Speaker
Description
The International Sunspot Number (ISN) series, a cornerstone for space climate studies, still exhibits scale discrepancies despite recent recalibrations, underscoring the critical need for a comprehensive reconstruction from raw historical observations. The FARSuN (Findability and Accessibility of historical Raw Sunspot Numbers) project addresses this by systematically gathering, digitizing, and standardizing scattered sunspot data from 1607-1980, aiming to bridge the technical and scientific gap preventing holistic data use. Significant progress includes the digitization of Prof. Wolf's Mittheilungen (1610-1918) and the near-completion (95%) of more than 2000 Zürich observation tables, transforming them into machine-readable formats. Data extractions for challenging sources like Gruithuisen, Stark, Adams, and Rost are actively underway, supported by advanced tools like Transkribus and rigorous quality control efforts to define homogeneous metadata criteria. Upcoming initiatives include a citizen science web interface to engage the public in data recovery and the ultimate goal of constructing a new, consolidated ISN (V3) and historical hemispheric sunspot numbers. This comprehensive reconstruction will provide the Space Climate Community with an unprecedentedly accurate and accessible record, significantly improving solar cycle predictions, understanding long-term solar variability, space weather discussions, and refining climate models.
