基于X波段双偏振相控阵雷达的超级单体风暴观测分析

为了研究X波段双偏振相控阵雷达对超级单体风暴的探测能力，利用X波段双偏振相控阵雷达和S波段双偏振天气雷达资料，分析了一次发生在华南地区的超级单体风暴在成熟阶段的精细结构观测特征，结果表明：X波段双偏振相控阵雷达较高的时空分辨率有利于精细监测超级单体快速演变过程，但同时受衰减影响明显，超级单体核心区后侧出现明显的“V”型缺口；超级单体的低层观测到CC谷和ZDR弧，中层观测到ZDR环和CC环，高层高ZH区对应较小的ZDR和CC，这些都是超级单体发展旺盛的重要特征；垂直方向上观测到ZDR柱，ZDR柱与上升气流密切相关。降雹前ZDR柱迅速增加，冰雹降落后ZDR柱高度迅速降低。冰雹降落到地面后会部分融化，导致含水量显著增加，因此在近地层出现KDP大值区，冰雹与降水的混合相态则使得CC降低，这对冰雹的临近预警和识别冰雹在地面的降落位置具有很好的指示意义。研究结果可为X波段双偏振相控阵雷达在强对流天气监测预警中的应用提供参考。

X-BAND DUAL-POLARIZATION PHASED-ARRAY RADAR OBSERVATIONS OF A SUPERCELL

To investigate the capability of X-band dual-polarization phased-array radar to detect supercells, we analyzed the fine-structure characteristics of a supercell storm during its mature stage in south China by using data from X-band dual-polarization phased-array radar and S-band dual-polarization weather radar. The results show that the high temporal and spatial resolution of X-band dual-polarization phased-array radar can facilitate the fine monitoring of the rapid evolution of supercells; however, at the same time, it is significantly affected by attenuation, and there is an obvious V-shaped gap at the back of the core area of the supercell. ZDR columns are observed in the vertical direction, and this is closely related to updrafts. ZDR columns develop rapidly before it hails, and the height of ZDR columns decreases rapidly after it hails. After the hail falls to the ground, it will partially melt, resulting in a significant increase in water content, so there is a large KDP value area in the near-surface layer. Moreover, the mixed phase of hail and precipitation reduces the CC, which appears to be a good indication for the early warning of hail weather and the identification of the landing position of hail on the ground. The research results can provide reference for the application of X-band dual-polarization phased-array radar in severe convective weather monitoring and early warning.