Akademik Veri Yönetim Sistemi
44th COSPAR Scientific Assembly 2022, Athens, Yunanistan, 16 - 24 Temmuz 2022, ss.2-3
The sun has an active role in the Earth’s magnetosphere and ionosphere. Especially geomagnetic storms that occur due to solar activity not only play a role in shaping the Earth’s
magnetosphere but also cause ionospheric changes depending on the level of the storm. Thus,
the changes caused by solar activity are also responsible for the variable and dynamic structure
of the Earth’s Ionosphere, which is a natural plasma laboratory. One of the most important
components of this dynamic region is magnetopause. The magnetopause is the boundary region that separates the magnetospheric plasma from the solar wind plasma by balancing the
dynamic pressure of the solar wind and the magnetic pressure of the magnetosphere, formed
during the interaction of the solar winds with the earth’s magnetic field. The ionosphere is
a layer of the atmosphere located at an altitude of about 60 km to 1100 km from the Earth,
consisting of a natural plasma formed by gases ionized by solar radiation, and is very important
for radio wave propagation. The dynamic structure and physics of the ionosphere depend on
solar events, geomagnetic storms, solar cycle, UV radiation from the Sun, day or night, season,
and geographical location. It has three basic layers, called D, E, and F, but the layer with
the highest ionization is also the F layer, which is the highest. During the day, the F layer
develops an additional layer called F1, which is relatively weak under the influence of the D
and E layers. The permanently existing layer is called F2 and is responsible for the refraction,
reflection, propagation, and transmission of radio waves. In the study of the F2 layer, hmF2,
which is the peak electron density height of the F2 layer, is most often used. Understanding
the ionosphere and the mechanisms that cause ionospheric decay is crucial to understanding
key features of our Earth’s near space. The solar wind and magnetosphere couplings have been
studied for a long time, and thanks to these studies, we can interpret the geomagnetic storms
created by different flows. Also, since the magnetopause, magnetosphere, and ionosphere are
formed by the same field lines, it can be said that there will be an exchange of momentum and
energy between these different regions, thus the regions will enter into various interactions with
each other. However, we need more information on magnetosphere-ionosphere coupling, which
is extremely critical for the low-orbit satellites around the Earth. To better understand the
solar wind magnetosphere-ionosphere couplings, the different conditions should be thoroughly
investigated by both simulations and real observations. As a result of studies on this subject, the
response of the magnetosphere and the ionosphere to different factors will be better predicted.
We studied the behavior of this geomagnetic storm moment five days before and after by
calculating the magnetopause distance from ö Chapman and Ferraro’s formula using NASA’s
WIND satellite. We compared our results with hmF2 data from seven different GIRO ionosonde
stations with IF843, PA836, BC840, AU930, PRJ18, BVJ03, and SMK29 URSI codes located
at Central and Equatorial geomagnetic latitudes of North and South America. We compared
the values of the hmF2 layer with the median of the same hours of the previous fifteen days.
In addition, by examining the rate of change of the magnetopause and hmF2 layers together,
we were able to more clearly identify the simultaneous increases and decreases. According to
the results we found from our analysis, we found an instantaneous compression followed by a
prolonged uplift behavior in the measured hmF2 heights at all stations studied by the onset
of the geomagnetic storm. As the magnetopause approaches earth, particularly in the middle
of the geomagnetic storm, we observed a sustained high-amplitude hmF2 oscillation. These
moments coincide especially with the times when the geomagnetic storm is at its strongest. We
discovered that as the impact of the geomagnetic storm began to wane, similarly oscillations
repeated with smaller amplitudes, decreasing for the last time and returning to normal in the
storm’s final moments.