Low-altitude frequency-banded equatorial emissions observed below the electron cyclotron frequency - Archive ouverte HAL Access content directly
Journal Articles Annales Geophysicae Year : 2020

Low-altitude frequency-banded equatorial emissions observed below the electron cyclotron frequency

(1) , (2) , (3) , (4) , (1) , (1) , (1) , (1) , (5)
1
2
3
4
5

Abstract

The ICE (Instrument Champ Électrique) experiment on board the DEMETER (Detection of ElectroMagnetic Emissions Transmitted from Earthquake Regions) satellite recorded frequency-banded wave emissions below the electron cyclotron frequency, with band spacing frequency low-hybrid resonance, in the vicinity of the magnetic equatorial plane. Those radiations were observed in the beginning of the year 2010 on the night side of Earth and rarely on the day side. We distinguish two components: one appears as frequency bands continuous in time between a few kilohertz and up to 50 kHz, and the other one is from 50 to 800 kHz. The first component exhibits positive and negative frequency drift rates in the Southern Hemisphere and Northern Hemisphere, at latitudes between 40 and 20 •. The second one displays multiple spaced frequency bands. Such bands mainly occur near the magnetic equatorial plane with a particular enhancement of the power level when the satellite latitude is close to the magnetic equatorial plane. We show in this study the similarities and the discrepancies between the non-free-space DEMETER frequency-banded emissions and the well-known free-space terrestrial kilometric radiation. The hollow cones of the DEMETER frequency-banded wave emissions are oriented towards Earth's ionosphere. We suggest that the source region is localized in regions pole-ward of the plasmapause where the ratio of the plasma frequency to gyro-frequency is smaller than one.
Fichier principal
Vignette du fichier
angeo-38-765-2020.pdf (5.95 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

insu-02885146 , version 1 (30-06-2020)

Identifiers

Cite

Mohammed Y. Boudjada, Patrick H. M. Galopeau, Sami Sawas, Valery Denisenko, Konrad Schwingenschuh, et al.. Low-altitude frequency-banded equatorial emissions observed below the electron cyclotron frequency. Annales Geophysicae, 2020, 38, pp.765-774. ⟨10.5194/angeo-38-765-2020⟩. ⟨insu-02885146⟩
113 View
87 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More