@article{oai:nipr.repo.nii.ac.jp:00006366,
 author = {Otsuyama, Takuya and Kariya, Tadao and Hayakawa, Masashi},
 journal = {Advances in polar upper atmosphere research},
 month = {Sep},
 note = {P(論文), The VLF signature of ionospheric perturbations associated with winter lightning in the Hokuriku area (Japan) were investigated over a 3-month period (December 2000 to February 2001). During this observation period, no optical phenomena were observerd; thus, the presently reported observation period was not so active as the observatian period for the previous winter (Y. Hobara et al. ; Geophys. Res. Lett., 28, 935, 2001). Based on the VLF subionospheric observations of the NWC (Australia) signal obtained at Moshiri (Hokkaido) and Kasugai (near Nagoya), we obtained the following results: (1) Trimpis tend to occur when lightning activity is enhanced, (2) Trimpis are observed when the causative lightning is very close to the great circle path, and (3) the amplitude of the scattered signal is in the range of -12dB to -28dB (with respect to the unperturbed signal), independent of the polarity. These characteristics lead us to conclude that the Trimpis in our observations are due to the electromagnetic pulse of lightning discharges occurring close to the great circle path and with sufficient charge transfer.},
 pages = {109--119},
 title = {VLF signatures of ionospheric perturbations associated with winter lightning in the Hokuriku area of Japan},
 volume = {17},
 year = {2003}
}