User:Shelby Crisp/Dungey Cycle

Dungey Cycle
The Dungey cycle, officially proposed by James Dungey in 1961, is a phenomenon that explains interactions between a planet's magnetosphere and solar wind. Dungey originally proposed a cyclic behavior of magnetic reconnection between Earth's magnetosphere and flux of solar wind. This reconnection explained previously observed dynamics within Earth's magnetosphere. The rate of reconnection in the beginning of the cycle is dependent on the orientation of the interplanetary magnetic field, hereafter referred to as IMF as well as the resultant plasma conditions at the site of reconnection. On earth, the reconnection cycle takes around 1 hour, but this changes from planet to planet.

Cyclic Behavior
The cycle itself occurs within three stages. The first being a reconnection between solar flux and the magnetopause. This creates an opening in the magnetopause in which the solar wind can enter the magnetosphere. This opening is called the dayside reconnection, It occurs on the side of the magnetosphere facing the solar wind source. In the second stage, the flux travels in the direction of the solar wind across the magnetosphere. The third stage occurs at the magnetotail. The eventual reconnection at the tail end will close the open flux, which allows for a new cycle to begin. This reconnection is called nightside reconnection. Dungey's proposal originally put forth an explanation that the cycle is steady state, and that the reconnection during stage one and three are equal. However, later work has found that the rate of reconnection is variable, and affected by conditions at both the dayside reconnection site as well as the magnetotail.

Effect of IMF orientation
The rate of reconnection at the magnetopause is heavily dependent on the orientation of the IMF. Reconnection at the magnetopause occurs at higher rates when the orientation of the IMF has a stronger southward component to the field. This allows for solar wind with arbitrarily small shear angles to reconnect at the magnetopause. Under normal circumstances, the difference in field strength between the magnetopause and the fields that surround it only allow for solar winds with large shear angles to reconnect. An orientation of the IMF with a strong southward component normalizes the difference in field strength between the magnetopause and surrounding fields.

Rough Draft
The Dungey cycle, officially proposed by James Dungey in 1961, is a phenomenon that explains interactions between the Earth's magnetosphere and solar wind.

The Dungey cycle describes the interconnection of energy from solar winds and the interplanetary magnetic field associated with those winds, and the Earth's magnetic field. It occurs when solar winds interact with the ionosphere. In this interaction, two neutral points are formed on either side of Earth. Symmetrical planes of potential form and wrap around the Earth. The concept of magnetic reconnection refers to sheared magnetic field lines threading the magnetic sheet separating them. ....[need more here to describe the full cycle -- be sure to include magnetopause and magnetotail].