SOLAR-ACTIVITY AND OSCILLATION FREQUENCY SPLITTINGS

Solar 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 anticorrelated with the overall level of solar activity in the active latitudes, suggesting a relation to polar faculae. From an analysis of the odd-index splitting coefficients we infer an upper limit to changes in the solar equatorial near-surface rotational velocity of \DELTAupsilon(eq)BAR\ < 1.9 m s-1 (3 sigma limit) between solar minimum and maximum.