Uncertainties in the Sunspot Numbers: Estimation and Implications

Abstract

Sunspot number series are subject to various uncertainties, which are still poorly known. The need for their better understanding was recently highlighted by the major makeover of the international Sunspot Number [Clette et al., Space Science Reviews, 2014]. We present the first thorough estimation of these uncertainties, which behave as Poisson-like random variables with a multiplicative coefficient that is time- and observatory-dependent. We provide a simple expression for these uncertainties, and reveal how their evolution in time coincides with changes in the observations, and processing of the data. Knowing their value is essential for properly building composites out of multiple observations, and for preserving the stability of the composites in time.

accepted in Solar Physics (2016), 24 pages

References in corpus (5)

• Historical Sunspot Observations: A Review
• Methodology to create a new Total Solar Irradiance record: Making a composite out of multiple data records
• An Assessment of Sunspot Number Data Composites over 1845-2014
• A method for filling gaps in solar irradiance and in solar proxy data
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• Scale Transfer in 1849 : Heinrich Schwabe to Rudolf Wolf
• Reconstruction of the Sunspot Number Source Database and the 1947 Zurich Discontinuity
• Intensity contrast of solar network and faculae -- II. Implications for solar irradiance modelling
• Nonparametric monitoring of sunspot number observations: a case study