  The last solar minimum was, by recent standards, unusually deep and long. We
are now close to the maximum of the subsequent solar cycle, which is relatively
weak. In this article we make comparisons between different global (unresolved)
measures of the Sun's magnetic activity, to investigate how they are responding
to this weak-activity epoch. We focus on helioseismic data, which are sensitive
to conditions, including the characteristics of the magnetic field, in the
solar interior. Also considered are measures of the magnetic field in the
photosphere (sunspot number and sunspot area), the chromosphere and corona
(10.7cm radio flux and 530.3nm green coronal index), and two measures of the
Sun's magnetic activity closer to Earth (the interplanetary magnetic field and
the galactic cosmic-ray intensity). Scaled versions of the activity proxies
diverge from the helioseismic data around 2000, indicating a change in
relationship between the proxies. The degree of divergence varies from proxy to
proxy with sunspot area and 10.7cm flux showing only small deviations, while
sunspot number, coronal index, and the two interplanetary proxies show much
larger departures. In Cycle 24 the deviations in the solar proxies and the
helioseismic data decrease, raising the possibility that the deviations
observed in Cycle 23 are just symptomatic of a 22-year Hale cycle. However, the
deviations in the helioseismic data and the interplanetary proxies increase in
Cycle 24. Interestingly the divergence in the solar proxies and the
helioseismic data are not reflected in the shorter-term variations (often
referred to as quasi-biennial oscillations) observed on top of the dominant
11-year solar cycle. However, despite being highly correlated in Cycle 22, the
short-term variations in the interplanetary proxies show very little
correlation with the helioseismic data during Cycles 23 and 24.
