In situ evidence of the modification of the parallel propagation of EMIC waves by heated He <sup>+</sup> ions

Author
Keywords
Abstract
With observations of the Van Allen Probe B, we report in situ evidence of the modification of the parallel propagating electromagnetic ion cyclotron (EMIC) waves by heated He+ ions. In the outer boundary of the plasmasphere, accompanied with the He+ ion heating, the frequency bands of H+ and He+ for EMIC waves merged into each other, leading to the disappearance of a usual stop band between the gyrofrequency of He+ ions (ΩHe+) and the H+ cutoff frequency (ωH+co) in the cold plasma. Moreover, the dispersion relation for EMIC waves theoretically calculated with the observed plasma parameters also demonstrates that EMIC waves can indeed parallel propagate across ΩHe+. Therefore, the paper provides an in situ evidence of the modification of the parallel propagation of EMIC waves by heated He+ ions
Year of Publication
2016
Journal
Journal of Geophysical Research: Space Physics
Date Published
07/2016
URL
http://doi.wiley.com/10.1002/2016JA022573
DOI
10.1002/2016JA022573