Feasibility study of detecting electron beam instability signatures in Incoherent Scatter Radar spectrum at high latitudes and the impact of this detection in the parameter estimation procedure.
Monday, 15 December 2014
An electron beam penetrating to the ionosphere can destabilize Langmuir waves and due to a cascade process destabilize Ion Acoustic waves. This beam also can produce the appearance of Langmuir Harmonics. These ionospheric plasma waves (Langmuir, Langmuir harmonics and ion acoustic) can be detected with Incoherent Scatter Radars (ISRs). In particular, enhanced ion acoustic waves are frequently observed at high latitude during Auroral events, which can be associated to electron precipitation. The enhanced ion acoustic waves might also have other possible drivers in addition to the penetrating electron beam. However, an electron beam is the only driver that might destabilize Langmuir and ion acoustic waves together with generating Langmuir harmonics. In this work we evaluate the feasibility of detecting generated Langmuir harmonic waves, in particular the first harmonic, with current ISRs. We also evaluate the impact that detecting those signatures (e.g. first Langmur harmonic wave) in the ISR's spectrum would have in the plasma and beam parameter estimation procedure. We propose some observational experiments with Sondrestrom and EISCAT, and report the obtained preliminary results.