Photospheric granulation may excite transverse kink pulses in anchored
vertical magnetic flux tubes. The pulses propagate upwards along the tubes with
the kink speed, while oscillating wakes are formed behind the wave front in a
stratified atmosphere. The wakes oscillate at the kink cut-off frequency of
stratified medium and gradually decay in time. When two or more consecutive
kink pulses with different polarizations propagate in the same thin tube, then
the wakes corresponding to different pulses may superimpose. The superposition
sets up helical motions of magnetic flux tubes in the photosphere/chromosphere
as seen by recent Hinode movies. The energy carried by the pulses is enough to
heat the solar chrmosphere/corona and accelerate the solar wind.Comment: Accepted in ApJ