Field lines from a pre-flare magnetic field reconstruction (11:00 UT) that are associated with the AIA 1600 Å flare ribbon enhancements during HXR peak 1. Panel 1a: all field lines with seed points within a positive polarity region. Panels 1b–1e: individual display of selected field lines. Panels 1f and 1g: Combined field lines shown from two different perspectives. Panels 2a–2g: same structure but for field lines with seed points in negative polarity regions. Panel 3a: an AIA 131 Å image taken during HXR peak 1. Panel 3b: combined structure of field lines with seed points selected from footpoints in both polarities.