Torsional Oscillations: Vorticity; Solar Cycle Predictions

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The azimuthal wind bands known as the torsional oscillations have been revealed primarily by studying the longitudinally averaged solar rotation over a period spanning several full solar rotations. This averaging yields what look like broad but slow, oppositely-moving ( ~ 5 m s-1) bands lying to either side of the centroid of the sunspot butterfly, making the activity band appear to be a zone of weakly enhanced shear. In most discussions, the pattern has been characterized as axially symmetric, but such longitudinal averages could equally well arise from a system of large-scale vortices associated with the active regions, if such vortices rotated counterclockwise in the Northern hemisphere and clockwise in the Southern hemisphere. For some time Doppler charts made from the Mount Wilson data, though noisy, have indicated that the torsional pattern is not axially symmetric, at least during the active phase of the cycle; and recent maps of local velocities determined from short-term tracer tracking at Big Bear Solar Observatory suggest that there are large vortical motions superposed on the mean differential rotation. In any case, it is evident that the torsional pattern tells us something about the cycle, and since it precedes the onset of activity, it might be useful as a predictor of the level of activity to come. For the present cycle 23, the torsional pattern did not emerge until just before solar minimum, whereas for cycles 21 and 22 it appeared several years earlier. This would have suggested by 1996 that that the present cycle would be weaker than the previous two (as it apparently is), while other predictors as late as 1998 forecasted a very strong cycle. This work is supported through NSF Grant ATM98-14145.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Torsional Oscillations: Vorticity; Solar Cycle Predictions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Torsional Oscillations: Vorticity; Solar Cycle Predictions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Torsional Oscillations: Vorticity; Solar Cycle Predictions will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1270734

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.