000005312 001__ 5312
000005312 005__ 20210301153231.0
000005312 0247_ $$2DOI$$a10.1017/S174392131900396X
000005312 037__ $$aSCART-2021-0074
000005312 100__ $$aClette, Frédéric
000005312 245__ $$aSunspot and Group Number: Recent advances from historical data 
000005312 260__ $$c2020
000005312 520__ $$aDue to its unique 400-year duration, the sunspot number is a central reference for understanding the long-term evolution of solar activity and its influence on the Earth environment and climate. Here, we outline current data recovery work. For the sunspot number, we find historical evidence of a disruption in the source observers occurring in 1947–48. For the sunpot group number, recent data confirm the clear southern predominance of sunspots during the Maunder Minimum, while the umbra-penumbra ratio is similar to other epochs. For the Dalton minimum, newly recovered historical observations confirm a higher activity level than in a true Grand Minimum.
000005312 594__ $$aSTCE
000005312 6531_ $$aSunspots
000005312 6531_ $$aSolar cycle
000005312 6531_ $$aHistorical data
000005312 700__ $$aVaquero, José M.
000005312 700__ $$aCruz Gallego, María
000005312 700__ $$aLefèvre, Laure
000005312 773__ $$c156-159$$nSymposium A30$$pProceedings of the IAU$$v14$$y2020
000005312 8560_ $$ffrederic.clette@observatoire.be
000005312 85642 $$ahttps://www.cambridge.org/core/journals/proceedings-of-the-international-astronomical-union/article/abs/sunspot-and-group-number-recent-advances-from-historical-data/F1412DB008831540E33661AFB5241D6A
000005312 905__ $$apublished in
000005312 980__ $$aNONREF