Short-term periodicities in the north-south asymmetry of the Sun's surface rotation

Abstract

Power spectra of N-S asymmetries of the coefficients A and (j of the Sun's surface differential rotation determined from the Mt. Wilson velocity data during 1982-1994 suggest the existence of a period at 374 ± 30 day in the N-8 asymmetries of A and (j with> 99.9% confidence level. The spectrum of the N-S asymmetry of the coefficient lJ suggests existence of the periods at 374 ± 30 day, 78 ± 2 day and 49 ± 1 day in the N-S asymmetry of iJ with ~ 99% confidence level.