The 1̃50 day quasi-periodicity in interplanetary and solar phenomena during cycle 23

Abstract

An intermittent quasi-periodicity of ∼150 days in various solar and interplanetary phenomena has been reported in earlier solar cycles. We suggest that variations in the occurrence of solar energetic particle events, interplanetary coronal mass ejections, and geomagnetic storm sudden commencements during solar cycle 23 show evidence of this quasi-periodicity, which is also present in the sunspot number, in particular in the northern solar hemisphere. It is not, however, prominent in the interplanetary magnetic field strength. Copyright 2005 by the American Geophysical Union.