Examining the Nature of Diamagnetic Current Composition in Earth’s Magnetopause

Abstract:

The magnetopause is supported by a relatively thin current layer balancing the pressures induced by solar plasma upon the Earth’s magnetosphere. This large-scale current sheet is known as the Chapman-Ferraro current and has been studied since the 1930s. While the large-scale mechanism of this current is well established, the smaller scale diamagnetic currents, driven by pressure gradients in this region, are not fully understood. This study aims to examine large numbers of dayside magnetopause current crossings using a database from NASA’s Magnetospheric Multiscale Mission, and to perform a statistical analysis of the relative contributions of the density gradient and the divergence of the plasma temperature tensor to the diamagnetic current. The prevalence of density-driven and temperature-driven gradients will be assessed as a function of upstream conditions and location along the magnetopause boundary. The results obtained will provide an improved understanding of the small-scale current structures embedded in the larger scale Chapman-Ferraro current and the physical factors that drive them.