Figure 2: Electromagnetic power spectral densities of high-frequency and very-low-frequency waves.
From: Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons
(a,c) Wave electric power spectral density from the high-frequency receiver (HFR) of the EMFISIS Suite and Integrated Science suite. The upper hybrid resonance bands (bright lines) had frequencies (positively correlated with the background electron density59) beyond 70 kHz, indicating that the twin spacecrafts stayed in the high-density plasmasphere for the entire orbits. (b,d) Wave magnetic power spectral density from the Waveform Receiver (WFR) of the EMFISIS suite. There were VLF hiss waves in the frequency range 0.1–1.0 kHz contributing to the slow loss of relativistic electrons, but no VLF chorus waves responsible for the local acceleration of relativistic electrons.
