Revised Sunspot Data

Credits

Kindly note that all the sunspot data used in my own calculations were downloaded from (SILSO data/image, Royal Observatory of Belgium, Brussels). 

New way to check and report sunspot data implemented

The Royal Observatory of Belgium changed over to a new way to capture and report sunspot number on 1 July 2015. The Press release is linked for your convenience.

On the website of the  Royal Observatory of Belgium there are links to the reports and papers published by the work groups that  that led to this change. Take some time to read the reasons for the change. There are numerous reasons for the changes, but in the end it all boils down to one element, the humans and their errors that captured and will continue to capture the sunspot data.

Reasons for change

It is not my intention to list all the reasons  - strong and valid as they are - for the changes, but the following important ones caught my eye:

1. Change in instrumentation. Well it is pretty obvious that if you use a stronger telescope - with its appropriate adjustments, you will not just point your telescope to look at the sun will you? -- you will see more detail and more sunspots.
2. Change in eyesight of observer. This I found very sad and painful to read.  Image the poor dedicated man who recorded the sunspot numbers for more than 30 years with an ever failing sight, counting less and less sunspots as time goes by. I have great admiration for him and can only applaud the work group, led at times by Lief Svalgaard, for the sympathetic way they described this issue. 

My findings

I downloaded the revised sunspot series at the beginning of August 2015 and plotted the new sunspot series against the data from the old sunspot series using the LOESS - as described previously - function in Excel. The same Y-axis maximum of 350 sunspots is used in all the graphs I prepared to make it easier to compare.

Conclusion

The big difference between the earlier sunspot data and the most recent sunspot cycles have disappeared. We cannot talk of the 20th Century super cycles anymore.