Turbulent magnetic reconnection in the solar wind

Abstract

Turbulent magnetic reconnection was observed in the magnetotail and the magnetopause. In turbulent magnetic reconnection, the diffusion region is filled with a number of filamentary currents primarily carried by the electrons and some flux ropes. These dynamic filamentary currents constitute a kind of three-dimensional network in the diffusion region and lead the reconnection into turbulence. The electrons are trapped and sufficiently accelerated inside such a complicated current network.According to the previous observations, magnetic reconnection generally displays a quasi-steady state in the solar wind, where the energy is dissipated via slow-mode shocks. It is elusive why the reconnection in the solar wind is quasi-steady. Here we present a direct observation of bursty and turbulent magnetic reconnection in the solar wind, with its associated exhausts bounded by a pair of slow-mode shocks. We infer that the plasma is more efficiently heated in the magnetic reconnection diffusion region than across the shocks and that the flow enhancement is much higher in the exhausts than in the area around the diffusion region. We detected 75 other, similar diffusion-region events in solar wind data between October 2017 and May 2019, suggesting that bursty reconnection in the solar wind is more common than previously thought and actively contributes to solar wind acceleration and heating.