Magnetopause reconnection and indents induced by foreshock turbulence

TL;DR

This study uses global hybrid simulations to demonstrate that foreshock turbulence can reach the magnetopause, induce magnetic reconnection, and create Earth-sized indents, potentially affecting planetary plasma loss.

Contribution

It reveals that foreshock turbulence alone can generate magnetopause reconnection and indents without changes in the interplanetary magnetic field or solar wind conditions.

Findings

Foreshock turbulence can reach the magnetopause in simulations.

Turbulence induces large magnetic shear angles leading to reconnection.

Magnetopause indents from turbulence may influence plasma loss.

Abstract

Based on global hybrid simulation results, we predict that foreshock turbulence can reach the magnetopause and lead to reconnection as well as Earth-sized indents. Both the interplanetary magnetic field (IMF) and solar wind are constant in our simulation, and hence all dynamics are generated by foreshock instabilities. The IMF in the simulation is mostly Sun-Earth aligned with a weak northward and zero dawn-dusk component, such that subsolar magnetopause reconnection is not expected without foreshock turbulence modifying the magnetosheath fields. We show a reconnection example to illustrate that the turbulence can create large magnetic shear angles across the magnetopause to induce local bursty reconnection. Magnetopause reconnection and indents developed from the impact of foreshock turbulence can potentially contribute to dayside loss of planetary plasmas.