MMS observations of explosive filamentary current within two adjacent ion scale flux ropes

Abstract

<p>Flux ropes have attracted extensive attention due to their importance in studying instantaneous magnetic reconnection over the past years. Recently, with the improvement of high spatio-temporal resolution measurements, kinetic-scale flux ropes have been detected. However, their generation and energy energization are still unclear. In this study, electron-scale filamentary currents within two adjacent ion scale flux ropes are observed using MMS data. We find that:</p><p>1. Intense and explosive filamentary currents in parallel and perpendicular directions are found inside the flux ropes.</p><p>2. The electron pitch angle distribution appears "X" like shape, and could be caused by the electron acceleration.</p><p>3. The filamentary current appears in the center of the "X" distribution.</p><p>The filamentary currents are important and are considered to be the evidence of secondary reconnection [Wang et al., 2020]. The observations in our study are important to reveal the particle acceleration and energy dissipation in magnetic reconnection.</p>