进而可以估计降水粒子尺度谱及其高度分布, 便于开展更深层次的降水物理过程研究。

Preliminary Study on Precipitation Process Detection Using Wind Profiler Radar

In order to investigate precipitation process using wind profiler radar (WPR), an observation case is analyzed. WPR is very sensitive to precipitation process and can be used to detect many indicative phenomena before the rain. In this case, horizontal wind shear is recognized 10 hours before the precipitation, and the maximum observation-height increases by at least 2 km than usual. As the rainfall draws near, the height of downward speed gradually decreases.Data analysis shows that domestic WPR is applicable to work in precipitation weather. It provides various instructive data for studying precipitation such as horizontal wind, vertical wind and signal to noise ratio data. Further, WPR can provide data of wind speed, falling speed of rain-drops and their vertical distribution simultaneously, so it' s fairly useful for investigating precipitation process in depth.