As planetary magnetic fields reverse their polarity at times, the orientation of the Earths magnetic field at the time is not the way it has been oriented at all times.
Mars magnetic field is currently aligned in the opposite direction of Earths’, and similar how the Earths’ magnetic field was oriented before the latest magnetic reversal about 12000 years ago, and it aligns in direction with the suns incoming field that goes in through the north pole and out through the south pole, with a net downward field at the north pole, forcing water into a solid form.
So, about 12000 years ago, when the south pole was the positive pole of Earth, the incoming magnetic field from the sun did not align with that of the Earths’ magnetic field at the south pole, and did not lower the freezing point of water, so the continent of Antarctica was not in an “ice age”, as it is today.
