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Sunspots 2013: Winter Solstice Surprise

Inform the Pundits blog

The monthly International Sunspot Number from the Solar Information Data Center (SIDC) of the Royal Observatory of Belgium was released January 1st, 2014.

In unexpected fashion, the sun closed out 2013 with a flurry of spots. It leaped up to 90.3 spots/day in December. That is the second highest daily sunspot average of any month so far this cycle. Only November of 2011 with 96.7 spots had more.

2013 was a very active year in an exceptionally weak sunspot cycle.

Though new research leans towards long-term solar cooling, the sun might have more surprises left in store for us this cycle.

Smoothed Sunspot Number Increases

This is a big deal!

The latest available smoothed sunspot number for June 2013 was reported this month by the SIDC, too. It jumped above 60 for the first time since early 2012. It is back up to 62.6.

What makes this a big deal is the largest smoothed monthly sunspot number defines the overall solar sunspot maximum for the cycle. Currently, the highest number is 66.5 in June of 2012.

Should sunspot numbers remain unexpectedly high for a few more months then the current maximum could be beaten. That would mean this cycle is not as weak as previously thought.

The monthly “smoothed” sunspot number is a running 13-month sunspot average, not a total from any given month. Sunspot numbers vary so radically from month to month that a running average spread over many months better reflects overall solar activity.

The blue line in the top graph above plots the smoothed sunspot number. It is always 6 months behind because the next 6 months of sunspot numbers after it are needed for the calculation. For example, last July’s smoothed number can’t be calculated until next month when January’s sunspot number comes out.

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