The interaction between ULF waves and thermal plasma ions at the plasmaspheric boundary layer during substorm activity

Abstract

(2015), The interaction between ULF waves and thermal plasma ions at the plasmaspheric boundary layer during substorm activity, J. Geophys. Res. Space Physics, 120, 1133-1143, doi:10.1002 Abstract During a substorm on 27 January 2004, energetic particle injections associated with ULF waves have been detected when Cluster fleet was traveling inbound in the Southern Hemisphere. Substorm-injected energetic particles are strong and clearly modulated by these ULF waves. The ULF waves with the period of 1 min are probably the third harmonic mode. The periodic pitch angle dispersion signatures at 5.2-6.9 keV energy channel were detected by Cluster satellite. These thermal plasma have high coherence with the electric field of the third harmonic poloidal mode and satisfy the drift-bounce resonant condition of N = 2. In addition, ion outflows from the Earth's ionosphere (tens to hundreds of eV) are also observed to be modulated by these ULF waves. To the best of our knowledge, this is the first report to show that ULF waves can simultaneously interact with both substorm-injected "hot" particles from the magnetotail and cold outflow ions from the Earth's ionosphere.

The interaction of ultra-low-frequency pc3-5 waves with charged particles in Earth’s magnetosphere

“…44 and 45 are the first to show simultaneous energetic electron drift-resonance and drift-bounce resonance with thermal ions in a fundamental poloidal mode standing wave in the inner magnetosphere. Third-harmonic ULF waves can also interact simultaneously with substorm-injected hot ions from the magnetotail, and cold ion outflow from the ionosphere (Ren et al 2015). This implies that fundamental mode poloidal ULF waves can also be excited by energetic electrons via drift-resonance.…”

“…The energy dissipated into the ionosphere by ULF waves is estimated to be 10 14 -10 15 W, or 30% of the substorm budget. ULF wave-modulated ionospheric ion outflow ranging from to hundreds of eV has been observed by Yang et al (2010a, b) and Ren et al (2015). What are the magnetospheric consequences of these ionospheric outflow ions that have extremely high fluxes?…”

Low‐Energy (<200 eV) Electron Acceleration by ULF Waves in the Plasmaspheric Boundary Layer: Van Allen Probes Observation

“…The drift‐bounce resonant condition for poloidal mode ULF waves can be described theoretically by Southwood et al () as where ω and m are the wave angular frequency and azimuthal wave number, respectively; ω d and ω b are the particle drift and bounce angular frequencies, respectively; N is an integer depending on the wave harmonic modes. For odd mode (e.g., fundamental mode, third harmonic mode), N = 0, ±2, ...; for even mode (e.g., second harmonic mode, fourth harmonic mode), N =± 1, ±3, ... (Ren et al, , ; Southwood & Kivelson, , ; Takahashi et al, ).…”

Ultralow Frequency Waves Deep Inside the Inner Magnetosphere Driven by Dipolarizing Flux Bundles

“…However, these works did not attribute the ULF waves to DFBs (or equivalently fast flows or plasma bubbles) per se. The particle acceleration by DFB‐related Pi2 waves was observed in a few cases at L = ~5 (Ren et al, ; Sergeev et al, ). In these cases the waves were either accompanied by DFBs or appeared immediately after the passing of DFBs, so the waves were locally excited instead of emanating at DFBs that had stopped elsewhere.…”