SHORT-PERIOD INSOLATION CHANGES CAUSED BY THE PLANETARY PERTURBATIONS OF THE EARTH'S ORBIT

M. B. Bogdanov

With the use of modern numerical methods of celestial mechanics the irradiance flux of the Sun incoming to the Earth is calculated under the assumption of the invariability of its luminosity in the time interval from 1700 through 2000. In the power spectrum of time series of insolation, together with the harmonics of the annual period of the Earth, clearly visible are the harmonics of the synodic periods of the planets of Venus, Mars, Jupiter, and Saturn and the harmonics that correspond to combination frequencies. The periods of these harmonics are located in the range from 100 days to 15.7 years. The main harmonics of the power spectrum are the harmonic that corresponds to the synodic period of Jupiter 399.0 days and the first harmonic of the synodic period of Venus with a period 291.9 days. The amplitudes of these harmonics are approximately equal and are about 40 mW/m2. It is interesting to attempt to find the manifestation of these harmonics in the power spectra of the meteorological time series.

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