I agree.I was thinking about this. The latitude would primarily affect the magnitude of the driving term, right? That typically does not change the phase shift. Phase shift is usually determined by the resistance term and the frequency.
But I imagine the equator, which would see a spring, a fall, &
what could be seen as 2 winters. In my complete ignorance,
it just seems that this could alter the phase lag.
As you can see, I'm not approaching this rigorously.
It's all far above my pay grade.Although, because of tilt, there would be an extra piece on top of the sine wave forcing term. But a constant shift wouldn't affect the phase either.
Maybe a nonlinearity?
Back to the water issue, when bodies freeze, eg, the Great Lakes,
polar seas, weather & temperature change radically due to the
lower heat transfer rate of ice.
This would be a really interesting thing to investigate if I were
still a young buck with plenty of time on my hands, a more
nimble mind, & knowing my guzintahz.