Abstract

This article examines magnetics clouds activity day’s occurrence as a function of the different phases of the solar cycle and the duration of their geoeffectiveness. The study period extends from cycle 11 to cycle 24. Magnetic clouds activity day’s occurrence were identified using pixel diagram from the years 1867 to 2019, that is to say, fourteen (14) solar cycles. The results show that in the study period: (1) there were 802 days of magnetic cloud activity with an effect lasting 1 day, 284 with an effect lasting 2 days and 141 having an effect three days; (2) the largest proportions of magnetic cloud activity days are recorded at maximum phase of the solar cycle, regardless of the type of magnetic cloud activity. These results also reveal that on average, there are 13 magnetic cloud activity days per year at the solar phase maximum.

Key words: Occurrences, pixel diagram, magnetic clouds, geoeffectivity.