  Small-scale magnetic fields are thought to play an important role in the
heating of the outer solar atmosphere. By taking advantage of the unprecedented
high-spatial and temporal cadence of IMaX, the filter vector polarimeter on
board the Sunrise balloon-borne observatory, we study the transversal and
longitudinal velocity oscillations in small magnetic elements. The results of
this analysis are then compared to MHD simulations, showing excellent
agreement. We found buffeting-induced transverse oscillations with velocity
amplitudes of the order of 1-2 km/s, to be common along with longitudinal
oscillations with amplitudes 0.4 km/s. Moreover, we also found an interaction
between transverse oscillations and longitudinal velocity oscillations, showing
a +-90 degrees phase lag at the frequency at which they exhibit the maximum
coherence in the power spectrum. Our results are consistent with the
theoretical picture in which MHD longitudinal waves are excited inside small
magnetic elements as a response of the flux tube to the forcing action of the
granular flows.
