Figure 1

Time series of selected parameters. (a) Sunspot numbers in time, the number of the solar cycle is also indicated; (b) neutron count rate (Oulu, Finland); (c–f) tritium time series with spline average trends in four selected location (Kaitoke, New Zealand; Cuxhaven, Germany; Debrecen, Hungary; Râmnicu Vâlcea, Romania); (g–k) tritium spline trends in fourteen locations.