AN ALTERNATIVE EXPLANATION FOR THE OBSERVED VARIATION OF SOLAR P-MODES WITH THE SOLAR-CYCLE

By mimicking the effects of a magnetic field on the interior structure of a solar model, observed changes in p-mode frequencies over the cou rse of the solar cycle are explained in terms of a change in the inten sity and distribution of a magnetic field near the top of the solar co nvection zone; previous attempts of explain these observations have co ncentrated on magnetic fields extending into the solar atmosphere. Spe cifically, the observed frequency changes for the 5 less than or equal to l less than or equal to 60 modes between 1986 and 1989 can be acco unted for by a change in magnetic field strength of 400 G approximatel y 320 km below the solar surface; in a standard solar model, this dept h corresponds to a temperature of 10,800 K and a pressure of 3.63 x 10 (5) dyn cm(-2). These results are discussed in light of a measured cha nge in the solar radius of 4 km between 1992 and 1994 by the Solar Dis k Sextant Experiment.