The complex analysis of the largest geomagnetic storms of solar cycle #24 maximum
is our main
aim in this study. Our focus is on the ionosphere, more precisely on the ionospheric
F2-layer. The
selected storm intervals are: 11-17 November 2012 (Kpmax=6.33, Dstmin=-108 nT ), 16-23
March
2013 (Kpmax= 6.67, Dstmin=-132 nT ), and 16-25 March 2015 (Kpmax=7.67, Dstmin=-228
nT). Data from
6 digisonde (DPS4D) stations, ground GNSS TEC and Swarm satellite constellation have
been used
for the investigation.
This study is the next step to validate our previous results discussed in Berényi
et al. (2018). We
analyse the meridional behaviour of the geomagnetic disturbance caused ionospheric
storms to
understand and interpret the evolution of the caused effects.
The storm from 2012 is a no-positive phase (NPP) storm, but the 2013 and 2015 storms
show the
pattern of the regular positive phase (RPP) storm type (after the categorization by
Mendillo and
Narvaez, 2010). In all three cases a significant increase in electron density of the
F2-layer can be
observed at dawn/early morning (around 6:00 UT, 07:00 LT). We compared also the digisonde
foF2 parameter with the GNSS TEC data. Besides, we observed the fade-out of the ionospheric
layers at night during the geomagnetically disturbed time periods of storm 2012 and
2015. In
order to determine whether this fade-out is connected to the L-shell location of the
plasmapause
we analysed the Swarm observations (for the storm 2015), too.
