Plasmoid-dominated Turbulent Reconnection in a Low- β Plasma

Properties of plasmoid-dominated turbulent reconnection in a low-β background plasma are investigated by resistive magnetohydrodynamic (MHD) simulations. In the βin < 1 regime, where βin is plasma β in the inflow region, the reconnection site is dominated by shocks and shock-related structures and plasma compression is significant. The effective reconnection rate increases from 0.01 to 0.02 as βin decreases. We hypothesize that plasma compression allows a faster reconnection rate, and then we estimate a speed-up factor, based on a compressible MHD theory. We validate our prediction by a series of MHD simulations. These results suggest that the plasmoid-dominated reconnection can be twice as fast as expected in the β ≪ 1 environment in a solar corona.