Sun Spotless For 42 Days And Counting

Seen at Watts Up With That:

On August 31st, at 23:59 UTC, just a little over 24 hours from now, we are very likely to make a bit of history. It looks like we will have gone an entire calendar month without a sunspot. According to data from NOAA’s National Geophysical Data Center, the last time that happened was in June of 1913. May of 1913 was also spotless.

With the current space weather activity level of the Sun being near zero, and the SOHO holographic imaging of the far side of the sun showing no developing spots that would come around the edge in the next 24 hours, it seems a safe bet to conclude that August 2008 will be the first spotless month since June 1913.[…]

As commenter Jim Powell points out,

There was a stretch of 42 spotless days from 9/13/1996 to 10/24/1996. Today we have equaled this period. Check out Jan Janssens spotless days page http://users.telenet.be/j.janssens/Spotless/Spotless.html.

The Belgian chart cited shows that a 42-day span is the 10th-longest spotless span in the past 160ish years.  If we go another week without a sunspot, we would be tied for fourth position.

So, why do sunspots matter?  Well, there is a school of thought that periods of low sunspot activity are closely correlated with cooler-than-normal periods on earth.  (See Wikipedia entries on the Dalton and Maunder minimums.)

This opens the door to the question: so, what happens when solar-generated global cooling meets human-influenced global warming?