Kinematic characteristics of the jets revealed by the IRIS observations. (a1)–(a3): sequence of 1400 Å images exhibiting the bright blob-like feature moving along the jet. The blue solid arrow in panel c denotes the ejecting direction of the bright blob. The dashed curve “Slice3” approximates the projected trajectory of bright blob. b1–b3: Corresponding 2796 Å images. (c1)–(c2): time-distance plots along the curve “Slice3” in 1400 Å and 2796 Å channels. The dotted oblique lines delineate linear fittings of projected trajectory of the bright blob in the rising phase. An animation (figure4.mov) of 1400 Å and 2796 Å channels, covering 00:40 UT to 01:51 UT, is available online.