DISCRETE HIGH-FREQUENCY p-MODES

摘要

Observations report that the p-mode frequencies change with the solar activity cycle. Over the frequency range 0 to 8.5 mHz, shifts can be either positive or negative, appearing to exhibit a wavelike behavior with downturn occurring at ～4.0 mHz and upturn at ～5.5 mHz. A simple polytrope convection zone model overlaid with an isothermal chromospheric atmosphere threaded by a uniform horizontal magnetic field demonstrates frequency shifts that are qualitatively similar to those observed for both high and low frequencies, with shifts being a consequence of simultaneous increases in chromospheric field strength and temperature.