Our Spotless Sun

Posted by jns on April 8, 2009

Last week (on 4 April 2009, to be precise), this item came from SpaceWeather.com:

SPOTLESS SUNS: Yesterday, NASA announced that the sun has plunged into the deepest solar minimum in nearly a century. Sunspots have all but vanished and consequently the sun has become very quiet. In 2008, the sun had no spots 73% of the time, a 95-year low. In 2009, sunspots are even more scarce, with the “spotless rate” jumping to 87%. We are currently experiencing a stretch of 25 continuous days uninterrupted by sunspots–and there’s no end in sight.

This is a big event, but it is not unprecedented. Similarly deep solar minima were common in the late-19th and early-20th centuries, and each time the sun recovered with a fairly robust solar maximum. That’s probably what will happen in the present case, although no one can say for sure. This is the first deep solar minimum of the Space Age, and the first one we have been able to observe using modern technology. Is it like others of the past? Or does this solar minimum have its own unique characteristics that we will discover for the first time as the cycle unfolds? These questions are at the cutting edge of solar physics.

There was a notable period of near sun-spotless activity between 1645 and 1715 known as the Maunder Minimum. There is a description in my posting “On Reading The Little Ice Age“.

The Maunder Minimum more or less coincided with one long cooling period in Europe, making it a darling of climate-change deniers who naively want to blame every climate shift on changes in solar activity.

What dire warnings will accompany the realization of the current solar minimum? Will the threatened climate disasters rival those due to god’s wrath over gay marriage? Only time will tell.