John wrote:

>2) I’ve been reluctant to embrace Nadja Kutz’s theory that an exact biannual cycle in the Earth’s temperature could arise from a resonance of the magnetic fields of Earth and Sun.


I never called this a "theory", but it is just one possibility of a couple of working hypothesis. Like I had also mentioned a couple of times here (see e.g. here) that eventually e.g. a different radiation balance of the two hemispheres could
play a role that was actually my first hypothesis and the reason why I had started to check the insolation formula. (I think I had commented on that change of the formula here on the forum too, but I currently can't find the comment).