Relation between the mode of oscillation and the velocity amplitude of chromospheric waves

The distribution of oscillation-amplitude for Doppler shifts in chromospheric lines is computed as a function of position on the disk and time frequency. High amplitude regions are restricted to a small part of the solar surface. Propagation modes are investigated with respect to the oscillation amplitude in the K line. Waves seem to be standing or evanescent for most of the points (small amplitude in K) and progressive for some other ones, with perhaps upward and downward motions (partial reflections). Mechanical energy could only escape into corona from narrow chromospheric structures.