On the large scale brightness fluctuations in the solar atmosphere

The October 1976 spectroscopic observations of the solar chromosphere with the great coronagraph of the Kislovodsk Station of the Pulkovo Observatory were analysed using the autocorrelation method. The autocorrelation function and the power spectrum were calculated. It was found that the brightness distribution in the chromosphere is essentially bimodal and has characteristic scales of 1.2 × 10⁴ km and 2.4 × 10⁴ km. The supergranulation (3.5 × 10⁴ km) in the brightness field was found to show up more faintly at all heights.