Soderblom: You showed some pre-Maunder Minimum cycles. Are they in phase with the ones after the Maunder Minimum?
White: They tend to be, yes. If you look at the Beryllium 10 record, it looks like things stay in phase.
Harvey: And that would argue that cycles were in fact going on, through the Maunder Minimum phase.
Soderblom:But you just can't tell, because it was too subtle?
Harvey: You can't really tell from the numbers, but the spatial distribution gives us clues that it was in fact going on.
White: The Beryllium 10 record is very clear about an 11-year periodicity going on, right through the Maunder Minimum. So you know something was going on with the coronal activity, modulating the cosmic rays that produce Beryllium 10.
Harvey: There's even some work being done with geomagnetic activity during this period, using aurorae and such, and those workers also find that the 11-year periodicity was still there. It is at a much, much lower level, consistent with the lower sunspot number.