Solar Physics, vol. 60, Nov. 1978, p. 181-201. Deutsche Forschungsgemeinschaft
Schroeter, E. H.; Woehl, H.; Soltau, D.; Vazquez, M.
Results of almost simultaneous observations of the differential rotation of the Ca(plus) chromosphere and the photospheric plasma are reported. The observations (tracings of Ca(plus) mottles and Doppler shift measurements in a photospheric line) were performed at the Locarno station during two extended periods in 1976. Both data sets were used to search for a large scale circulation pattern. A regular long-lived pattern could not be detected, but a single cell with radial outflow (approximately 40 m/sec) extending over more than 50 deg in longitude has been found. Statistically significant temporal changes of the differential rotation law of the Ca(plus) chromosphere correlated with changes of meridional motions, and differences in the rotation of the two hemispheres were observed.