Over a repeating cycle of 11 years, the sun develops a chronic case of recurring acne, its face becoming pockmarked with ugly black spots and blemishes which eventually fade away only to reappear again in the following cycle.
These “sun spots” reflect the slow twisting of magnetic field lines inside the sun, caused by the sun’s rotation, which traps potential energy until enough explosive force is built up to blast solar plasma out into space in giant flares and coronal mass eruptions.
If we take a look at the sun’s corona, a halo of super hot gas surrounding the sun, we discover that the sun-spot cycle is accompanied by variations in coronal brightness with an unblemished sun radiating less energy than a spotty one.
We should be approaching another sun spot maximum in 2012, but observations are troubling scientists. There are no black spots appearing at all! It’s the quietest it’s been for almost a century.
During the last extended period of solar inactivity, between 1790 and 1830, referred to as the Maunder minimum, the cooling effect was such that the Earth was thrown into a mini ice age when it was all the rage to go ice skating on the Thames.
Are we approaching another Maunder minimum? Reason to start burnishing those ice skates? Enough to counter global warming? A pressing question given that global temperatures have stopped rising since the turn of the century despite continuing increases in C02 levels. Keep an eye on http://spaceweather.com to keep abreast of this chilling issue.
This blog was writtin in 2009 for the BCA Magazine, since then the gloomy prognosis has not been realised.