Detailed spectral analysis of Jupiterʹs Great Red Spot: relative intensities for the period 1963–1967

Maximum entropy analysis, the power spectrum (smoothed spectrum using the Blackman-Tukey window), Fourier spectral analysis and autocorrelation have been used to detect periodicities in the variation of Jupiterʹs Great Red Spot (GRS) relative intensities for the time period 1963–1967, referred to the 4300 (D43), 5500 (D55) and 6400 Å (D64) wavelengths. Periods ranging between 2 and 50 months have been obtained. Various tests of significance and stationarity of the obtained periods were applied to examine the reliability and variability of the periodic components. The results of these quasi-periodicities are discussed in relation to the solar wind and Jovian atmospheric features.