Solar terminator and corresponding variability within ionospheric plasma

0497726 - ÚFA 2019 BE eng A - Abstract
Koucká Knížová, Petra - Potužníková, Kateřina - Kouba, Daniel - Boška, Josef - Mošna, Zbyšek - Obrazová, Dalia
Solar terminator and corresponding variability within ionospheric plasma.
15th European Space Weather Week. Brussels: STCE, 2018.
[European Space Weather Week /15./. 05.11.2018-09.11.2018, Leuven]
Institutional support: RVO:68378289
Keywords : ionosphere * ionosphere * acoustic-gravity waves * solar terminator
OECD category: Meteorology and atmospheric sciences
http://www.stce.be/esww15/program/session_details.php?nr=12#

The Ionosphere is highly variable system that shows oscillations on wide range of scales. Observed wave-like disturbances are caused by variety of sources from above and below. Sun and magnetosphere are considered to the most important drivers. However, the forcing from below by processes in the lower-laying atmospheric regions cannot be omitted. The oscillation within ionospheric plasma can be detected on a broad scales ranging from acoustic and gravity waves to oscillations on periods corresponding to solar cycles. Within the ionospheric variability, the Acoustic-Gravity Waves (AGW) play an important role. They are present in the atmosphere and ionosphere all the time and their attribution to the particular source still remains an open task. The AGWs, their sources, persistence, propagation, are systematically studied since sixties last century. Solar Terminator has been identified as an important source of AGW in the Earth atmosphere-ionosphere system. The cooling/heating of the Earth’s atmosphere induced by decrease/increase of the incoming solar radiation is a potential generator of the wave/like disturbances that are likely to propagate through the atmosphere-ionosphere system. Due to the systematic occurrence of AGWs during sunrise and sunset, it has been proven experimentally, that the moving region of atmospheric constituents with large gradients acts a source of AGW structures. However, the variability in periodicity and persistence of AGWs is very large and the observational techniques limited. The presentation focuses on Solar Terminator and related ionospheric variability as observed by ground based measurements in Midlatitudes.
Permanent Link: http://hdl.handle.net/11104/0290237