Semiannual fluctuation depending on the polarity of the solar main magnetic dipole field

Abstract

We examined the recently found semiannual fluctuation in the Sun‐weather relations on a broader European region. The fluctuation means stronger solar effects on the weather in the spring and autumn periods than in summer or winter. The existence of this effect has been confirmed but only during the parallel orientations of the terrestrial and solar main magnetic dipole fields; this latter varies by a 22‐year period. The phenomenon probably contributes to the interconnection mechanisms between the solar and terrestrial magnetic fields and apparently, through a completely unknown mechanism, to certain tropospheric processes. Although the fluctuation is perceivable, it should be noted that the statistical evidence of the results is still far from striking, and the physical explanation is still missing.