THE DUNGEY CYCLE

The dancing lights are generated by invisible magnetic field lines that dance themselves

Magnetic field lines are highlighted in blue [1]. First they open up on the sunward side of Earth [2], then are dragged (with their plasma) over the poles [3] and laid down on the tail side of our planet [4]. Here they push down until magnetic reconnection closes the field lines once more [5] creating the aurora visible from Earth, after which [6] they migrate sideways back to the Sun side of the Earth [7]. This cycle can continue as long as the magnetic field of the solar wind is pointing southwards.

1 4 7 2 5 3 6 Solar wind flow Solar wind flow Solar wind flow Sun Sun Sun Interplanetary Magnetic Field (IMF) Solar wind flow Solar wind flow Solar wind flow Sun Sun Sun Sun Solar wind flow