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Plumes are one of the most ubiquitous features seen at the limb in polarcoronal holes and are considered to be a source of high density plasma streamsto the fast solar wind. We analyze STEREO observations of plumes and aim toreinterpret and place observations with previous generations of EUV imagerswithin a new context that was recently developed from Hinode observations. Weexploit the higher signal-to-noise, spatial and temporal resolution of the EUVItelescopes over that of SOHO/EIT to study the temporal variation of polarplumes in high detail. We employ recently developed insight from imaging (andspectral) diagnostics of active region, plage, and quiet Sun plasmas toidentify the presence of apparent motions as high-speed upflows in magneticregions as opposed to previous interpretations of propagating waves. In almostall polar plumes observed at the limb in these STEREO sequences, in all coronalpassbands, we observe high speed jets of plasma traveling along the structureswith a mean velocity of 135km/s at a range of temperatures from 0.5-1.5MK. Thejets have an apparent brightness enhancement of ~5% above that of the plumesthey travel on and repeat quasi-periodically, with repeat-times ranging fromfive to twenty-five minutes. We also notice a very weak, fine scale, rapidlyevolving, but ubiquitous companion of the plumes that covers the entire coronalhole limb. The observed jets are remarkably similar in intensity enhancement,periodicity and velocity to those observed in other magnetic regions of thesolar atmosphere. They are multi-thermal in nature. We infer that the jetsobserved on the plumes are a source of heated mass to the fast solar wind.Further, based on the previous results that motivated this study, we suggestthat these jets originated in the upper chromosphere.

STEREO Observations of Quasi-Periodically Driven High Velocity Outflows in Polar Plumes