Frequency of Occurrence of Solar Plasma Disturbances in Interplanetary Space

Abstract Major solar plasma disturbances are subjected to Lomb–Scargle periodogram and wavelet analysis to determine the occurrence frequency. These disruptions include interplanetary coronal mass ejection, sudden storm commencement, high-speed streams, corotating interaction regions, interplanetary shocks and Forbush decreases. We included information on all of the aforementioned solar disturbances for the last six solar cycles, from 1965 to 2023, for this study. Our findings reveal some intriguing and noteworthy results that clearly distinguish between even and odd-numbered solar cycles. The study suggests that the Sun behaves differently in odd and even-numbered solar cycles as it comes from the massive solar eruptions. During even-numbered solar cycles, variations with a period of ∼44 days are prominently observed in addition to solar rotation (∼27 days) and extended solar (∼36 days) rotation. However, in addition to solar rotation, prolonged solar rotation, and periods of around 44 days, we also detect a number of intermittent changes with nearly comparable amplitude during the odd-numbered solar cycles. The findings also demonstrate that, in contrast to odd-numbered solar cycles, the emissions rate of these disruptions is more distinct and predictable during even-numbered solar cycles.