Plasma fluctuations at the flanks of the Earth's magnetosheath at ion kinetic scales
We present a statistical study of the magnetosheath plasma fluctuation spectra at a high-frequency range (with frequencies from 0.01 to 10 Hz). Variations of ion flux value and its direction are considered. The direction of ion flux is characterized by a polar angle – the deviation of the ion fl...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-11-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/34/1011/2016/angeo-34-1011-2016.pdf |
| Summary: | We present a statistical study of the magnetosheath plasma fluctuation
spectra at a high-frequency range (with frequencies from 0.01 to 10 Hz).
Variations of ion flux value and its direction are considered. The direction
of ion flux is characterized by a polar angle – the deviation of the ion
flux vector from the Sun–Earth line. We consider 290 Fourier's spectra that
can be described by two power laws with a break, i.e., a change of slope. The
ion flux fluctuation spectra are shown to have breaks at higher frequencies
compared to the polar angle spectra. We compare the frequency of the break
with the gyrostructure frequency for a number of cases. We show the polar
angle break frequency to usually be smaller than the gyrostructure frequency.
The dependencies of spectrum parameters such as the slopes and the break
frequency on plasma parameters are also considered. |
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| ISSN: | 0992-7689 1432-0576 |