Abstract:
We examine long spectral time series of polar coronal holes with the Coronal Diagnostics Spectrometer (CDS) on-board SoHO. Previously, the presence of long period waves in the plumes and inter-plume regions has been reported from the observations of transition region lines. From the current study of several coronal lines we will report on the presence of long period outwardly propagating slow magneto-acoustic waves in several locations. We will also try to search for the origin of these waves and will report on the connections, if any, of networks bound-arise in the disk part of the coronal holes and the plume and inter-plumes. These slow magneto-acoustic waves may contributed significantly to the heating of the lower corona by compressive dissipation may also provide some of the energy flux required for the acceleration of the fast solar wind.