  Polar corona is often explored to find the energy source for the acceleration
of the fast solar wind. Earlier observations show omni-presence of
quasi-periodic disturbances, travelling outward, which is believed to be caused
by the ubiquitous presence of outward propagating waves. These waves, mostly of
compressional type, might provide the additional momentum and heat required for
the fast solar wind acceleration. It has been conjectured that these
disturbances are not due to waves but high speed plasma outflows, which are
difficult to distinguish using the current available techniques. With the
unprecedented high spatial and temporal resolution of AIA, we search for these
quasi-periodic disturbances in both plume and interplume regions of the polar
corona. We investigate their nature of propagation and search for a plausible
interpretation. We also aim to study their multi-thermal nature by using three
different coronal passbands of AIA. In almost all the locations chosen, in both
plume and interplume regions we find the presence of propagating quasi-periodic
disturbances, of periodicities ranging from 10-30 min. These are clearly seen
in two channels and in a few cases out to very large distances (~250 arcsec)
off-limb, almost to the edge of the AIA field of view. The propagation speeds
are in the range of 100-170 km/s. The average speeds are different for
different passbands and higher in interplume regions. Observed disturbances are
insensitive to changes in slit width. This indicates that a coherent mechanism
is involved. In addition, the observed propagation speed varies between the
different passpands, implying that these quasi-periodic intensity disturbances
are possibly due to magneto-acoustic waves. The propagation speeds in
interplume region are higher than in the plume region.
