Fig. 6From: Oxygen torus and its coincidence with EMIC wave in the deep inner magnetosphere: Van Allen Probe B and Arase observationsVan Allen Probe B/EMFISIS observations of a electron density at the satellite position, b average plasma mass, and c, d the dynamic power spectra of wave amplitudes in the directions perpendicular/parallel to the local magnetic field, during 02:10–03:10 UT on 12 September 2017. Data are the same as d, e, 5a, and b. White dots indicate the lower cutoff frequency (fco) of the emission of an electromagnetic ion cyclotron waveBack to article page