We present a continuous analysis of the background oscillations of the Earth. We processed five years of vertical recordings from the German Regional Seismic Network (GRSN) and estimated the directions of arrival (DOA) of the background Rayleigh waves in the frequency range between 5 and 8 mHz. We find clear seasonal variations in the direction of propagation and a striking rate of recurrence in these seasonal patterns. This seasonality provides evidence of an excitation of the background oscillations by large-scale atmospheric and/or oceanic processes which confirms previous studies.