A Stastistical study of plasmas density oscillation induced from pc1 wave by Swarm Satellites during storm time from 2014 to 2018

     

        The high-resolution Vector Field Magnetometer and Langmuir Probe onboard the Swarm satellites provide us an opportunity to observe both EMIC wave and plasma density oscillation. A total of 102 plasma density oscillation events were found during storm time from 2014 to 2018. The temporal and spatial distribution of these oscillation events is roughly consistent with the EMIC wave. The longitudinal distribution and related mechanism are studied. There are obvious magnetic local time (MLT) differences in the peak occurrence rate of plasma density oscillation during storm phases and distinct geomagnetic activity. As the geomagnetic disturbance intensifies，the plasma density oscillations show a trend of westward drift and are more likely to occur at lower latitudes. For all plasma density oscillation events, the phase of these oscillation with EMIC wave is different. Most plasma density oscillation have a relative amplitude ratio of 100 to 1000 to the compressional wave, the possible mechanism is discussed in detail.