Green Energy

Wherefore Art Thou, Global Warming?

From New Scientist:

Even the sun needs a break. A slowdown in solar activity has given us the first real clue about a period of dramatic solar behaviour 350 years ago.

In 2008, the sun entered a deep lull in magnetic activity. Spacecraft measurements show that this caused a belt of sluggish particles, known as the slow solar wind, to thicken. Produced near the sun's equator, the belt is normally narrow and ruched like a ballerina's tutu. The particles there flow at about 336 kilometres a second, as opposed to 550 kilometres a second in the fast solar wind produced closer to the sun's poles.

Because Earth orbits at a 14 degree tilt relative to the sun's equator, it passes in and out of these ruches during the year. As solar activity dwindles, the belt thickens, and we spend more time passing through it. The speed of the slow solar wind affects the temperature of Earth's upper atmosphere, and impacts climate.

To find out how severe such slowdowns might be, Mike Lockwood and Matt Owens at the University of Reading, UK, used the 2008 measurements to model the belt's thickness during the most extreme solar minimum on record: the Maunder Minimum. This lasted from 1645 to 1715 and corresponded to a minor ice age.

The model showed that the solar wind speed probably dropped to just 250 to 275 kilometres a second during this period. Earth spent six months of the 2008 minimum in the slow solar wind, but it probably spent all 70 years of the Maunder Minimum there.

Lockwood says the current weak cycle could herald the sun dipping intoanother extended period of inactivity. The temperature of Earth's upper atmosphere affects the speed at which satellite orbits decay, so a prolonged drop in the solar wind speed would cool and shrink the atmosphere and diminish the drag on satellites. This would exacerbate the space junk Movie Camera

problem because debris would be slower to re-enter Earth's atmosphere, where it burns up harmlessly.

But don't expect another mini ice age, says Lockwood. The Maunder Minimum was also characterised by an almost total lack of sunspots, which record how the solar dynamo, which creates the sun's magnetic field, is churning. We still do not understand that well enough to predict when another Maunder Minimum might occur.

"Until we know why the sun occasionally drops into these grand minima, we won't really understand the solar dynamo," says Lockwood.

- Strange Doings On The Sun: Sunspots, Which Can Harm Electronics On Earth, Are Half The Number Expected
I'm sure they'll figure some way to blame this on Capitalism. From the Wall Street Journal: Something is up with the sun. Scientists say that solar activity is stranger than in a century or more, with the sun producing barely half the number...

- Obama:if You Like Your Global Warming You Can Keep Your Global Warming
Obama orders government to prepare for impact of global warmingPresident Obama issued an executive order Friday directing a government-wide effort to boost preparation in states and local communities for the impact of global warming.The action orders...

- Bbc – Real Risk Of A Maunder Minimum ‘little Ice Age’
From Watts Up With That: It’s known by climatologists as the ‘Little Ice Age’, a period in the 1600s when harsh winters across the UK and Europe were often severe. The severe cold went hand in hand with an exceptionally inactive sun, and was...

-
Dawn of a new 'Maunder Minimum'? Solar Activity Drops to 100 Year Low From Will at THE OTHER NEWS:Great Britain last winter Dawn of a new 'Maunder Minemum'? Solar Activity Drops to 100 Year Low.HT: IceAgeNow. “The current...

-
NASA Admits Solar Activity Causes Global Warming “NASA spokeswoman Beth Dickey confirmed with SPACE.com earlier today that the reason [satellite] UARS is expected to fall early in its re-entry window is because of the sharp uptick in solar activity....

Green Energy