Mailbox 5111 Beijing 100094 China;
National Space Science center Chinese Academy of Sciences Beijing 100190 China;
Mailbox 5111 Beijing 100094 China;
Mailbox 5111 Beijing 100094 China;
Mailbox 5111 Beijing 100094 China;
Mailbox 5111 Beijing 100094 China;
geomagnetic storms; substorms; normalized superposed epoch analysis; initial phase; IMF Bz;