Supplementary material from "Indications for solar influence on radon and thoron in the atmosphere, Arad, Romania"

Radon (Rn-222; Rn) and Thoron (Rn-220; Tn) from the lowermost atmosphere in Arad, Romania, are investigated from 1993 to 2015. Daytime and night-time measurements exhibit: (a) systematic differences; (b) large annual variations; (c) semiannual and possibly ternary annual periodicities; (d) amplitudes of the annual and semi-annual periodicities differ among daytime and night-time measurements. The day-of-year of the summer-peak-time (SPT) of the annual variation of composite Rn and Tn data depict smoothly covarying SPT patterns separated around 50 days. SPT patterns of daytime and nighttime of Rn and Tn depict additional separations of gradually varying multi-year patterns. For both radionuclides, the night-time SPT precedes the daytime SPT—by around 105 days for Tn and around 60 days for Rn. In the case of temperature, the SPT of daytime and night-time measurements overlap at around Day 195. Thus, for Rn and Tn, daytime and night-time differences depend on the time of measurement within the 24 h cycle. This implies that Rn and Tn measurements are influenced by the rotation of the Earth around its axis. It is suggested that these relations, observed in coexisting Rn and Tn, are a further indication for a solar (extraterrestrial) influence on nuclear radiation, previously suggested for radon.