Calculation of electromagnetic fields from incloud discharges at close range
Bipolar pulses were a type of incloud lightning discharge phenomenon whose physical mechanism remains unresolved. In this report a program was developed to simulate the close electromagnetic fields of this phenomenon. The incloud discharge was taken as a current pulse running through a short channel inside cloud at a speed comparable to the speed of light. The simulated results show that electromagnetic field characteristics depend on distance. At very close range the electric field was dominated by the inductive and electrostatic fields and appeared as the asymmetrical V-shaped pulse,or asymmetrical V-shaped pulse with a leading sharp pulse at the beginning, while at distance of 6-8km or more the electric field was dominated by radiation field and was basically bipolar in shape. On the contrary the magnetic field was always dominated by radiation field component and was bipolar in shape. Simulated results were consistent with characteristics of observed close electromagnetic fields from preliminary breakdown preceding the negative cloud-to-ground flashes.
Zhu Baoyou Zhou Helin Tao Shanchang
School of Earth and Space Sciences,University of Science and Technology of China,Hefei,230026,China
国际会议
第13届国际大气电学会议(The 13th International Conference on Atmospheric Electricity)
北京
英文
2007-08-13（万方平台首次上网日期，不代表论文的发表时间）