Solar Activity Indices in 21, 22 and 23 Cycles

摘要

The monthly average values of the main solar activity indices such as Wolfnumbers (W), 10,7 cm radio flux (F10,7), 0,1-0,8 nm background, total solarirradiance and Mg II UV-index (280 nm core to wing ratio) were studied for 23activity cycle. The correlation coefficients of linear regression for mainsolar activity indices versus F10,7 were analyzed for every year of 23 activitycycle. All the correlation coefficients for 23 activity cycle have the minimumvalues in 2001. We also analyzed the connection between monthly average valuesof the most popular indices W and F10,7 for 21, 22 and 23 solar activitycycles. The values of every year linear regression correlation coefficients forW versus F10,7 show the cyclic variations with period closed to half path ofso-called 11-year period of solar activity.