Enhanced Energy Conversion by Turbulence in Collisionless Magnetic Reconnection

Abstract

Magnetic reconnection and turbulence are two of the most significant mechanisms for energy dissipation in collisionless plasma. The role of turbulence in magnetic reconnection poses an outstanding problem in astrophysics and plasma physics. It is still unclear whether turbulence can modify the reconnection process by enhancing the reconnection rate or energy conversion rate. In this study, utilizing unprecedented high-resolution data obtained from the Magnetospheric Multiscale spacecraft, we provide direct evidence that turbulence plays a vital role in promoting energy conversion during reconnection. We reached this conclusion by comparing magnetotail reconnection events with similar inflow Alfvén speed and plasma β but varying amplitudes of turbulence. The disparity in energy conversion was attributed to the strength of turbulence. Stronger turbulence generates more coherent structures with smaller spatial scales, which are pivotal contributors to energy conversion during reconnection. However, we find that turbulence has negligible impact on particle heating, but it does affect the ion bulk kinetic energy in these two events. These findings significantly advance our understanding of the relationship between turbulence and reconnection in astrophysical plasmas.