Transition to the new Sunspot Number successfully completed

  • Posted on: 1 July 2015
  • By: Admin

Today marked a triple transition for us:
- Uploading the new Sunspot Number archive files containing the daily, monthly and yearly re-calibrated sunspot numbers and the new Group Number series
- In our Web site, switching to the new "Data" pages giving access to the new files, to updated graphics and also to the past version of the Sunspot Number
- Adapting and running the entire monthly procedure to produce the provisional Sunspot Numbers for June 2015 and the associated 12-months forecast and EISN.
Thus a lot of work in a single day for our small team.

After intensive verifications and some inevitable bugs, we have now successfully completed this transition. The new numbers for June seamlessly extend the recalibrated historical sunspot series. Except for the announced elimination of the 0.6 conventional factor, absolutely no tweaking of the data was done. We simply kept the Specola Observatory (Locarno) as pilot station but now using regular counts strictly using the Wolf definition of the sunspot number (while earlier Specola counts were weighted according to the spot size, which increased the values relative to the past historical series).

The critical work has now been done for the core data but this is just the starting point for progressive improvements, like the extension of the documentation about the current data set or like additional and better error estimates for the past data.
So, this is not the end of the story. This new improved version of the Sunspot Number is certainly open to future improvements and developments, now that its has emerged from a long lethargy.

So, stay tuned!

(And now, we go take some rest ...)