  We examine the solar-cycle variation of the power in the low-degree
helioseismic modes by looking at binned power spectra from 45 years of
observations with the Birmingham Solar Oscillations Network, which provides a
more robust estimate of the mode power than that obtained by peak fitting. The
solar-cycle variation of acoustic mode power in the five-minute band is clearly
seen. Unusually, even though Cycle 24 was substantially weaker in terms of
surface magnetic activity than Cycle 23, the reduction in mode power at solar
maximum is very similar for the two cycles, suggesting that the relationship
between mode power and magnetic activity is more complex than has previously
been thought. This is in contrast to the mode frequencies, which show a strong
correlation with activity with only subtle differences between in the response
across different solar cycles.
