The most prominent wave phenomena in the atmosphere above sunspots are the so-called umbral flashes and running penumbral waves. In chromospheric layers they appear as recurrent vigorous brightenings flashing in sunspot umbrae and excited waves propagating radially along penumbrae. Visually these phenomena resemble the effect of a stone falling into water.
A novel high-resolution, multi-layer study concentrating on the characteristics of running penumbral waves finally proves their photospheric origin. A very regular sunspot in NOAA 11823 was observed with the Interferometric BIdimensional Spectro-polarimeter (IBIS/DST) for one hour in various photospheric and chromospheric wavelength. The detailed analysis of wave power and propagation gives strong evidence for the scenario of running penumbral waves being upward propagating slow-mode waves guided by the field lines of the sunspot magnetic field and intimately coupled to the spectacular umbral flashes phenomena.