`1.3-Year' and `153-day' Periodicities in the Sun's Surface Rotation

Abstract

Using the daily Mt. Wilson velocity data during 1986-1994, we found 1.3 ± 0.1 yr periodicity - is dominant in the Sun's surface `mean' rotation rate (A ) during 1986-1994 (solar cycle 22). A 153 ± 5 - day periodicity found to be substantially significant in A during the decay phase of solar cycle 22.