@article{oai:nipr.repo.nii.ac.jp:00004060,
 author = {Nagano, Hiroshi and Araki, Tohru and Iyemori, Toshihiko and Sato, Natsuo and Ayukawa, Masaru},
 journal = {Proceedings of the NIPR Symposium on Upper Atmosphere Physics},
 month = {Nov},
 note = {P(論文), In order to clarify the characteristics of cosmic radio noise absorption (CNA) associated with geomagnetic sudden commencements (SC's), 142 SC events were analyzed with 1-second data observed at Syowa Station from April 1981 to December 1986. Local time dependence can be seen in the SC occurrence rate and average intensity of CNA increase. The occurrence rate is highest near midday and shows a secondary small peak near midnight. The average intensity is strong in the daytime and also near midnight. A strong absorption occurs at the time of large SC's with high pre-SC AE index. The intensity of CNA increase tends to be stronger as the rise time of CNA is shorter. Furthermore, it tends to be stronger when the absolute value of the ratio of vertical component to horizontal component for magnetic SC preliminary impulse at Syowa Station is smaller.},
 pages = {15--24},
 title = {Characteristics of CNA associated with geomagnetic sudden commencements},
 volume = {2},
 year = {1989}
}