The Study on a Solar Storm and Its Interplanetary and Geomagnetic Effects

We present a detailed study on a solar storm occurred on 2014 January 7. By using the remote-sensing observations of solar activities at multiple wavelengths from the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO), the eruptions of the solar flare and coronal mass ejection (CME) are investigated. Based on the measurement of energetic protons from the Geostationary Operational Environmental Satellite (GOES) and the in-situ plasma measurement from the Advanced Composition Explorer (ACE) at the solar-terrestrial L1 point, the solar energetic particle (SEP) event and interplanetary CME (ICME) accompanied by the solar storm, and the shock driven by the ICME are analyzed. The influence of the solar storm on the geomagnetic fields is also analyzed with the ground-based magnetic data. The results in this study show that: (1) The initial time of impulsive phase of the solar flare and the ejection time of the CME are temporally in accordance with each other. (2) The solar protons are mainly accelerated by the CME-driven shock, rather than by the magnetic reconnection in the flare, and the protons are released when the CME travels to 7.7 solar radius. (3) The widths of the interplanetary shock sheath and the ICME itself are derived to be 0.22 AU and 0.26 AU, respectively. (4) The interplanetary shock and the ICME give rise to substorms and aurora, whereas no obvious geomagnetic storm is detected. The reason is that the ICME does not contain a regular structure of magnetic cloud (MC) or evident southward component of magnetic field.