Scientists currently believe that the distorted shape of the Earth's Magnetic Field is caused by the "Solar Wind"  but little has been found to support this theory. The "Solar Wind" may well be nothing other than "Hot Air"

The atmospheric electric currents appear to be a self regulating "Force Field" in true science fiction fashion, with the triple purpose of shielding us, but not the oceans, from the  external gravitational pull of the Sun and the Moon, and also from the effects of variable centrifugal force, as well as creating some part of our planetary lighting.

1    Electric currents or field surrounding the Earth in ionosphere