the jet structure.

The helical shape and twisting have been further demonstrated by more advanced methods. Exploiting the stereoscopic capabilities of the joint observations by the two STEREO spacecrafts, @Patsourakos08 reconstructed a coronal jet in 3D and unambiguously revealed its helical shape. Doppler images have also been used to show that several coronal jet events presented strong rotational motions, blue- and red-shifts being observed on opposite sides of each jet [@Dere89; @Pike98; @Harrison01; @Jibben04; @Cheung15]. Combined spectroscopic and stereoscopic observations of a jet have been carried out by @Kamio10, who also recovered its helical structure and confirmed its rotating nature during the event.

Following the conceptual ideas of @Shibata85, @Shibata86, @Canfield96, and @Jibben04, in recent years several numerical works have suggested and shown evidence that [[helical jets]{}]{}were driven/accelerated at least partly due to propagating nonlinear Alfvénic waves [@Torok09; @Pariat09a; @Pariat10; @Pariat15a; @Lee15]. As discussed in Sect. 2 of @Pariat15a [hereafter PDD15], three main physical processes might explain the acceleration of the plasma: the [[tension-driven upflows]{}]{}that directly result from the local dynamics of the reconnected field line at the reconnection site; the [[evaporation upflows]{}]{}that are induced by the heat/pressure gradients in the reconnected field lines (heat created directly by the reconnection 