@article{oai:nipr.repo.nii.ac.jp:00004267,
 author = {Kitamura,Kentarou and Yumoto,Kiyohumi and the 210°MM Magnetic Observation Group},
 journal = {Proceedings of the NIPR Symposium on Upper Atmosphere Physics},
 month = {Dec},
 note = {P(論文), Magnetic field data from two pairs of conjugate stations along the 210°MM (Magnetic Meridian) are analyzed to re-examine characteristics of northern/southern hemisphere asymmetry of sc (sudden commencement)/si (sudden impulse) magnetic variations. We found that the seasonal variation of the asymmetry of sc/si can be seen even in the nighttime sector, where the ionospheric conductivity is much lower than that in the daytime sector. In order to interpret the observational fact, we have estimated the magnetic fields in the magnetosphere produced by the Chapman-Ferraro current (CF current) flowing at the dayside magnetopause, by using the Tsyganenko 96 model. It is found that the observed northern/southern hemisphere asymmetry of sc/si in the nighttime sector can be explained by invoking the seasonal variation in the tilt angle of Earth's dipole axis.},
 pages = {108--114},
 title = {Northern/southern hemisphere asymmetry of sc/si in the nighttime sector},
 volume = {12},
 year = {1998}
}