North–South asymmetry of solar activity on a long timescale

Abstract

Based on the formulated hypothesis and the catalogs of low-latitude auroras, the time variations in the north–south (N–S) asymmetry of solar activity (SA) have been reconstructed for 2000 years, and its quasi-periodic composition and the relation to the activity level on long scales have been studied. It was found that the N–S asymmetry has quasi-periodic variations of 8–16 (the Schwabe cycle), 30–50 (the Bruckner cycle), 65–110 (the Gleissberg cycle), 150–210 (the Suess cycle), and 380–420 (the Link cycle) years. Although the periods of variations in the N–S asymmetry and the SA level are close to each other, it was shown that these parameters generally vary in antiphase and that the ranges of variations in the cycle duration are wider for the studied index.