For a geocentric axial dipole field, both the intensity and inclination (direction) of the geomagnetic field vary systematically with magnetic latitude: field intensity at the pole is twice that at the equator (B is proportional to sqrt(1+3sin^2(lat))), and the field direction is horizontal (parallel to Earth's surface, pointing toward the pole) at the equator but vertical (perpendicular to the surface) at the magnetic poles.