http://arxiv.org/abs/1809.10776
Torsional oscillations represent bands of fast and slow zonal flows around the Sun, which extend into the deep convection zone and migrate during solar cycles towards the equator following the sunspot butterfly diagram. Principal component analysis of helioseismology data obtained in 1996-2018 for almost two solar cycles reveals zones of deceleration of the torsional oscillations inside the Sun due to back reaction of dynamo-generated magnetic field. The zonal deceleration originates in the solar tachocline at high latitudes, and migrates through the convection zone revealing patterns of magnetic dynamo waves predicted by the Parker’s dynamo theory. The analysis reveals that the primary seat of the solar dynamo is located in a high-latitude zone of the tachocline. It explains the phenomenon of the extended solar cycle observed in the evolving shape of the solar corona, and why the polar magnetic field strength predicts the solar maxima. The results show a substantial decrease of the zonal acceleration in the current solar cycle and predict further decline of sunspot activity in the next solar cycle.
A. Kosovichev and V. Pipin
Mon, 1 Oct 18
9/46
Comments: 15 pages, 9 figures
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