An Observation of Kinetic Processes in Magnetosheath Turbulence using MMS Data

Characterizing the wave-particle interactions that lead to the dissipation of turbulence resulting in particle energization in the terrestrial magnetosheath provides the space physics community a better understanding of the microphysics of near-Earth space. Burst-mode data from the Magnetospheric Multiscale (MMS) mission's Flux Gate Magnetometers, Electric Field Double Probes, and Fast Plasma Investigation (FPI) from turbulent magnetosheath intervals is analyzed to characterize the energy density transfer rate between the fields and plasma particles. We use a novel Field Particle Correlation (FPC) technique to quantify the energy density transfer rate and identify where in velocity phase-space this energy transfer is occurring. The FPI measures full-sky velocity distributions in 30 ms for electrons and 150 ms for ions. This high temporal resolution allows us to observe fluctuations in the velocity distributions and correlate them with the electric field. The location of strong correlation in velocity-space indicates resonant wave-particle interactions, and the integral of this FPC over velocity yields the energy density transfer rate. The comparison between observed FPC velocity-space signatures from MMS data and simulations of dissipation processes in Alfvenic turbulence show which kinetic processes play a role in turbulent dissipation.