Friday, April 30, 2010
The Quiet Sun
Last year, 260 days were without sun spots (71 %). This year only 21 days (17%) have had no visible sun spots. Most of them were recently, nearly two weeks worth, and the thing that broke the chain, was a micro tiny sun spot yesterday which barely lasted 15 hours. The normal "resting time" between peaks of sun spot activity, the solar minimum period, is 485 days. Our minimum has lasted 791 days.
The 10 cm radio flux density from the sun is now 75. This flux density number ranges between 64 and 267; so the lower range fits the inactivity of very recently. It had peaked in the low 90s just a few months ago.
So, are we in a Maunder like minimum which will lead to big temperature drops as with the Little Ice Age beginning in the 1600s? Unlikely. What we may well see is a very short lived minimum, like the Dalton minimum, which resulted in the Russian winter which doomed Napoleon and the Grand Armee. But the sun could become very active very quickly.
The magnitude of solar magnetism, which results in sun spots, has been decreasing lately. If it declines below 1500 gauss, the solar scientists say there will be no sun spots. That could be bad.
Labels: Global Warming; Sun Spots