Figure 1From: Effect of solar cycle 23 in foF2 trend estimationTrend values. foF2 trend [MHz/year] for (a) Slough and (b) Kokobunji, July 12 LT, assessed for experimental foF2 data (triangles). Also shown are modeled trends for SUPIM foF2 (empty circle) and IRI foF2 (filled circle). The period of each trend value begins in 1964 and ends in the year indicated by the abscissa.Back to article page