The electrical structure of the hokuriku winter thunderstorms

摘要: Lightning charges, locations, and currents have been determined for 12 flashes from four winter storms observed on the Hokuriku coast of Japan during December 1977 through January 1978. Additional data is available a total eight storms. The heights magnitudes charges in strokes-to-ground were calculated simultaneous measurements electric field changes made at seven stations covering an area about 150 km2. Discharges lowering positive charge to earth often exhibit large continuing (>104 A) periods up 10 ms. One discharge involved peak current value ≃105 A that exceeded 300°C after 4 Negative strokes are generally order magnitude smaller, ≃4×103 A, involving 100°C or less. lightning located higher than negative same storm, constituting ‘normal’ bipolar system similar configuration found summer thunderstorms. For this study, 26 out 63 positive. strong correlation exists between fraction ground vertical wind shear cloud layer. On basis study we suggest occurrence consequence shear. provides horizontal displacement helps ensure initiating streamer will continue down rather into negatively charged region would normally be directly below it. should appear threshold layer 1.5 m/s/km.