2016
Ref: SCART-2017-0009

The New Sunspot Number: Assembling All Corrections

Clette, Frédéric ; Lefevre, Laure


published in Solar Physics, 291 issue 9-10, pp. 2629-2651 (2016)

Abstract: Based on various diagnostics and corrections established in the framework of several Sunspot Number Workshops and described by Clette et al. ( Space Sci. Rev. 186, 35, 2014), we now assembled all separately derived corrections to produce a new standard version of the reference sunspot-number time series. We explain here the three main corrections and the criteria used to choose a final optimal version of each correction factor or function, given the available information and published analyses. We then discuss the differences between the new corrected series and the original sunspot number, including the disappearance of any significant rising secular trend in the solar-cycle amplitudes after this recalibration. We also introduce the new version management scheme now implemented at the World Data Center Sunspot Index and Long-term Solar Observations (WDC-SILSO), which reflects a major conceptual transition: beyond the rescaled numbers, this first revision of the sunspot number also transforms the former static data archive into a living observational series open to future improvements.

Keyword(s): Sunspots ; statistics ; Solar cycle ; observations
Note: Sunspot Workshops Special Issue on the Sunspot Number
DOI: 10.1007/s11207-016-1014-y


The record appears in these collections:
Royal Observatory of Belgium > Solar Physics & Space Weather (SIDC)
Science Articles > Peer Reviewed Articles
Solar-Terrestrial Centre of Excellence



 Record created 2017-01-06, last modified 2017-01-06