Characterization of Positive Cloud to Ground Flashes Observed in Indonesia

• Main Authors: Ariadi Hazmi, Primas Emeraldi, Muhammad Imran Hamid, Nobuyuki Takagi, Daohong Wang
• Format: Article
• Language: English
• Published: MDPI AG 2017-01-01
• Series: Atmosphere
• Subjects: positive lightning; return stroke; interstroke interval; multiple ground termination
• Online Access: http://www.mdpi.com/2073-4433/8/1/4

The characteristics of 77 electric field changes of positive cloud to ground (CG) flashes in the tropics of Indonesia were investigated. It was found that the arithmetic mean (AM) and geometric mean (GM) values for 0%–100% and 10%–90% rise time were 12.7 μs, 11.9 μs and 6.1 μs, 5.8 μs, respectively. The percentages of single, double, and triple strokes of lightning flashes were 83% (64 cases), 16% (12 cases), and 1% (1 case), respectively. The AM and GM of the interstroke intervals and the return stroke (RS) amplitude ratios were 163.9 ms, 0.29, and 13.3 ms, 0.26, respectively. Furthermore, it was also found that 7 (9%) of 77 positive CG flashes had double peak return stroke waveforms with AM and GM values for 0%–100% and 10%–90% rise time of subsequent return strokes that were 6.7 μs, 6.4 μs and 4.1 μs, 4 μs, respectively. We inferred that these double peaks are produced by two ground terminations with a time interval varying from 7 to 560 μs.