Sunspots 2013: Winter Solstice Surprise!
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.
The Southern Hemisphere Rising
Another unique thing about the current solar cycle is that solar activity between the sun’s north and south hemispheres are not symmetrical. They are unbalanced. Nobody knows why that happens. It isn’t as unusual as you might think.
Last month’s southern hemisphere sunspot number was 73.9. That is the most sunspots this cycle for either hemisphere. It is the most spots since August of 2002 during Cycle 23.
This will be the 3rd cycle in a row where southern sunspot activity trails northern and there will be more than one sunspot peak. In the previous two cycles the later peaks were weaker than the first one.
The Northern Hemisphere Waning
On the other hand, northern hemisphere activity peaked at 66.1 spots way back in November of 2011. It’s been on the decline ever since.
Northern hemisphere sunspot activity peaked two years ago. The southern hemisphere is just now coming into its own.
Especially interesting is the northern hemisphere was totally devoid of any spots for half the days of December. Only a burst of northern sunspot activity between December 9th and 21st kept the northern hemisphere from falling into single digits. The north finished tied with November for its lowest activity (16.4 spots) of this cycle.
Something very dramatic will have to happen in the southern hemisphere over the next several months to beat the earlier sunspot peak from two years ago. Not impossible, but unlikely.
Recent Sun Related Climate Research
More new journal research relating solar activity to climate change has showed up this month.
The Journal of Geophysical Research published a paper by Friedrich Steinhilber and Jürg Beer forecasting solar activity for the next 500 years. Their forecast is based on two different techniques.
They predict that solar activity will drop considerably for the rest of this century. According to their research, solar activity will be more like the Dalton Minimum than the Maunder Minimum.
Frank Bosse and Fritz Vahrenholt, two German researchers, reviewed Steinhilber and Beer’s research paper and other new solar/climate links in a their own sunspot report last month – “The Sun in October 2013 – Minimum lies ahead“.
Bosse and Vahrenholt review several current lines of solar research that point toward a Dalton or Maunder-like cooling trend this century.
2013 finished as an active year in a unusually weak sunspot cycle. December turned out to be the most active month since early in Cycle 24.
Several new lines of pretty solid solar research that came out last month indicate low solar activity for the long term resulting in a cooling effect on earth’s climate.
The northern and southern hemispheres have both switched magnetic polarity. That means we should be on the downside of this cycle.
If this cycle follows in the footsteps of the previous two cycles, then solar activity will trail off quietly toward solar minimum.
However, if December’s burst of southern hemisphere solar activity continues then all bets are off.
The sun just may have a few more surprises left for Cycle 24 before all is said and done.