Solar Terminator and Its Signatures in the Ionospheric Plasma

0493143 - ÚFA 2019 BG eng A - Abstrakt
Koucká Knížová, Petra - Kouba, Daniel - Mošna, Zbyšek - Boška, Josef - Obrazová, Dalia
Solar Terminator and Its Signatures in the Ionospheric Plasma.
Book of Abstracts: Tenth Workshop "Solar Influences on the Magnetosphere, Ionosphere and Atmosphere". Sofia: Space Research and Technology Institute, Bulgarian Academy of Sciences, 2018 - (Georgieva, K.). s. 33-33
[Workshop "Solar Influences on the Magnetosphere, Ionosphere and Atmosphere" /10th/. 04.06.2018-08.06.2018, Primorsko]
Institucionální podpora: RVO:68378289
Klíčová slova: Solar Terminator * inospheric plasma * wave-like structures * vertical ionospheric sounding
Obor OECD: Meteorology and atmospheric sciences
http://ws-sozopol.stil.bas.bg/

Solar Terminator is defined as a border region between sunlit and dark atmosphere. It is
characterized by sharp change in the intensity of the incoming solar radiation and consequently
by gradients within atmospheric plasma parameters. Solar Terminator moves through the
atmosphere with the rotation of the Earth inducing wave-like disturbances in the ionospheric
plasma. The excited wave-like structures belong to the Acoustic-Gravity waves domain. The
AGW, their sources, persistence, propagation, are systematically studied since sixties. They are
permanently present in the atmosphere and ionosphere causing significant part of the ionospheric
variability. However, their attribution to the particular source still remains an open task.
Solar Terminator (ST) has been identified as an important source of AGW in the Earth
atmosphere-ionosphere system. The generation mechanism has been proposed by Chimonas and
Hines in seventies. 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 in sampling rates etc.
The contribution focuses on the wave-like structures detected at ionospheric heights that
can be potentially attributed to the motion of the Solar Terminator. Data used for analyses are
obtained from vertical ionospheric sounding.

Trvalý link: http://hdl.handle.net/11104/0286569