While that argument might work in the southern hemisphere, the correct reason is, of course, the tilt of the earth's rotation axis relative to the oribital plane.
(that argument; might work; L:in the southern hemisphere) (the correct reason; is; the tilt of the earth's rotation axis relative to the oribital plane)
that argument the correct reason
might work is
L:in the southern hemisphere
the tilt of the earth's rotation axis relative to the oribital plane