Solar activity levels vs surface temperature variation

I posted the short comment below in reply to a blog post by Richard Telford

The first thing to do before making any stats tests is to consider how the physical mechanism may work. If the relatively high solar activity of the C20th did have an effect on temperature then it was by warming the oceans. Water has a high heat capacity, so Ocean Heat Content (OHC) (and thence SST) wouldn’t be expected to react instantaneously to solar variation. So we need to low pass filter or integrate solar data to mimic the thermal inertia of the oceans.