SOLAR-PLANETARY CYCLES IN JUPITERS GREAT-RED-SPOT DARKNESS

The change in the darkness of the Great Red Spot (GRS) of Jupiter (189 4-1974) has been analysed with Fourier (FFT), Maximum Entropy and Powe r spectrum (Blackman-Tukey window) (PSA) methods of spectrum analysis. Significance, non-randomness and stationarity tests assigned high var iance to periodicities of 33 +/- 4, 13-15, about 11, 9 and 3 yrs. The highest correlation between solar activity and GRS darkness was found for the 14th and 16th solar cycle. The periodicities obtained are inte rpreted as the combined eftects of solar activity, planetary resonance s and internal jovian mechanisms.