MMS observations of ion cyclotron waves in the solar wind and their indications of source ions
Presentation Type
Talk
Presenter Format
In Person Meeting Talk
Topic
Dayside Science
Start Date
10-5-2022 4:15 PM
Abstract
Electromagnetic waves near the proton cyclotron frequency are frequently observed in the solar wind at multiple heliocentric distances. These so-called ion cyclotron waves play important roles in transferring energies and mediating the level of temperature anisotropy of ions. The wave-particle interaction in this frequency range is of high interest to solar wind turbulence studies, because the ion kinetic scale lies in the transition from the inertial range to the sub-ion dissipation range. The Magnetospheric Multiscale (MMS) spacecraft orbits in “pristine” solar wind near apogee which provides high-resolution plasma and fields measurements to advance our understanding of the wave properties and the wave-particle interactions at the ion kinetic scale. The recent studies of Parker Solar Probe data and the MMS data suggest ion beams to be one of the major sources for generating these circularly polarized and field-aligned propagating waves. Hybrid simulations suggest that both super-Alfvenic relative drift of and unstable ion temperature anisotropy could be the possible source of these widely observed waves (from 0.1 to 1 AU) in the heliosphere.
MMS observations of ion cyclotron waves in the solar wind and their indications of source ions
Electromagnetic waves near the proton cyclotron frequency are frequently observed in the solar wind at multiple heliocentric distances. These so-called ion cyclotron waves play important roles in transferring energies and mediating the level of temperature anisotropy of ions. The wave-particle interaction in this frequency range is of high interest to solar wind turbulence studies, because the ion kinetic scale lies in the transition from the inertial range to the sub-ion dissipation range. The Magnetospheric Multiscale (MMS) spacecraft orbits in “pristine” solar wind near apogee which provides high-resolution plasma and fields measurements to advance our understanding of the wave properties and the wave-particle interactions at the ion kinetic scale. The recent studies of Parker Solar Probe data and the MMS data suggest ion beams to be one of the major sources for generating these circularly polarized and field-aligned propagating waves. Hybrid simulations suggest that both super-Alfvenic relative drift of and unstable ion temperature anisotropy could be the possible source of these widely observed waves (from 0.1 to 1 AU) in the heliosphere.
