These cycles are described as the collective changes that take place due to the effects of the earth's movements on its climate which prevails over the thousand of years.
The earth's rotation on the axis and the revolution around the sun involve the gravitational attraction thus creates variation and complex cycles. So the distance between the earth's and the sun and the moon create s variation as seen by the seasons.
It is associated with the timing of the northern lights and the shift in the temperatures of the surface waters of the midlatitudes of the pacific ocean.