OBSERVATIONS AND MODELING OF NORTH-SOUTH ASYMMETRIES USING A FLUX TRANSPORT DYNAMO
- Armagh Observatory, College Hill, Armagh City BT61 9DG (United Kingdom)
- Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India)
- High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307 (United States)
The peculiar behavior of solar cycle 23 and its prolonged minima has been one of the most studied problems over the past few years. In the present paper, we study the asymmetries in active region magnetic flux in the northern and southern hemispheres during the complete solar cycle 23 and the rising phase of solar cycle 24. During the declining phase of solar cycle 23, we find that the magnetic flux in the southern hemisphere is about 10 times stronger than that in the northern hemisphere; however, during the rising phase of cycle 24, this trend is reversed. The magnetic flux becomes about a factor of four stronger in the northern hemisphere than in the southern hemisphere. Additionally, we find that there was a significant delay (about five months) in change of the polarity in the southern hemisphere in comparison with the northern hemisphere. These results provide us with hints of how the toroidal fluxes have contributed to the solar dynamo during the prolonged minima in solar cycle 23 and in the rising phase of solar cycle 24. Using a solar flux-transport dynamo model, we demonstrate that persistently stronger sunspot cycles in one hemisphere could be caused by the effect of greater inflows into active region belts in that hemisphere. Observations indicate that greater inflows are associated with stronger activity. Some other change or difference in meridional circulation between hemispheres could cause the weaker hemisphere to become the stronger one.
- OSTI ID:
- 22364305
- Journal Information:
- Astrophysical Journal, Vol. 799, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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