| Abstrakt: |
Both the net torsional pattern and its derivative, the shear oscillation, are studied in relation to the solar activity cycle using data collected at Mount Wilson from 1967–1986. The shear is seen as the better quantity for study, since it is both more fully determinable with these data and has straighter ties to the zones of activity. The shear zones run from pole to equator, clearly indicating that the cycle begins at the poles. Total transit, roughly at constant speed, takes roughly 18 years, and the active zones emerge to span the zones of shear enhancement after the latter have reached sunspot latitudes. This 18-yr transit time is seen as the proper duration of the cycle: successive cycles begin roughly 11 years apart and thus overlap. The polar origin of the torsional pattern is found to be phenomenologically connected with variations in the polar field amplitude. It is also noted in both the magnetic and torsional patterns that, for the past few cycles, the activity portion begins earlier and thus lasts longer in the northern hemisphere. |
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