Pc1 pulsations are important to consider for the interpretation of wave-particle interactions in the Earth’s magnetosphere. In fact, the wave properties of these pulsations change dynamically when they propagate from the source region in the space to the ground. A detailed study of the wave features can help understanding their time evolution mechanisms. In this study, we statistically analyzed Pc1 pulsations observed by a Bohyunsan (BOH) magneto-impedance (MI) sensor located in Korea (L = 1.3) for ~one solar cycle (November 2009-August 2018). In particular, we investigated the temporal occurrence ratio of Pc1 pulsations (considering seasonal, diurnal, and annual variations in the solar cycle), their wave properties (e.g., duration, peak frequency, and bandwidth), and their relationship with geomagnetic activities by considering the Kp and Dst indices in correspondence of the Pc1 pulsation events. We found that the Pc1 waves frequently occurred in March in the dawn (1-3 magnetic local time (MLT)) sector, during the declining phase of the solar cycle. They generally continued for 2-5 minutes, reaching a peak frequency of ~0.9 Hz. Finally, most of the pulsations have strong dependence on the geomagnetic storm and observed during the early recovery phase of the geomagnetic storm.

1. INTRODUCTION
2. DATA AND ANALYSIS
    2.1 Instruments and Data
    2.2 Wave Detection Algorithm
3. RESULTS
    3.1 Temporal Variation
    3.2 Properties of the Pc1 Waves
4. DISCUSSION
5. CONCLUSION AND SUMMARY
REFERENCES

• Jiwoo Kim(Department of Astronomy, Space Science and Geology, Chungnam National University)
• Junga Hwang(Korea Astronomy and Space Science Institute, Korea University of Science and Technology) Corresponding Author
• Hyangpyo Kim(Institute for Earth-Space Environmental Research, Nagoya University)
• Yu Yi(Department of Astronomy, Space Science and Geology, Chungnam National University)