多普勒雷达实时反射率因子垂直廓线观测研究

使用2002年6～7月长江中游地区宜昌S波段多普勒雷达在两次大范围混合性强降水过程中部分时段体积扫描强度数据以及周边100km范围内的7个雨量计整理成10min记录一次的雨量资料，分析了实时雷达反射率因子垂直廓线的特征。研究表明：反射率因子垂直廓线可反映出所选区域上空零度层亮带高度位置、回波的垂直变化规律等信息，以此分析降水的类型、云中粒子的发展变化；从雷达连续体扫得到的中、低仰角对应高度上的实时反射率因子垂直廓线的变化规律、PPI图像上对应雨量站点上空的回波变化情况及10min记录一次的地面雨量的变化趋势对比来看，发现三者能很好地统一起来，可用来较细致地分析降水云体的变化，有利于在无地面雨量计的地区分析降水量的大小、确定降水类型、估测降水的发展；对无亮带、反射率因子值较大而且越低仰角值越大的反射率因子垂直廓线的区域，对应地面上常有对流性强降水出现。

Observational Study on the Real-Time Vertical Profile of Reflectivity by the Yichang's Doppler Radar in Summer

Based on the volume scan data from the Doppler radar deployed in Yichang, and nearly simultaneous 10-minutes precipitation from 7 gauges distributed within 100 km centered radar's position, The real time characteristics of vertical profile of radar reflectivity (VPR) during the two time periods of regional intensive mixing precipitation in June and July in 2002 are analyzed. The VPRs clearly show the vertical structures of bright band of zero-temperature layer over the selected area, together with the vertical variations of the echoes, types of the precipitations, and physical status of the particles in the precipitation-cloud etc. The information from VPRs could be applied to analyze the types of the precipitation, and the evolution of particles in the cloud. There are agreements among the variations of VPRs detected at middle or low elevation angles in the continuous volume scans, echoes of PPI images exactly located over the gauge sites, and the 10-minutes amount of precipitation recorded by gauges, and these agreements are useful to estimate the amounts, types, and the evolutions of precipitation over the sites where the gauges are absent. Intensive convective precipitation usually occurred over the regions that VPRs detected together with no bright band, the big reflectivity factors, and the bigger reflectivity factors, the lower elevation angles.