Filtering ionosphere parameters to detect trends linked to anthropogenic effects

Earth, Planets and Space

Table 2 foF2 trend values (MHz/year) estimated after filtering foF2 12-month running mean at 12 LT

Station	Lat.	Long.	foF2 trend (filtered with Rz) × 10^-3 MHz/year	foF2 trend (filtered with F10.7) × 10^-3 MHz/year
Slough	51.5°N	359.4°E	5 ± 2	-6 ± 1
Juliusruh	54.6°N	13.4°E	2 ± 2	-9 ± 2
Sodankyla	67.3°N	26.3°E	0 ± 2	-10 ± 2

Trend values were calculated with Rz (fourth column) and with F10.7 (fifth column) as solar EUV radiation proxies, for the 1960 to 2009 period. The error is estimated as twice the standard deviation.