Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-10-07
Astrophys.J.655:651-659,2007
Astronomy and Astrophysics
Astrophysics
11 pages, 7 figures. accepted by Astrophys.J
Scientific paper
10.1086/509866
Helioseismology has revealed many details of solar differential rotation and also its time variation, known as torsional oscillations. So far there is no generally accepted theoretical explanation for torsional oscillations, even though a close relation to the solar activity cycle is evident. On the theoretical side non-kinematic dynamo models (including the Lorentz force feedback on differential rotation) have been used to explain torsional oscillations. In this paper we use a slightly different approach by forcing torsional oscillations in a mean field differential rotation model. Our aim is not a fully self-consistent model but rather to point out a few general properties of torsional oscillations and their possible origin that are independent from a particular dynamo model. We find that the poleward propagating high latitude branch of the torsional oscillations can be explained as a response of the coupled differential rotation / meridional flow system to periodic forcing in mid-latitudes, of either mechanical (Lorentz force) or thermal nature. The speed of the poleward propagation sets constraints on the value of the turbulent viscosity in the solar convection zone to be less than 3x10^8 m^2/s. We also show that the equatorward propagating low latitude branch is very unlikely a consequence of mechanical forcing (Lorentz force) alone, but rather of thermal origin due to the Taylor-Proudman theorem.
No associations
LandOfFree
Origin of solar torsional oscillations 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 Origin of solar torsional oscillations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Origin of solar torsional oscillations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-489494