K-type breakdown process of intracloud discharge in Chinese inland plateau

Some special features of lightning discharges in the eastern area of Qingha i-Tibetan Plateau have been investigated through multi-station measurements of wide-band slow antenna systems synchronized by Global Positioning Syste m (GPS) with a time resolution of 1 mu s The K-type breakdown processes dur ing one intracloud (IC) discharge were analyzed using the time differences of radiation pulses arriving at different stations. It was found that K-typ e breakdown processes during IC discharge started from a negative charge re gion and propagated downward to the lower positive charge region with an av erage speed of 1.5 x 10(7) m/s. The altitude of negative charge region was between 5.0 and 6.0 km above ground, while that of positive charge region w as between 2.5 and 3.5 km above ground.