  Coronal jets are believed to be the miniature version of large-scale solar
eruptions. In particular, the eruption of a mini-filament inside the base arch
is suggested to be the trigger and even driver of blowout jets. Here we propose
an alternative triggering mechanism, based on high-resolution H-alpha
observations of a blowout jet associated with a mini-filament and an M1.2-class
flare. The mini-filament remains largely stationary during the blowout jet,
except that it is straddled by flare loops connecting two flare ribbons,
indicating that the magnetic arcade embedding the mini-filament has been torn
into two parts, with the upper part escaping with the blowout jet. In the wake
of the flare, the southern end of the mini-filament fans out like neighboring
fibrils, indicative of mass and field exchanges between the mini-filament and
the fibrils. The blowout jet is preceded by a standard jet. With H-alpha
fibrils moving toward the single-strand spire in a sweeping fashion, the
standard jet transitions to the blowout jet. The similar pattern of
standard-to-blowout jet transition occurs in an earlier C-class flare before
the mini-filament forms. The spiraling morphology and sweeping direction of
these fibrils are suggestive of their footpoints being dragged by the leading
sunspot that undergoes clockwise rotation for over two days. Soon after the
sunspot rotation reaches a peak angular speed as fast as 10 deg/hr, the dormant
active region becomes flare-productive, and the mini-filament forms through the
interaction of moving magnetic features from the rotating sunspot with
satellite spots/pores. Hence, we suggest that the sunspot rotation plays a key
role in building up free energy for flares and jets and in triggering blowout
jets by inducing sweeping motions of fibrils.
