Velocity-Space Signatures of Ion Cyclotron Wave Resonance in the Earth’s Magnetosheath Plasma
Presentation Type
Poster
Presenter Format
In Person Meeting Talk
Topic
Dayside Science
Start Date
10-5-2022 5:30 PM
Abstract
Wave-particle interactions in collisionless plasmas are fundamental processes by which energy is transferred between electromagnetic waves and particles, resulting in the damping or growth of the waves. The correlation of the particle velocity distribution with the electric field measurements can exhibit different velocity-space signatures corresponding to the energy dissipation mechanism as well as the direction of energy transfer. Here we use MMS fields and ion distribution data to correlate the electric fields with the ion velocity distributions by way of the Field-Particle Correlation (FPC) technique. The high temporal cadence of the MMS FPI instrument suite allows us to observe signatures of ion cyclotron wave (ICW) resonance in velocity space. In a case study, we present the results of the FPC technique applied to a burst mode interval of data when the MMS satellites were in the Earth’s magnetosheath and ICW were present. This FPC analysis of ICW provides direct velocity-space evidence of this mechanism of energy transfer. In connection with prior results of electron Landau damping of kinetic Alfvén waves, the FPC technique can be used to identify the dominant mechanism of energy transfer present in an interval of data.
Velocity-Space Signatures of Ion Cyclotron Wave Resonance in the Earth’s Magnetosheath Plasma
Wave-particle interactions in collisionless plasmas are fundamental processes by which energy is transferred between electromagnetic waves and particles, resulting in the damping or growth of the waves. The correlation of the particle velocity distribution with the electric field measurements can exhibit different velocity-space signatures corresponding to the energy dissipation mechanism as well as the direction of energy transfer. Here we use MMS fields and ion distribution data to correlate the electric fields with the ion velocity distributions by way of the Field-Particle Correlation (FPC) technique. The high temporal cadence of the MMS FPI instrument suite allows us to observe signatures of ion cyclotron wave (ICW) resonance in velocity space. In a case study, we present the results of the FPC technique applied to a burst mode interval of data when the MMS satellites were in the Earth’s magnetosheath and ICW were present. This FPC analysis of ICW provides direct velocity-space evidence of this mechanism of energy transfer. In connection with prior results of electron Landau damping of kinetic Alfvén waves, the FPC technique can be used to identify the dominant mechanism of energy transfer present in an interval of data.
