Chatzistergos, Theodosios; Ermolli, Ilaria; Krivova, Natalie A; Solanki, Sami K; Banerjee, D; Barata, Teresa; Belik, Marcel; Gafeira, Ricardo; Garcia, Adriana; Hanaoka, Yoichiro; Manjunath, H; Klimes, Jan; Korokhin, Viktor V; Lourenço, Ana; Malherbe, Jean-Marie; Marchenko, Gennady P; Peixinho, Nuno; Sakurai, Takashi; Tlatov, Andrey G
(EDP Sciences, 2020-07)
Context. Studies of long-term solar activity and variability require knowledge of the past evolution of the solar surface magnetism. The archives of full-disc Ca II K observations that have been performed more or less ...