Latest Results on the Torsional Oscillation and Solar Cycle 25
Abstract
The Torsional Oscillation in the Sun is a zonal (East-West) flow that is slightly faster than the background differential rotation profile. The location of this flow slowly migrates in latitude over a period of several years. There are two branches of the flow: an equatorward branch that underlies the active regions, and a poleward branch. The timing of the equatorward migration is correlated with the timing of the solar cycle such that the activity for a cycle appears when the center of the flow reaches latitude 25 degrees. In addition, the poleward branch appears about 12 years prior to the activity for a cycle. Thus we should have observed the onset of Cycle 25 in 2008, but did not. This poster will update the observations to 2012, and present a new analysis that shows that the Cycle 25 flow appeared in 2010, but was hidden by a change in the background differential rotation profile. These results suggest that the next minimum will be two years longer than average, and that Cycle 25 will begin in 2022.
- Publication:
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American Astronomical Society Meeting Abstracts #220
- Pub Date:
- May 2012
- Bibcode:
- 2012AAS...22012302H