THE SENSITIVITY OF CHROMOSPHERICALLY INDUCED P-MODE AND F-MODE FREQUENCY-SHIFTS TO THE HEIGHT OF THE MAGNETIC CANOPY

Previous investigations of the effect of a magnetic canopy on the solar p- and f-modes are extended to allow for variations in height of the magnetic canopy. Analytical solutions in the limit of long horizontal wavelength are obtained and exhibit explicitly the dependence of frequency shifts on magnetic field strength, wavenumber, and canopy height. Frequency shifts are principally due to changes in canopy height. Full numerical solutions are also presented. It is argued that changes in chromospheric magnetism will be manifest in p- and f-mode data sets gathered at different phases of the solar cycle. A comparison of our theoretical results with the recent data obtained by Libbrecht and Woodard is made.