HEIGHT DEPENDENCE OF THE AMPLITUDES OF SOLAR OSCILLATIONS VIEWED WITHA POTASSIUM RESONANCE SCATTERING SPECTROMETER

Over the course of the year, the variation in the solar line-of-sight velocity causes a change in the heights in the photosphere which are a nalysed by the red and blue passbands of a resonance scattering spectr ometer. This in turn would be expected to produce a variation in the r atio of acoustic amplitudes measured in each passband. Using data from the Tenerife spectrometer of the Birmingham Solar Oscillations Networ k (BiSON), we demonstrate such a seasonal change. We then use the Eddi ngton-Barbier approximation and an atmospheric model to convert the ma gnitude of this trend in velocity ratio with line-of-sight velocity in to an approximate value of 580 km for the velocity-amplitude scale hei ght. However, a simple argument suggests that 'Doppler imaging' causes this to be an overestimate of the true value.