A case study of non-resonant mode three-second ULF waves observed by MMS
Abstract
We investigate 3-s ultra-low frequency (ULF) waves using MMS observations. By combining the plasma rest frame wave properties obtained from multiple methods with the instability analysis based on the velocity distribution in the linear wave stage, the ULF wave is determined to be due to the ion/ion non-resonant mode instability. The interaction between the wave and ions is analyzed using the phase relationship between the transverse wave fields and ion velocities, and using the longitudinal momentum equation. During the stage when ULF waves have sinusoidal waveforms up to |dB|/|B0|~3, where B0 is the background magnetic field, the electric fields perpendicular to B0 do negative work to solar wind ions, while along B0, that is stronger than the electric field leads to solar wind ion deceleration; the beam ions gain energy. The ULF wave leads to electron heating, preferentially in the direction perpendicular to the local magnetic field. Secondary waves are generated within the ULF waveforms, including whistler waves near half of the electron cyclotron frequency, high-frequency electrostatic waves, and magnetosonic whistler waves. The work improves the understanding of the nature of 3-s ULF waves and the associated wave-particle interaction.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMSM0170002W
- Keywords:
-
- 2724 Magnetopause and boundary layers;
- MAGNETOSPHERIC PHYSICS;
- 2740 Magnetospheric configuration and dynamics;
- MAGNETOSPHERIC PHYSICS;
- 2756 Planetary magnetospheres;
- MAGNETOSPHERIC PHYSICS;
- 2784 Solar wind/magnetosphere interactions;
- MAGNETOSPHERIC PHYSICS