Sketch of the magnetic field configuration in a FER based on the two-layer extrapolations. The “+” and “−” symbols represent positive and negative polarity on the solar surface, respectively. The gray area outlined by dashed lines represents the average formation height of the He I layer. An AFS connecting two pores (P1 and P2) of opposite polarity is represented by a black closed loop. Arrows indicate the upflows and downflows of plasma along an AFS as observed in the He triplet line. The asterisk indicates the plausible location of magnetic reconnection near a mixed-polarity region.