@article{oai:nipr.repo.nii.ac.jp:00006304,
 author = {Hosokawa, Keisuke and Iyemori, Toshihiko and Yukimatu, Akira Sessai and Sato, Natsuo},
 journal = {Advances in polar upper atmosphere research},
 month = {Aug},
 note = {P(論文), Sudden perturbations of the ground magnetic fields at solar flares are called geomagnetic Solar Flare Effect (SFE). An SFE is the extra ionization produced by the X-ray emission from a solar flare. We analyzed 10 intense SFE events from 1996 to 1998 using SuperDARN HF radar network and other instruments located in the northern hemisphere. Two typical ionospheric signatures associated with the solar flares are revealed, one is a sudden fade-out of backscatter echoes, and the other is an appearance or variation of field-aligned irregularities. Sudden fade-out is observed only in the sunlit hemisphere, and the appearance or variation of irregularities are observed only near the terminator. In addition, we investigated one event out of ten in detail and found that there exists a discontinuity of the electric field or conductivity around the irregularity. This fact suggests that the variation of conductivity or electric field in the E region could affect the irregularity formation in the F region.},
 pages = {66--75},
 title = {Characteristics of solar flare effect in the high-latitude ionosphere as observed by the SuperDARN radars},
 volume = {14},
 year = {2000}
}