Ionospheric Plasma Density Oscillation Related to EMIC Pc1 Waves
Abstract
We report the first observation of plasma density oscillations coherent with magnetic Pc1 waves. Swarm satellites observed compressional Pc1 wave activity in the 0.5–3 Hz band, which was coherent with in situ plasma density oscillations. Around the Pc1 event location, the Antarctic Neumayer Station III (L ~ 4.2) recorded similar Pc1 events in the horizontal component while NOAA‐15 observed isolated proton precipitations at energies above 30 keV. All these observations support that the compressional Pc1 waves at Swarm are oscillations converted from electromagnetic ion cyclotron (EMIC) waves coming from the magnetosphere. The magnetic field and plasma density oscillate in‐phase. We compared the amplitudes of density and magnetic field oscillations normalized to background values and found that the density power is much larger than the magnetic field power. This difference cannot be explained by a simple magnetohydrodynamic (MHD) model, although steep horizontal/vertical gradients of background ionospheric density can partly reconcile the discrepancy.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 03, 2020
- Source ID
- 10.1029/2020gl089000
Entities
People
- Claudia Stolle
- Hyangpyo Kim
- Jaeheung Park
- Junga Hwang
- Jürgen Matzka
- Kazuo Shiokawa
- Khan-Hyuk Kim
- Stephan Buchert
- Tanja Fromm
- Yoshizumi Miyoshi
- Yukinaga Miyashita
Organizations
- Air Force Office of Scientific Research
- GFZ Helmholtz Centre for Geosciences
- Japan Society for the Promotion of Science
- Korea Astronomy and Space Science Institute
- Korea University of Science and Technology
- Kyung Hee University
- Nagoya University
- National Research Foundation of Korea
- Swedish Institute of Space Physics