The Solar Activity during the Holocene: Amplitude Variations of the Quasy-century and Quasi-two-century Solar Cycles

摘要

We summarize the recent results and prospective work in two parallel studies (Komitov; Bonev, Penev and Sello) of the long-term trends in solar variability that can be deduced from both indirect data and optical records. Analysis of data from lAC measurements (Stuiver et al 1998), aurorae (Schove series: Shove 1983), and direct astronomical records (group sunspot number) (Hoyt & Schatten 1998) focus on the stability and changes in amplitude of the cycles with duration near one and two centuries. Although these two projects have been carried independently and different methods have been used. We present them in a joint fashion in order to emphasize the common direction of their work.