F.7 Activity indices information

Figure F-2 and Figure F-3 show the F10.7, Sunspot Number R and A_p indices over the last two solar cycles. Figure F-2 gives the daily and Figure F-3 the monthly mean values. The large fluctuations in the daily values are averaged out in the monthly mean values (please note the different scale of the figures). The short term A_p spikes are important for density variations and this is not well reflected in the long term high values.