Sunday, 5 April 2009

Oh what a beautiful morning

Don't worry, I'm not going to start singing.

This happened last Thursday and I wanted to post about it then but real life intervened (nothing too bad, but enough to gobble up my free time - I might post on that later).

Anyway, it was a clear, warm, sunny morning and I was full of the joys of spring.

What put me in such a good mood? It was simple, unexpected and interesting. Early morn, before I even pulled back the curtains, I had made a coffee and was sitting at my desk when I noticed a brightness over my shoulder. There, cast on the white-painted room door, was a perfect circle of light. About 3cm across and fully in focus. The nerd in me must have kicked in because I knew what it was. My house faces due East, and a tiny chink in the curtains was making a pinhole camera and throwing an image of the rising Sun across the room. Whoa! Over the next half hour I watched the image track down, after blu-tacking a sheet of white paper on the door for better viewing. As hard as I looked though, the disc of the Sun was featureless.

Well, I kinda knew that sunspot activity was at a minimum, but no sunspots at all? Well it's true, this is the lowest sunspot minimum since 1913.

This has a knock on effect for us all. It means that satellite communications have less noise and fewer errors for instance, GPS accuracy improves and electricity grids are less prone to failure. On the minus side the displays of aurora diminish and the weaker solar wind allows more high-energy cosmic radiation to penetrate the heliosphere. This increases the radiation dose received by astronauts, a possible long term health hazard.

The Sun will recover, the 11 year cycle has been very regular since records have been kept, but interestingly the long Maunder Minimum of sunspots, from 1645 to 1715, coincided with the coldest part of the Little Ice Age when much of Europe and North America experienced extremely deep and cold winters. That was the time when the river Thames would freeze over and entire communities had to be abandoned due to the severity of the weather.

Are we entering a new 'Maunder Minimum'? Who knows. Would that be enough to offset global warming? Unlikely but Nature is endlessly fascinating.

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