Simultaneous measurements of quasi-periodic emissions by spacecraft and ground-based instruments

0446696 - ÚFA 2016 CZ eng A - Abstrakt
Bezděková, B. - Němec, F. - Manninen, J. - Parrot, M. - Hayosh, Mykhaylo - Santolík, Ondřej - Macúšová, Eva
Simultaneous measurements of quasi-periodic emissions by spacecraft and ground-based instruments.
26th IUGG General Assembly 2015. Earth and Environmental Sciences for Future Generations : abstracts. Prague: International Union of Geodesy and Geophysics, 2015. A21p-258.
[Earth and Environmental Sciences for Future Generations. General Assembly of International Union of Geodesy and Geophysics /26./. 22.06.2015-02.07.2015, Prague]
Institucionální podpora: RVO:68378289
Klíčová slova: magnetosphere * quasi-periodic emissions
Kód oboru RIV: DG - Vědy o atmosféře, meteorologie
http://www.iugg2015prague.com/abstractcd/data/HtmlApp/main.html#1

Electromagnetic waves at frequencies between about 0.5 and 4 kHz observed in the inner magnetosphere sometimes exhibit a periodic time modulation of the wave intensity. Such events are typically called quasi-periodic (QP) emissions,and they can be observed both by satellite and ground-based instruments. They are primarily dayside phenomenon, and their generation mechanism appears to be(at least in some cases) related to compressional ULF pulsations of the magnetic field, which periodically modulate resonant conditions of the wavegrowth in the wave generation region. We use simultaneous measurements of QP emissions by the French low-altitude satellite DEMETER and by ground-based instruments operated by Sodankyla Geophysical Observatory in Finland. These conjugate observations allow us to estimate spatial dimensions and time duration of the analyzed events. Moreover, we perform a detailed analysis of an exceptional QP event which lasted for more than 10 hours and was observed in 8 consecutive DEMETER half-orbits. We also discuss the propagation of the events from their source region down to low altitudes.
Trvalý link: http://hdl.handle.net/11104/0248921