RECONSTRUCTION OF THE ANNUAL VARIATION IN SOLAR RADIO FLUX AND THE CATANIA SUNSPOT AREA FROM TREE RING-INDEX TIME-SERIES

Four tree ring-index site chronologies, representing standardised annu al growth rates for spruce trees growing at high altitude sites in Col orado, have been employed as proxy data in a regression model for the annual variation of solar radio flux at 2800 MHz (F10.7) and the Catan ia sunspot area (A(C)). These dendrochronological time series all exhi bit significant power spectrum peaks at about 11 years and separately correlate with the annual values of R(Z), F10.7 and A(C), as solar act ivity indicators. The two models constructed give the cyclic variation of F10.7 and A(C) back to AD1673.