利用雨滴谱检验毫米波雷达速度数据方法研究

Inspection of the velocity observation with the cloud radar by disdrometer

中国气象局气象科学研究院灾害天气国家重点实验室的毫米波雷达未对其观测的弱降水数据进行定量对比研究,为此通过分析2013年在广东三水使用毫米波雷达观测的速度数据,确定该雷达观测速度数据的可靠性。在研究了雷达在一定有效高度上的观测量和地面雨滴谱计算量的联系和差别基础上,提出了利用雨滴谱反演雷达观测径向速度和速度谱宽,来对比毫米波雷达在一定有效观测高度处探测降水粒子速度数据的方法,分析毫米波雷达观测速度数据差异的来源,并且对速度数据进行分析,确定速度数据的质量。结果表明:径向速度受空气的上升速度影响使得两者数值有一定差异,但变化趋势却十分接近,由空气上升速度导致的平均差别为0.89 m·s-1;速度谱宽两者演变趋势和变化范围均非常接近,速度谱宽平均差别为0.15 m·s-1。

Since a quantitative study of the cloud radar, which belongs to State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences for measuring light precipitation has not been carried out so far, in this paper the radar observation data at Sanshui in Guangdong in 2013 are analyzed to determine the radar reliability and error. Examining the connection and difference between the cloud radar observation in a certain height and the calculation using disdrometer data on the ground, a methods is proposed to compare the velocity and spectral width calculated from raindrop size distribution with those observed by the cloud radar observation in a certain height for light precipitation. The source of the radar observation errors can be analyzed, and the quality of the data can be determined. The results showed that the radial velocity values which are affected by updraft have notable difference between those observed and calculated although both change roughly with a similar trend over time. The average error caused by updraft is 0.89 m·s-1. The spectral width from cloud radar and disdrometer data were corresponded well; its average error is 0.15 m·s-1.