Large‐Amplitude Electromagnetic Ion Cyclotron Waves and Density Fluctuations in the Earth's Magnetosheath
The Earth's Magnetosheath is a region slowing down high‐speed particles originating from the solar wind, protecting the Earth from the hazards of high‐energy charged particles. A considerable fraction of the energy of energetic particles is transferred into plasma waves.
Using measurements by Magnetospheric Multiscale mission,Dr.Jinsong Zhao from the Purple Mountain Observatory and his collaborators found an observational event of large‐amplitude low‐frequency electromagnetic ion cyclotron waves lasting nearly 6 hr, propagating from the outer magnetosheath to the inner magnetosheath. Density fluctuations are found to coexist with these electromagnetic waves. Applying the measurements of charged particles to modeling, they showed the observed waves are likely excited by free energy provided by ions with an anisotropic temperature distribution, consistent with wave theory.
This work has been published in GRL.