Observational study of ionosphere TEC fluctuations triggered by interplanetary shock

Abstract

<p indent=0mm>Interplanetary shocks can cause violent disturbances in near-earth space. In this paper, we use high time-resolution <sc>(1 s)</sc> data from ground-based global position system (GPS) receivers to analyze the perturbations of ionosphere total electron content (TEC) when an interplanetary shock impacted the Earth’s magnetosphere on March 17, 2015. We found that after the shock arrived at the Earth, TEC perturbations demonstrated the characteristics of ULF waves, and the fluctuation characteristics were different in different latitude regions. The amplitude of TEC fluctuations observed by the receivers in the polar region was approximately 0.4 TECU, which lasted for more than <sc>10 min,</sc> and the fluctuation period was 2 to <sc>3 min,</sc> which increased with the increasing latitude of the pierce point. The amplitude of the TEC fluctuations observed by the receivers in middle and low latitude areas was approximately 0.2 TECU, which lasted for 5 to <sc>10 min,</sc> and the fluctuation period was approximately 2 min. We suggest that the existence of plasmasphere may be the reason for such difference in TEC fluctuations, and that the TEC fluctuations in polar regions may be related to field line resonances. The TEC fluctuations in the middle and low latitude areas may be related to cavity mode oscillations. We used GPS TEC technology to detect ionosphere TEC fluctuations triggered by interplanetary shock, which can help us further understand the nature of ULF waves in the Earth’s magnetospheric-ionospheric system and can further demonstrate the important role of GPS TEC technology in the study of the near-earth space environment.