Relations between the solar inertial motion, solar activity and geomagnetic index aa since the year 1844 Original Research Article

The series of geomagnetic index aa and the series of the sunspot numbers W have been processed in the three intervals related to the three different intervals of the solar inertial motion (SIM) due to the giant planets: 1844–1905, 1906–1956 and 1957–2005. In the second interval, the Sun moves along the stable trefoil orbit, where its motion along one motion loop (arc) lasts 10 years. The orbits of the Sun in the first and the third intervals are of disordered type and differ one to other. Power spectra of both the solar and the geomagnetic activity in the central interval show the dominant period of 10.1 year and their patterns are very similar. Dominant period of sunspot numbers (index aa) in the first interval is the period of 11.4 (11.3) years. In the third interval, the period of 10.7 (10.8) years was detected. The spectra for W and aa computed for the first and third interval significantly mutually differ. The best fitted line for the second (trefoil) interval of solar and also of geomagnetic index aa is the straight line, for the first (third) intervals it is polynomial of the second (third) order.