Oscillations of visible chromosphere boundary and regularity in position of spicule groups along the limb

A series of H-filtergrams, covering about 42 min, was studied in order to obtain quantitative data on the oscillations of the visible chromosphere boundary and on the regularity in position of spicule groups along the limb. The results obtained reveal the existence of relatively slow vertical oscillations (a background) superimposed with those of 5 min period. A horizontal dimension of a spicule group 4000 km; a change of the chromosphere height within the latter occurs practically synchronously. A good correlation of height changes for groups of 25000 km apart is observed.