000005845 001__ 5845
000005845 005__ 20220922151042.0
000005845 0247_ $$2DOI$$a10.1007/s11207-021-01882-6
000005845 037__ $$aSCART-2022-0091
000005845 100__ $$aClette, Frédéric
000005845 245__ $$aReconstruction of the Sunspot Number Source Database and the 1947 Zurich Discontinuity
000005845 260__ $$c2021
000005845 520__ $$aThe recalibration of the sunspot number series, the primary long-term record of the solar cycle, requires the recovery of the entire collection of raw sunspot counts collected by the Zurich Observatory for the production of this index between 1849 and 1980. Here, we report about the major progresses accomplished recently in the construction of this global digital sunspot number database, and we derive global statistics of all the individual observers and professional observatories who provided sunspot data over more than 130 years. First, we can announce the full recovery of long-lost source-data tables covering the last 34 years between 1945 and 1979, and we describe the unique information available in those tables. We then also retrace the evolution of the core observing team in Zurich and of the auxiliary stations. In 1947, we find a major disruption in the composition of both the Zurich team and the international network of auxiliary stations. This sharp transition is unique in the history of the Zurich Observatory and coincides with the main scale-jump found in the original Zurich sunspot number series, the so-called “Waldmeier” jump. This adds key historical evidence explaining why methodological changes introduced progressively in the early 20th century could play a role precisely at that time. We conclude on the remaining steps needed to fully complete this new sunspot data resource.
000005845 594__ $$aNO
000005845 700__ $$aLefèvre, Laure
000005845 700__ $$aBechet, Sabrina
000005845 700__ $$aRamelli, Renzo
000005845 700__ $$aCagnotti, Marco
000005845 773__ $$n137$$pSolar Physics$$v296$$y2021
000005845 8560_ $$felodie.brahy@ksb-orb.be
000005845 85642 $$ahttps://link.springer.com/article/10.1007/s11207-021-01882-6
000005845 905__ $$apublished in
000005845 980__ $$aREFERD