Climatology of ionospheric amplitude scintillation on GNSS signals at south American sector during solar cycle 24

Scintillations are caused by ionospheric irregularities and can affect the propagation of trans-ionospheric radio
signals. One way to understand and predict the impact of such irregularities on Global Navigation Satellite
System (GNSS) signals is through the spatial/temporal characterization of the scintillation’s climatology during
different phases of a solar cycle covering different latitudes and longitudes. This characterization is performed
using amplitude scintillation index S4, during the full solar cycle 24, in the South American (SA) sector. The
investigation considers the diurnal, daily, and seasonal variation of S4 index for climatological purpose, and the
goal of this study is to investigate the scintillations covering a large spatial scale during the full solar cycle 24.
The characterization shows a latitudinal asymmetry, whereas at the south, the scintillations were more frequent
and their peak was more distant from the magnetic equator, which can be attributed by the South Atlantic
Magnetic Anomaly (SAMA), and/or by the transequatorial meridional neutral winds. It also shows a longitudinal
asymmetry, where the scintillations at the eastern sector occurred between November and February, while at the
western sector, they occurred during the months of October, November, February and March, which can be
attributed to the difference between the magnetic and geographic equators. The occurrence of scintillations
during two distinct geomagnetic storms with similar storm time in the SA sector is also presented.