  High resolution movies in 193 A from the Atmospheric Imaging Assembly (AIA)
on the Solar Dynamic Observatory SDO show apparent rotation in the leg of a
prominence observed during a coordinated campaign. Such structures are commonly
referred to as tornadoes. Time-distance intensity diagrams of the AIA data show
the existence of oscillations suggesting that the structure is rotating.
  The aim of this paper is to understand if the cool plasma at chromospheric
temperatures inside the tornado is rotating around its central axis. The
tornado was also observed in Halpha with a cadence of 30 seconds by the MSDP
spectrograph, operating at the Solar Tower in Meudon. The MSDP provides
sequences of simultaneous spectra in a 2D field of view from which a cube of
Doppler velocity maps is retrieved.
  The Halpha Doppler maps show a pattern with alternatively blueshifted and
redshifted areas of 5 to 10 arcsec wide. Over time the blueshifted areas become
redshifted and vice versa, with a quasi-periodicity of 40 to 60 minutes. Weaker
amplitude oscillations with periods of 4 to 6 minutes are superimposed onto
these large period oscillations.
  The Doppler pattern observed in Halpha cannot be interpreted as rotation of
the cool plasma inside the tornado. The H$\alpha$ velocity observations give
strong constraints on the possible interpretations of the AIA tornado
