We are now deep into solar minimum. On Sunday NOAA released its the monthly update of the solar cycle, covering sunspot activity for February 2019. As I have done every month since the start of Behind the Black, I am posting it below, annotated to give it some context.
The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.
For the second time since the beginning of the solar minimum last year, the Sun flat-lined for an month, producing no visible sunspots during the entire month of February.
That streak has continued into March. At present we are four days into March, and still no sunspots.
The big question that I will be repeating probably every month for the next two years is whether we are merely experiencing an early and possibly deep solar minimum, or the advent of a new grand minimum, with no visible sunspots for decades. During the last grand minimum in the 1600s there is evidence the Earth cooled, so much so that it was labeled the Little Ice Age. And with previous grand minimums over the past few thousand years there is evidence that similar coolings occurred. Similarly, periods where sunspot activity was high also appear to have been periods of warmer temperatures.
Why is not clearly understood, though there is some evidence that it might be related to the increasd cosmic ray flux during solar minimum.Those rays might interact with the atmosphere to produce more clouds, thus cooling the Earth. This is not proven however and remains merely a theory linked to some tentative preliminary evidence.
If we do enter a grand minimum, scientists will likely get the answers to these questions. However, we might also find ourselves experiencing significantly colder weather. I am right now flying from Chicago to Columbus, over Lake Michigan, which is filled with ice floes, something we have not seen in March for decades. Nor has this kind of cold weather been unusual for the past decade or so. Could it be because of the weak solar maximum we just experienced and the deep and extended solar minimum just before that? No one knows.
All we can do is gather data, and find out.
