Whistler waves above the lower hybrid frequency in the ionosphere and their counterparts in the magnetosphere

In this study, we report the statistical properties of whistler mode low hybrid (LH) emissions in the ionosphere, which have structureless spectra with a lower frequency boundary that matches the variation of the local lower hybrid resonance frequency fLHR. A potential source for the low hybrid emissions is identified as the high-frequency plasmaspheric hiss (HFPH) in the magnetosphere. We use DEMETER and Van Allen Probes data to perform a statistical study of the wave power distribution of the LH emissions and HFPH. Both LH and HFPH emissions show a similar frequency range, a similar invariant magnetic latitude range, and have similar trends in magnetic local time (MLT) (stronger wave intensity on the dayside) and in the AE index (stronger wave intensity for higher AE condition). A ray tracing simulation is also performed to demonstrate the propagation of HFPH waves from the magnetosphere into the ionosphere as LH waves.

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