Substorms and Solar Eclipses: Coincidence?

Geomagnetic substorms are typically described in terms of solar wind-magnetosphere coupling, with little regard to how ionospheric conditions mediate their occurrence. However, recent case studies on the geomagnetic response to solar eclipses have led to questions about the ionospheric contribution to substorm development. We present in this study a mutual information analysis that investigates the coincidence of substorms during eclipses, and try to explain why these phenomena are coincident more often than would be expected by random chance.