3D magnetic configuration constructed with the NLFFF model. Panels a and b exhibit the top and side views of a few typical field lines, respectively. Panel c presents the corresponding zoom-in view and the bottom Q distribution. The cyan and orange field lines might reconnect and lead to the longer pink field lines above and to the short green loops below. The long yellow lines are active region magnetic field lines. Panels d and e exhibit the 1400 Å and Hα –0.8 Å images at 18:32 UT observed by the IRIS and GST, respectively. The yellow vertical line in panel d represents the IRIS slit, and the inset shows the spectra of Si IV 1403 Å. Panel f shows the reconnection configuration and the distributions of the squashing degree Q.