ANGEOD Annales Geophysicae Discussions ANGEOD Ann. Geophys. Discuss. 2568-6402 Göttingen, Germany 10.5194/angeo-2018-119 Non-linear Effects in Electromagnetic Wave Activity Observed in the RELEC Experiment on-board Vernov Mission Panasyuk Mikhail I. 1 2 Svertilov Sergey I. 1 2 Klimov Stanislav I. 3 Grushin Valery A. 3 Novikov Denis I. 3 Ruzhin Yuri Y. 4 Mikhailov Yuri M. 4 Ferencz Csaba 6 Szegedi Peter 7 Korepanov Valery E. https://orcid.org/0000-0001-8260-1720 5 Bogomolov Vitaly V. 1 2 Garipov Gali K. https://orcid.org/0000-0001-8409-6799 1 Belyayev Serhiy V. 5 Demidov Olexander N. 5 M. V. Lomonosov Moscow State University, D. V. Skobeltsyn Institute of Nuclear Physics M. V. Lomonosov Moscow State University, Physics Department Space Research Institute, Russian Academy of Science, Moscow, Russia N. V. Puchkov Institute of the Earth magnetism, Ionosphere and radio-wave propagation, Russian Academy of Science, Troitsk, Russia Institute of Space Research, Ukrainian Academy of Science and National Space Agency, Lviv, Ukraina Eötvös University, Space Research Group, Budapest, Hungary BL Electronics Ltd., Solymár, Hungary 15 11 2018 2018 1 15 Copyright: © 2018 Mikhail I. Panasyuk et al. 2018 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://angeo.copernicus.org/preprints/angeo-2018-119/ The full text article is available as a PDF file from https://angeo.copernicus.org/preprints/angeo-2018-119/angeo-2018-119.pdf

<p>The experiments on-board Vernov satellite were aimed on the study of high energy (relativistic and sub-relativistic) electron acceleration and losses in the trapped radiation areas as well as high altitude electric discharges in the upper Atmosphere. A separate task was study electromagnetic-wave phenomena in the near Earth space and the upper Atmosphere. During observations on 10 December 2014 interesting phenomena were discovered. They are connected to non-linear effects in wave activity of the type of two or three wave decays as well as splitting into two wave structures. Whistlers with specific unusual temporal structure of swallowtail type were observed on the spectral diagrams (sonograms), which were obtained for this time. It was shown that such signals can be caused by seismic activity. The signals of the type of whistler with long tail were also observed. Such signals were also detected by ground stations.</p>