THE LOCATION OF THE SOURCE OF HIGH-FREQUENCY SOLAR ACOUSTIC-OSCILLATIONS

Recently Libbrecht and Jefferies et al. have reported regular peaks in the solar oscillation power spectrum extending well above 5.3 mHz, the maximum frequency of trapped acoustic modes. Kumar et al. argued that these peaks are primarily due to the interference of traveling waves which are excited due to acoustic emission from turbulent convection. In contrast with the standing wave P-mode frequencies below 5.3 mHz, the positions of the high-frequency interference peaks (HIPs) are dependent on the location of the source of the acoustic oscillations. In this Letter we strengthen Kumar et al.'s argument, and more importantly we make use of the above dependence to determine the acoustic source strength as a function of depth. We find that the acoustic source profile, and thus the convective velocity, is peaked approximately 200 km deeper than what is expected from standard mixing length theory.