降水过程中多普勒天气雷达风廓线产品特征

利用南京多普勒天气雷达资料,在对VWP风廓线产品可靠性研究和表征"湿度"变化能力研究基础上,对南京地区春季大面积积层混合云降水过程中风廓线产品的特征进行了细致研究.研究表明,在降水前夕、维持增强和降水消亡的不同时段风廓线产品都呈现出相应的图像特征:在图像上ND区域呈现一楔形,快速减少,预示着降水在2个小时内发生;暖平流、切变层和大风区的存在有利于降水的维持和加强;VWP最高位置风向标的突降和中层ND区域的出现预示着降水即将结束.

Analysis on Characteristics of VWP Wind Product of Doppler Weather Radar During Rainfall Process

Based on the study of VWP product reliability and its capability representing at mospheric humidity, the characteristics of VWP product in spring large scale rai nfall process in Nanjing are statistically analyzed and studied in detail by usi ng Doppler weather radar data of Nanjing. The results show that VWP product pres ents respective characteristics at different stages of rainfall development (for mation, development and dissipation). The main points are as follows: ND area in VWP images presents a wedge shape and is decreasing quickly, which indicates th e appearance of rainfall within 2 hours; the existence of warm advection, shear layer and strong wind area are propitious to the continuance and reinforcement o f the precipitation; an abrupt reduceof the highest vane in the VWP production or the emergence of ND area in the mi ddle layer predicts that the rainfall will end soon.