Plasmoid-mediated reconnection under different plasma-β conditions. The panels show snapshots of the current density, J, for three different models with different values of plasma-β according to values given in the plots. The snapshots for low and moderate β in panels a and b are taken around the time when the overall evolution of J_max reaches a maximum. The snapshot for high β in panel c represents the situation when the J_max reached stably high values (cf. Fig. 4a). See Sect. 3.3.