In one of his EU lectures Dr. Gerald Pollak makes the suggestion that the atmospheric jet stream of our planet may be an important contributor to its magnetic filed.
The jet stream is a persistent high velocity wind, high in our atmosphere, that moves from west to east.
With the ionosphere being negatively charged relative to Earth, we can assume the jet stream to be negatively charged as well.
That corresponds to an electric current going from east to west.
Using Ampere’s right hand grip rule, we can now hold our right hand out with our thumb pointing left to determine the direction of the magnetic field going through our planet.
Jet stream generating a magnetic field
Our fingers point down, so we have a magnetic field inside our planet that has its north seeking pole to the south, exactly as we would expect.
A compass left free to move in the external magnetic field of our planet will point north with its north seeking pole.