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Solar activity and oscillation frequency splittingsSolar p-mode frequency splittings, parameterized by the coefficients through order N = 12 of a Legendre polynomial expansion of the mode frequencies as a function of m/L, were obtained from an analysis of helioseismology data taken at Big Bear Solar Observatory during the 4 years 1986 and 1988-1990 (approximately solar minimum to maximum). Inversion of the even-index splitting coefficients confirms that there is a significant contribution to the frequency splittings originating near the solar poles. The strength of the polar contribution is anti correlated with the overall level or solar activity in the active latitudes, suggesting a relation to polar faculae. From an analysis of the odd-index splitting coefficients we infer an uppor limit to changes in the solar equatorial near-surface rotatinal velocity of less than 1.9 m/s (3 sigma limit) between solar minimum and maximum.
Document ID
19930037627
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Woodard, M. F.
(NASA Headquarters Washington, DC United States)
Libbrecht, K. G.
(Big Bear Solar Observatory Pasadena, CA, United States)
Date Acquired
August 16, 2013
Publication Date
January 10, 1993
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 402
Issue: 2
ISSN: 0004-637X
Subject Category
Solar Physics
Accession Number
93A21624
Distribution Limits
Public
Copyright
Other

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