资源环境科技发展态势分析平台

An abnormal discharge process after a return stroke (RS) in a negative cloud-to-ground flash was studied in detail. Correlating high-speed video images and electric field data, it was found that the abnormal discharge process was initiated at ground and transported positive charge from ground toward cloud. Moreover, there was a long continuing current (CC) initiated by the abnormal upward discharge process. Compared with the characteristics of RSs, CCs and M components, we conclude that the upward discharge process is a kind of upward positive leader. The 3-D speeds of the positive leader range from 3.72x10(6)m/s to 14.48x10(6)m/s with average value of 6.5x10(6)m/s. As far as we know, it is the first report that a long CC follows the upward positive leader after RS, which is obviously different from traditional CCs. The discovery is helpful to gain a deeper understanding of the mechanism and physical process of negative cloud-to-ground flashes.

Plain Language Summary There is an abnormal upward discharge process that occurred after the fourth return stroke. Moreover, a long continuing current following the abnormal upward discharge process could be found. As far as we know, it is the first report on this phenomenon.