On the 22-year oscillations

Observational data of the solar diameter in Italy during 1876-1937 and in Greenwich during 1851-1937 were analyzed. The Whittaker operator with different smoothing coefficients was used. The average data sets for the analysis of the possible oscillations of the solar diameter during 1876-1937 were obtained. Average values of the solar radius R(t) and absolute values of its time derivative \dR(t)/dt\ were compared with the Wolf number, W(t), and with the integral A(t) = integral(0)(t) W(t)dt + constant. A good correlation r(R', W) = [\dR(t)/dt\, W(t)] and r(R, A) = (R(t), A(t)) was found. It was shown that the frequency spectra of R(t) and A(t) are similar. It was found that during odd Il-yr cycles, the solar diameter decreases, whereas during even cycles it increases. A hysteresis-like behavior in the variation of R(t) during the 22-yr solar magnetic cycle was demonstrated.