The Distribution and Evolution of Storm Time Pc3‐5 ULF Wave Power Based on Satellite and Ground Observations

Abstract

AbstractThe geomagnetic storm is an intense geomagnetic activity, and one important research aspect is the storm time ultralow frequency (ULF) waves, which can resonate with injected particles and impact particle dynamics in the inner magnetosphere. This study focuses on analyzing ULF wave power during geomagnetic storms on the ground, in the magnetosphere and in the solar wind. During the Van Allen Probe era from year 2012–2019, we identified 94 geomagnetic storm events with 25 as strong storms and 69 as moderate storms based on the variation of SYM‐H index. The analysis revealed that for both satellite and ground‐based measurements during storms with different intensity, the ULF wave power was dramatically enhanced in the main phase. In addition, the ULF wave power of strong storms was significantly stronger than that of moderate storms within the magnetosphere and on the ground. While the finding is opposite in the solar wind. Furthermore, the ULF wave power of strong storms exhibited a higher intensity at higher L shell values and in some cases, it can last up to ∼2 days. Besides, the ULF wave power displayed a linear correlation with the absolute value of the SYM‐H index during the storm main phase while it exhibited an exponential association with the absolute value of the SYM‐H index during the recovery phase. This comprehensive analysis offers valuable insights into the evolution of ULF waves in the inner magnetosphere during geomagnetic storm events, shedding light on plasma waves and wave‐particle interactions in this region.