World Data Center for the production, preservation and dissemination of the international sunspot number


Sunspot number series: latest update

Daily estimated sunspot number
16 April : 12
17 April : 16
18 April : 26
19 April : 24
20 April : 12

New prediction method

Starting from a collaboration with the NCEI (NOAA, Boulder USA), we implemented new 12-month ahead predictions based on the McNish and Lincoln method. This rather simple method is based on a single mean cycle profile and is thus of "climatology" type. It was used as a standard for many years at NOAA, and we now add it to our other more advanced Standard Curves and Combined methods, allowing direct comparisons. Likewise, we now also provide a Kalman-filter optimized version of these new ML predictions.
On this occasion, we slightly modified our data section: graphics and predictions can now be found in the new "Products" section, which gathers all data products derived from our primary sunspot number series, including our monthly sunspot bulletins.

Fri, 24 Mar 2017
Latest USET observations (ROB, Brussels) 20/04/2019

Latest USET drawing

Latest USET image
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