{"paper":{"title":"Analysis of full disc Ca II K spectroheliograms III. Plage area composite series covering 1892-2019","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.SR","authors_text":"Adriana Garcia, Ana Louren\\c{c}o, Andrey G. Tlatov, Dipankar Banerjee, Gennady P. Marchenko, Ilaria Ermolli, Jan Klime\\v{s}, Jean-Marie Malherbe, Manjunath Hegde, Marcel Belik, Natalie A. Krivova, Nuno Peixinho, Ricardo Gafeira, Sami K. Solanki, Takashi Sakurai, Teresa Barata, Theodosios Chatzistergos, Viktor V. Korokhin, Yoichiro Hanaoka","submitted_at":"2020-05-04T12:44:41Z","abstract_excerpt":"We derive the plage area evolution over the last 12 solar cycles employing data from all Ca II K archives available publicly in digital form known to us, including several as yet unexplored Ca II K archives. We analyse more than 290,000 full-disc Ca II K observations from 43 datasets spanning the period 1892-2019. All images were consistently processed with an automatic procedure that performs the photometric calibration (if needed) and the limb-darkening compensation. The processing also accounts for artefacts plaguing many of the images, including some very specific artefacts such as bright "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2005.01435","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2005.01435/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}