THE HIGH-LATITUDE BRANCH OF THE SOLAR TORSIONAL OSCILLATION IN THE RISING PHASE OF CYCLE 24
- School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Ny Munkegade 120, Aarhus University, DK-8000 Aarhus C (Denmark)
- National Solar Observatory, P.O. Box 26732, Tucson, AZ 85726-6732 (United States)
- HEPL Solar Physics, 452 Lomita Mall, Stanford University, Stanford, CA 94305-4085 (United States)
We use global heliseismic data from the Global Oscillation Network Group, the Michelson Doppler Imager on board the Solar and Heliospheric Observatory, and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, to examine the behavior, during the rising phase of Solar Cycle 24, of the migrating zonal flow pattern known as the torsional oscillation. Although the high-latitude part of the pattern appears to be absent in the new cycle when the flows are derived by subtracting a mean across a full solar cycle, it can be seen if we subtract the mean over a shorter period in the rising phase of each cycle, and these two mean rotation profiles differ significantly at high latitudes. This indicates that the underlying high-latitude rotation has changed; we speculate that this is in response to weaker polar fields, as suggested by a recent model.
- OSTI ID:
- 22130734
- Journal Information:
- Astrophysical Journal Letters, Vol. 767, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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