SOURCES OF QUASI-PERIODIC PROPAGATING DISTURBANCES ABOVE A SOLAR POLAR CORONAL HOLE

Quasi-periodic propagating disturbances (PDs) are ubiquitous in polar coronal holes on the Sun. It remains unclear as to what generates PDs. In this work, we investigate how the PDs are generated in the solar atmosphere by analyzing a four-hour data set taken by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We find convincing evidence that spicular activities in the solar transition region, as seen in the AIA 304 angstrom passband, are responsible for PDs in the corona as revealed in the AIA 171 angstrom images. We conclude that spicules are an important source that triggers coronal PDs.