Uh, thought the great issue was global warming!

So just a day after the 2011 Summer Solstice, the sun is again a topic on this Blog.

Last Saturday’s issue of The Economist had amongst it’s leaders, a piece with the headline of Several lines of evidence suggest that the sun is about to go quiet.

Coincidentally I had seen, just a few hours previously, a similar story on the UK website The Register.  Let me quote a little from that item.

Earth may be headed into a mini Ice Age within a decade

Physicists say sunspot cycle is ‘going into hibernation’

By Lewis Page • Posted in Science, 14th June 2011 17:00 GMT

What may be the science story of the century is breaking this evening, as heavyweight US solar physicists announce that the Sun appears to be headed into a lengthy spell of low activity, which could mean that the Earth – far from facing a global warming problem – is actually headed into a mini Ice Age.

The announcement made on 14 June (18:00 UK time) comes from scientists at the US National Solar Observatory (NSO) and US Air Force Research Laboratory. Three different analyses of the Sun’s recent behaviour all indicate that a period of unusually low solar activity may be about to begin.

It was a moment’s effort to go to the US National Solar Observatory website (great website, by the way) and read that recent press release.  The press release link is here and it really is a ‘must read’ item.  Here’s just a flavour of what was written,

WHAT’S DOWN WITH THE SUN?
MAJOR DROP IN SOLAR ACTIVITY PREDICTED

A missing jet stream, fading spots, and slower activity near the poles say that our Sun is heading for a rest period even as it is acting up for the first time in years, according to scientists at the National Solar Observatory (NSO) and the Air Force Research Laboratory (AFRL).

As the current sunspot cycle, Cycle 24, begins to ramp up toward maximum, independent studies of the solar interior, visible surface, and the corona indicate that the next 11-year solar sunspot cycle, Cycle 25, will be greatly reduced or may not happen at all.

“This is highly unusual and unexpected,” Dr. Frank Hill, associate director of the NSO’s Solar Synoptic Network, said of the results. “But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.”

Spot numbers and other solar activity rise and fall about every 11 years, which is half of the Sun’s 22-year magnetic interval since the Sun’s magnetic poles reverse with each cycle. An immediate question is whether this slowdown presages a second Maunder Minimum, a 70-year period with virtually no sunspots during 1645-1715.

Hill is the lead author on one of three papers on these results being presented this week. Using data from the Global Oscillation Network Group (GONG) of six observing stations around the world, the team translates surface pulsations caused by sound reverberating through the Sun into models of the internal structure. One of their discoveries is an east-west zonal wind flow inside the Sun, called the torsional oscillation, which starts at mid-latitudes and migrates towards the equator. The latitude of this wind stream matches the new spot formation in each cycle, and successfully predicted the late onset of the current Cycle 24.

“We expected to see the start of the zonal flow for Cycle 25 by now,” Hill explained, “but we see no sign of it. This indicates that the start of Cycle 25 may be delayed to 2021 or 2022, or may not happen at all.”

As I said, the item is essential reading and the full release may be read here.  Another benefit of going to that NSO press release is that you will find another link to the full text and pictures.  The pictures are just stunning.  Here’s one of them.

Seriously, if you are interested in learning more about our Sun and the nature of solar cycles, this strikes me as an excellent place to start.

However, let me close this article by returning to the final paragraphs of that NSO Press Release.  Here they are,

All three of these lines of research to point to the familiar sunspot cycle shutting down for a while.

“If we are right,” Hill concluded, “this could be the last solar maximum we’ll see for a few decades. That would affect everything from space exploration to Earth’s climate.”

In response to news inquiries and stories, Dr. Frank Hill issued a follow-up statement:

“We are NOT predicting a mini-ice age. We are predicting the behavior of the solar cycle. In my opinion, it is a huge leap from that to an abrupt global cooling, since the connections between solar activity and climate are still very poorly understood. My understanding is that current calculations suggest only a 0.3 degree C decrease from a Maunder-like minimum, too small for an ice age. It is unfortunate that the global warming/cooling studies have become so politically polarizing.”

Just take that last quotation from Dr. Frank Hill and ponder, “It is unfortunate that the global warming/cooling studies have become so politically polarizing.” [my italics].

That statement from Dr. Hill combined with my friend Dan’s posting of the 16th are food for thought.  More about this on Learning from Dogs soon.