资源环境科技发展态势分析平台

We investigate a significant duskside ionospheric density modulation in the Pc5 frequency band and related spatial structures during the storm on May 28, 2017. We take advantage of 3D ionospheric observations by the PFISR and simultaneous magnetospheric in situ observations. Inversion of the density suggests that the Pc5 pulsations modulated precipitating electrons over a broad range of energies (~5 keV‐500 keV). Such strong electron precipitation likely caused a significant density modulation rate of ~ 8 and ionospheric Pedersen and Hall conductances to vary rapidly and peaked at approximately 70‐100 S. The reflection coefficient was also substantially modulated between 0.5 and 0.9. Moreover, the observations by the multi‐beam PFISR and THEMIS E both reveal that the Pc5 pulsations propagated westward in the duskside region. It suggests that quasi‐periodic activities in the nightside and subsequent duskward drifts were likely the source of the duskside Pc5 pulsations.