TITLE:
Seasonal Variations of Solar Wind Parameters during Solar Cycles 23 and 24
AUTHORS:
Somaïla Koala, Yacouba Sawadogo, Jean Louis Zerbo
KEYWORDS:
Diurnal, Seasonal, Solar Winds, Parameters, Variation, Solar Cycle
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.12 No.9,
September
21,
2022
ABSTRACT: In this paper, we analyzed diurnal and
annual seasonal variations of solar wind parameters such as interplanetary
magnetic field (IMF), proton density (N), solar wind speed (V) and solar wind
dynamic pressure (Pdym), during the solar cycles 23 and 24. Our study shows
that strong geomagnetic disturbances are observed at the equinoxes during both
solar cycles. The highest proton densities are observed at solstices during
both solar cycles. The greatest solar wind speeds are observed at the equinoxes
of solar cycle 23 and at the solstices of solar cycle 24. The highest solar
wind dynamic pressures are observed at the solstices of both solar cycles. We
also observed an asymmetrical evolution of the seasonal diurnal values of the
solar wind parameters during the two cycles, except for the proton density. Our
investigations also highlight the fact that the seasonal diurnal values of the
solar wind parameters are significant at solar cycle 23 compared to solar cycle
24 characterized by a global weak in solar plasma conditions since the deep
minimum that followed the solar cycle 23 leading to an absence of a persistent
polar coronal hole. The drop observed in polar field and solar winds parameters
during solar cycle 24 is reproduced on seasons (solstices and equinoxes). The
solar cycle 23 and 24 appear to be two magnetically opposite solar cycles
regardless the time scales.