Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth's Magnetosphere

TL;DR

This paper demonstrates that Magnetic Flux Transport analysis effectively identifies active magnetic reconnection sites in Earth's magnetosphere using in-situ spacecraft data, outperforming traditional plasma outflow methods.

Contribution

The study applies and validates the Magnetic Flux Transport technique on multiple in-situ events, showing its robustness and higher detection rate in complex plasma environments.

Findings

MFT identifies active reconnection with inward and outward flux flows at X-points.

MFT outperforms plasma outflow jets in detecting reconnection.

Applicable to single- and multi-spacecraft measurements.

Abstract

Magnetic reconnection plays an important role in converting energy while modifying field topology. This process takes place in varied plasma environments in which the transport of magnetic flux is intrinsic. Identifying active magnetic reconnection sites in in-situ observations is challenging. A new technique, Magnetic Flux Transport (MFT) analysis, has been developed recently and proven in numerical simulation for identifying active reconnection efficiently and accurately. In this study, we examine the MFT process in 37 previously reported electron diffusion region (EDR)/reconnection-line crossing events at the dayside magnetopause and in the magnetotail and turbulent magnetosheath using Magnetospheric Multiscale measurements. The coexisting inward and outward MFT flows at an X-point provides a signature that magnetic field lines become disconnected and reconnected. The application of MFT analysis to in-situ observations demonstrates that MFT can successfully identify active reconnection sites under complex varied conditions, including asymmetric and turbulent upstream conditions. It also provides a higher rate of identification than plasma outflow jets alone. MFT can be applied to in situ measurements from both single- and multi-spacecraft missions and laboratory experiments.