Observation of ionospherically reflected quasiperiodic emissions by the DEMETER spacecraft

Miroslav Hanzelka (1, 2) , Ondřej Santolík (1, 2) , Mychajlo Hajoš (1) , František Němec (2) , Michel Parrot (3)

1 IAP - Institute of Atmospheric Physics [Prague]
2 Faculty of Mathematics and Physics [Praha/Prague]
3 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace

Quasiperiodic (QP) electromagnetic emissions are whistler mode waves at typical frequencies of a few kHz characterized by a periodic time modulation of their intensity. The DEMETER spacecraft observed events where the QP emissions exhibit a sudden change in the wave vector and Poynting vector directions. The change happens in a short interval of latitudes. We explain this behavior by ionospheric reflection and present a ray-tracing simulation which matches resulting wave vector directions. We also attempt to locate the source region of these emissions and conclude that they are most probably generated at the inner boundary of the plasmapause which also acts as a guide during the propagation of the QP emissions.

Domains: Sciences of the Universe [physics]

Miroslav Hanzelka, Ondřej Santolík, Mychajlo Hajoš, František Němec, Michel Parrot. Observation of ionospherically reflected quasiperiodic emissions by the DEMETER spacecraft. Geophysical Research Letters, 2017, 44 (17), pp.8721 - 8729. ⟨10.1002/2017GL074883⟩. ⟨insu-01619458⟩