PEAK PARAMETER SHIFTS FROM LARGE APERTURE RING DIAGRAM ANALYSIS

摘要

We study the peak parameters from large-aperture ring-diagram analysis of Global Oscillation Network Group (GONG) data. This gives access to higher-order and hence higher-frequency modes than the standard ring-diagram analysis. At and above the acoustic cut-off frequency, the sensitivity of mode frequency, amplitude and width to magnetic activity level changes rapidly as a function of frequency. We investigate these changes and relate them to previous studies of high-frequency modes at different degrees.