Figure 7From: Filtering ionosphere parameters to detect trends linked to anthropogenic effectsfoF2 trend estimated for the 1960 to 1980 period. foF2 trend (MHz/year) estimated for periods beginning in 1960 for (a) Slough and (b) Juliusruh. Trend values are assigned to the last year of the period of trend estimation. The 95% confidence level (dashed lines) using Rz (black line) and F10.7 (red line) as solar EUV radiation proxies is shown.Back to article page