An in-depth discussion of the analysis presented here can be found in an up-coming paper (Chaplin et al., 1997).

In order to investigate the solar-cycle dependence of the low-degree p-mode frequencies, we have analysed eighteen 4-month frequency spectra generated from BiSON Doppler velocity residuals collected between 1991 January 01 and 1997 January 05. These data cover the falling phase of solar activity cycle 22. up to the cycle 22/23 boundary. Fig. 1(a) shows frequency shifts, averaged over two orders in n. up to ~ 3900 μHz - as derived from the analysis of the 4-month spectra - normalised to unit change in the 10.7-cm radio flux. The dashed line lying above the BiSON data is a fit to the BBSO 1989-minus-1986 frequency shifts, for 4 ≤ ℓ ≤ 140 (Libbrecht k Woodard. 1991). The dotted line passing through the data corresponds to the bestscaled fit of the BBSO data to the BiSON data - the best-fit requires the BBSO data to be scaled by 0.71 ± 0.03. This is reasonably consistent - as expected - with the mean, overall ratio of the inverse mode masses of those data used in the BiSON and BBSO analyses (≈ 0.67). Fig. 1(b) shows the BiSON activity-normalised frequency shifts, plotted as a function of inverse mode mass - here, as anticipated, there is a clear correlation between the variables.