Ionospheric Modulation by Storm Time Pc5 ULF Pulsations and the Structure Detected by PFISR‐THEMIS Conjunction. Issue 16 (21st August 2020)

• Record Type: Journal Article
• Authors: Wang, Boyi; Nishimura, Yukitoshi; Hartinger, Michael; Sivadas, Nithin; Lyons, Larry L.; Varney, Roger H.; Angelopoulos, Vassilis
• Is Part Of: Geophysical research letters. Volume 47:Issue 16(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-21
• Subjects: ULF wave -- conductance -- ISR -- THEMIS -- storm -- precipitation; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1029/2020GL089060
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We investigate a significant duskside ionospheric density modulation in the Pc5 frequency band and related spatial structures during the storm on 28 May 2017. We take advantage of 3‐D 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 (~5–500 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 ~70–100 S. The reflection coefficient was also substantially modulated between 0.5 and 0.9. Moreover, the observations by the multibeam PFISR and THEMIS E both reveal that the Pc5 pulsations propagated westward in the duskside region. It suggests that quasiperiodic activities in the nightside and subsequent duskward drifts were likely the source of the duskside Pc5 pulsations. Key Points: Plasma density in the D and E regions was dramatically modulated by 8 times the background by Pc5 ULF waves during the storm Density changes caused significant increases of Pedersen and Hall conductances and reflection coefficient Such strong ionospheric modulation likely relates to quasiperiodic precipitation from the nightside