Journal article
EMIC waves observed by the low-altitude satellite DEMETER during the November 2004 magnetic storm
Journal of geophysical research. Space physics, Vol.120(7), pp.5455-5464
07/2015
DOI: 10.1002/2014JA020233
Abstract
This paper presents an analysis of ULF (0–20 Hz) waves observed by the low-altitude satellite Detection of ElectroMagnetic Emissions Transmitted from Earthquake Regions (DEMETER) during the magnetic storm of November 2004. Since these ULF waves are measured by both electric and magnetic antennas, they may be identified as electromagnetic ion cyclotron (EMIC) waves. While EMIC waves have been previously observed in the low-altitude ionosphere, this is the first time that they are observed for such extensive time periods and at such high frequencies. A common feature of these emissions is that their observation region in the low-altitude ionosphere extends continuously from the high-latitude southern trough in one side up to the high-latitude northern trough. The analysis of wave propagation points to the possible source region placed in the inner magnetosphere (L∼2–3). Observed wave frequencies indicate that waves must be generated much farther from the Earth compared to the satellite orbit. Exceptionally high frequencies of about 10 Hz can be explained by the source region placed in the deep inner magnetosphere at L ∼2.5. We hypothesize that these waves are generated below the local helium gyrofrequency and propagate over a large range of wave normal angles to reach low altitudes at L ∼1.11. In order to investigate this scenario, a future study based on ray tracing simulations will be necessary.
Details
- Title: Subtitle
- EMIC waves observed by the low-altitude satellite DEMETER during the November 2004 magnetic storm
- Creators
- D Píša - Czech Academy of Sciences, Institute of Atmospheric PhysicsMichel Parrot - French National Centre for Scientific ResearchO Santolík - Faculty of Mathematics and Physics [Praha/Prague]J. D. Menietti - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.120(7), pp.5455-5464
- Publisher
- American Geophysical Union/Wiley
- DOI
- 10.1002/2014JA020233
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Language
- English
- Date published
- 07/2015
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984627187002771
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