华南前汛期暴雨C波段雷达特征应用研究

运用广州白云机场C波段雷达回波强度及径向风资料对华南前汛期强降水过程进行雨带降水估计及其移动特征预测.C波段雷达在雨量充沛地区的强降水背景下，尽管回波强度被衰减，但是近距离范围内其探测云雨精细化结构的能力较强.所采取的雷达数据质量控制系列处理，能够保留雷达数据原有特征，有效滤去杂波和噪声并缓解雷达低仰角数据杂波多、体扫面上沿径向远近高度差较大的问题，并对降水估测提供了技术保障.最优化雷达Z-I强降水估测方法基于单次过程体扫信息，具有计算简洁快速的特点，但是同一体扫面上云状差异对最优化方法参数值比较敏感，混用相同参数，影响降水估测效果.对同一体扫面上雷达云状回波进行区域划分，并选择对应测雨站点，做最优化参数分别确定，有效改善最优化雷达降水估测，提高了C波段雷达在机场近距离范围的应用效果.运用雷达体扫时间分辨率高的特点，识别雷达径向风辐合线以及强回波中心位置，并分别应用外推法预测雨带走向、移速等，验证效果良好.

Characteristics of C-band weather radar and application on heavy rainfall estimation in the first flood season of South China

Based on the C-band radar echo intensity and radial wind data of Guangzhou Baiyun Airport, the precipitation amount estimation and the rain belt moving prediction are carried out for the heavy precipitation process in South China during the first flood season. In the strong precipitation background of abundant rainfall areas, the C-band radar has better ability to detect cloud rain refinement structures, although the echo intensity is attenuated. The radar data quality control processing can preserve the original characteristics of the radar data, effectively filter out clutter and noise, and alleviate the problem that the radar data has many clutter at low elevation angle scanning surface and the altitude difference along radial direction. The data processing provides a technique support for precipitation estimation. The optimized radar Z-I precipitation estimation method is only based on information of each scanning procedure, so its calculation is simple and fast. However, the cloud type difference on the same scanning surface is sensitive to the parameter values of the optimization method, when the same parameters are used in different clouds that will affect the estimation effect of precipitation. By separating areas of the radar cloud echoes on the same scanning surface and selecting rainfall stations, the optimization parameters can be determined according to different cloud echoes, which can improve the optimal radar precipitation estimation. According to the short characteristics of radar scanning time, the radar radial wind convergence line and the strong echo center position are identified, and the extrapolation method is used to predict the rain belt orientation, position and moving speed. The verification effect is good.