Jet 4: 2011 February 16 – Left panel: AIA 171 Å image of the jet observed on 2011 February 16. The recurrent jet appeared to evolve from the eastern edge of the active region, 11158 (S20 W41), which was associated with a negative-polarity sunspot. A small-scale brightening was observed at 13:32 UT at the jet footpoint before the jet evolution, and the jet evolved as a complex, multi-threaded spire. The observations show the continuous untwisting motion of the jet spire with radial motion. The jet started its activity at 13:24 UT, and lasted until 13:42 UT. Middle panel and right panel: the LOS HMI magnetogram image at 12:28 UT, before the jet evolution and at 13:40 UT, during the jet evolution, respectively. The positive flux emergence and cancellation was observed near the negative-polarity sunspot region shown by white arrows. This magnetic activity lasted for a few hours and was co-temporal and co-spatial with the jet activity.