@article{oai:nipr.repo.nii.ac.jp:00006340, author = {Yokoyama,N. and Goka,T. and Matsumoto,H. and Koga,K. and Koshiishi, H. and Kimoto, Y.}, journal = {Advances in polar upper atmosphere research}, month = {Sep}, note = {P(論文), In this study we have examined the relationship between the energetic electron flux at geostationary orbit and the solar wind speed. We have compared the electron flux ( >0.4MeV) observed by the Engineering Test Satellite V (ETS-V) with solar wind speed measurements in the OMNI data set obtained from the National Space Science Data Center (NSSDC). The tendency has been observed for the logarithm of the electron flux to be proportional to the solar wind speed at solar minimum, but scattered at solar maximum. We have found that during the main and recovery phases of magnetic storms occurring at solar minimum, the logarithm of the electron flux is roughly proportional to the solar wind speed. At solar maximum, however, there is no apparent correlation between both these parameters. Moreover, in quiet periods there is also no observable correlation at both solar minimum and maximum. The dependence of the electron flux at geostationary orbit on the solar wind speed is related to recurrent storms caused by high-speed solar wind streams.}, pages = {193--200}, title = {Solar wind dependence of the electron flux variation at geostationary orbit observed by ETS-V}, volume = {15}, year = {2001} }