Response of Nightside Aurora to Interplanetary Shock from Ground Optical Observation

AbstractInteraction between interplanetary shock and magnetosphere frequently induces dayside enhancements of auroral activity, and subsequent enhancement of auroral precipitation referred as shock aurora propagating dawnward and duskward from noon to the night sector. In some cases, these interplanetary shocks also induce enhanced activity during which the power precipitated into the night sector may reach values as high as observed during typical magnetospheric substorms. Present study analyzes the nightside auroral responses to the interplanetary shock sudden compression based‐on the ground optical auroral observations from Chinese Antarctic Zhongshan (ZHS) and Arctic Yellow River (YRS) stations for the first time. The analysis result of 18 shock associated aurora cases indicated that nightside auroral responses can be classified into auroral breakup and weak intensification or quiescent events. Epoch time analysis showed that both the solar wind‐magnetosphere coupling efficiency and electro‐magnetic environment inside magnetosphere determine the nightside auroral responses.