On the Variability of the Solar Integral Radiation Constituents

The results of spectral analysis of series of observations of the equatorial and polar diameters, as well as of series of satellite observations of the S sub O variations during 1975 to 1987 presented in papers by Laclare (1987), Delache (1988) and Delache et al. (1988) confirm with confidence the presence of an 11-year modulation in the Sun's radiation and diameter, and consequently, in the effective temperature of the photosphere. The same conclusion has been drawn with regard to the 1000th and 320th daily periodicities. In combination with the results of other research, several obvious conclusions can be drawn from the data presented. The 76-year variation in the period from 1967 to 1987 is not revealed in the data of observations; the data of the middle series will doubtless be made more precise after the facsimile from the initial information is obtained. The basic and comparable contributions to the radius variability yield the 11- and 22-year variations. The presence can easily be seen of harmonics with periods of 2 and 4 years; the 4-year period is revealed up to 1979 only, and the 2-year one, after 1980 only. This is possibly due to the combined contribution of the 11- and 22-year variations (to be more precise, 10.8 and 21.2 years) forming a certain mean 16-year periodicity. In this case, the 4- and 2-year variations can be regarded as the 4th and 8th harmonics of such a mean variation. Measurements of the horizontal diameter made at Greenwich Observatory have not lost their significance for the analysis of phenomena on the Sun, since they contain data having precision characteristics conforming to the level of the latest ground-based diameter measurements.