By most indicators, the Sun is not behaving as expected at this point in the solar cycle – and it hasn’t been for quite a while. The most visible indicator of solar activity – the number of sunspots – is far lower than normal. Over the last few days, the Sun’s surface facing Earth has been spotless.
We are currently in Solar Cycle 24.
The figure on the right, above, is a composite of historical monthly sunspot numbers as of early December from NOAA’s Space Weather Prediction Center superimposed over the same figure from March 2007. The red lines represent the 2007 predicted maximum and minimum monthly sunspot counts. The current average monthly count, which should be ramping up to the cycle’s maximum, is far below what was anticipated.
picture
In a paper published March 2006, David Archibald predicted that Solar Cycles 24 and 25 would be very much like Solar Cycle 5 and 6 – the Dalton Minimum. Nearly two years into Cycle 24, the pattern he predicted appears to be developing.
So what was the Dalton Minimum and what might a similar period mean for the modern world?
Bottom line – it’s going to get colder.
The Dalton Minimum was a period of low solar activity that lasted from about 1790 to 1830 in which global temperatures were also lower than average. If we are entering into a similar “modern” minimum and the correlation of colder global temperatures hold true, global “warming” may stop and global temperatures may drop through the end of the minimum.
By many indicators, global temperatures appear to have been relatively stable for nearly a decade – or more – already, except for perturbations caused by climate features such as the Arctic Oscillation, El Nino, and La Nina.
Some scientists believe that the recent warming that has been seen is simply a natural recovery from the cold period of the Little Ice Age, which may have resulted from several low solar activity periods. If that is the case, even if temperature were to drop over the next couple of decades, the overall trend, since the end of the Little Ice Age, may be maintained, temperatures may drop for the next 20 to 30 years.
Previous related posts:
- The Sun Has Lost Its Spots, January 31, 2009
- It’s going to get frosty, March 19, 2009
- The Sun Has Lost Its Spots – Part 2, April 6, 2009
- The Sun has found some spots – May 1, 2009
- The Sun has lost its spots – part 3 – June 28, 2009
- 700 blank days and counting – August 27, 2009
- The Sun has lost its spots – part 4. – September 17, 1010
