Geomagnetic Substorms and Solar Eclipses: A Mutual Information Analysis

Geomagnetic substorms have been studied since the early 1900s, but remain a topic of intense discussion and debate. Much of the work relating to substorm onset focuses on the well proven magnetospheric drivers of substorms, but no single model is sufficient to describe all occurrences. Recently, a body of work has emerged investigating the impacts of ionospheric conductivity on the occurrence rate and magnitude of substorms. The ionosphere varies regularly between the hemispheres due to the seasonal tilting of Earth's rotational axis, but during a solar eclipse these conductivity variations occur much more rapidly and without a regular seasonal dependence. Coincidentally, it is observed that substorms regularly occur during solar eclipses. By investigating substorm occurrence during these periods of dramatic ionospheric conductivity variations, we may be able to provide greater insight into how ionospheric conductivity impacts coupling between the Solar Wind-Magnetosphere-Ionosphere system.