BROADBAND INTERFEROMETER OBSERVATIONS OF THE BI-DIRECTIONAL BREAKDOWN PROCESS IN NATURAL LIGHTNING
用宽带干涉仪观测云内闪电通道双向传输的特征

The bi-directional propagations of a lightning channel within clouds have been observed for both the cloud-to-ground and cloud discharges by use of a lightning broadband interferometer system. After a lightning discharge is initiated within the negative charge region of clouds, its channel development shows bi-directional propagations with two concurrent breakdown processes extending in opposite directions from the extremities of the lightning channel. Radiation field spectra of the two concurrent breakdown processes are quite similar, indicating that the processes may be negative breakdown and may be caused by the same mechanisms. During the bi-directional propagations of the channel, the electric field change indicates that the negative charge moves upward along the channel. These results are dissimilar to the concept of bi-directional, uncharged leader previously proposed by Kasemir.