Cloud-to-Ionosphere Discharge, Electromagnetic Radiation and Their Effect on Power Transmission.

众所周知，日本海域冬季闪电具有显著的云对地正放电（+CG）特征，对北陆地区的输电影响极为严重。这样的+CG最近被发现在大气中触发一个强电场，诱导红精灵（或左右）并导致电离层下层的扰动。这项工作将集中于全面了解这种高层大气放电和相关现象，以及这种放电对电力传输的影响。在1997/1998年冬季，我们对北陆冬季闪电及其相关现象进行了第一次实验；(1)北海道Moshiri地区高层大气排放的极低频瞬变观测，(3)低电离层扰动的VLF散射（利用NWC亚电离层信号传播）。在第一个冬天，由于准备不充分，光学测量不是很好，但我们可以列出其他现象的重要特征。当我们比较+GG和-CG的相关现象（极低频谱线和极低频散射）时，发现+CG比-CG更频繁地触发极低频瞬变和电离层扰动（约两倍）。然而，当我们假设电离层下方存在等离子体柱时，这种差异就不那么大了，这意味着这种等离子体柱的假设是值得怀疑的。在1998/1999年的第二个冬天，我们再次成功地进行了测量，现在我们正在广泛地分析数据。我们希望我们能取得显著的成果，特别是非常重视光学测量。最后，研究了这种放电对输电（或输电线路）的耦合。然后，利用传输线模型得到了在传输线末端感应的电压和电流。少

It is well known that winter lightning in the Japan sea area has a significant characteristic of positive cloud-to-ground discharge (+CG), and that it has an extremely serious influence on the power transmission in the area of Hokuriku. Such +CG is recently found to trigger a strong electric field in the atmosphere, inducing red sprites (or so) and leading to the perturbation in the lower ionosphere. This work will focus on the complete understanding of this upper atmosphere discharges and the associated phenomena, and also on the effect of such discharges on the power transmission.During the winter of 1997/1998, we tried the first experiment for the Hokuriku winter lightning and the associated phenomena ; (1) optical measurement from Mt. Zao in Tahara town near Toyohashi, (2) observation of ELF transients from the upper atmosphere discharges at Moshiri in Hokkaido, and (3) VLF scattering from the lower ionospheric perturbations (by means of the NWC subionospheric signal propagation). … More In the first winter the optical measurement was not so good due to the insufficient preparation, but we can list the important features for other phenomena. When we compare the associated phenomena (ELF sferics and VLF scattering) for +GG and -CG, it is found that +CG could trigger ELF transients and ionospheric perturbation more often (by about twice) than for -CG.However, this difference is not so big when we assume the presence of plasma column below the lower ionosphere, which means that this kind of hypothesis of such a plasma column is questionable.During the next winter of 1998/1999, we made the successful measurement again, and we are now analyzing the data extensively. We do hope that we could obtain significant results, especially with great emphasis on the optical measurement.Finally, the coupling of such discharges on the power transmission (or transmission lines) was investigated. Then, we have obtained the voltage and current induced at the end of the transmission line by means of the transmission line model. Less