Star Phoenix Base

By David L. Brown

This is a follow-up to my post of June 29 titled “Could Quiet Sun Offset Global Warming?” (see it here.) In that piece I reported on the failure of the Sun to return to its maximum sunspot cycle, remaining a blank and featureless orange disk. As I wrote, if we are entering a new extended minima as has happened in the past, most notably during the Maunder Minimum in the 16th and 17th centuries, it could have a significant effect on global warming. High sunspot activity actually increases the amount of heat put out by the Sun, and thus an extended minima could give us a respite from global warming, helping to offset the effects of greenhouse gases.

On July 9th I followed up with a brief item titled “Sun Begins to Show Its Spots,” reporting on the appearance of a rather small and unexciting outbreak of spotting. However, that seems to have been a false alarm, since the Sun quickly returned to a condition of “Code Orange.” At left is the way it appears today, plain as a billiard 5 ball (but without the number). In fact, the similarity is so exact that I thought it would be worth posting a comparison image, as at the right below

Astronomers are vexed at the Sun’s failure to return to its usual cycle of sunspots. According to the SpaceWeather.com site, which tracks the Sun on a daily basis, the number of spot free days during 2008 was the highest since 1913 — and so far 2009 has seen even fewer spots. The average number of spotless days during an average minima is 485, and in this cycle we have already observed 733 spot-free days with no end in sight.

The Maunder Minimum is associated with the event known as the Little Ice Age, so this is a subject we should be aware of. Of course, as global warming progresses we are in no danger of any new ice ages, little or not, but at least there may be a respite from the rising temperature. I will keep an eye on this phenomenon and make occasional reports.

By David L. Brown

What is wrong with this picture? It is our Sun, as photographed a few days  ago. And what is wrong is that it shows no sign of sunspots, none at all. And that is a cause for curiosity because the low point in the usual 11 year sunspot cycle was supposed to have ended well over a year ago, and yet for day after day, week after week, month  after month the Sun continues to present a blank, featureless face to the Universe. The return of spots to the surface of the  Sun is now about 18 months past due.

Scientists do not have an explanation for this, but there are historic precedents. During the 17th and 18th Centuries the Sun entered an extended period of quiescence during which virtually no sunspots were observed. Dubbed the Maunder Minimum, the anomalous period lasted from about 1645 to 1715.

Does this mean anything to we humans here on Earth? After all, what difference could it make whether the Sun exhibits spots or appears like a featureless orange ball? Well, it could mean a lot. Many climate scientists relate the Maunder Minimum and other periods of low activity on the Sun with cooling. In fact, the event called the  Little Ice Age appeared to be connected in time with the Maunder Minimum, suggesting a correlation between the two.

To understand just how unusual the Maunder Minimum was, during one 30-year period of the event astronomers observed only about 50 sunspots. In modern times, 40,000–50,000 spots would have been observed during that length of time. That represents a reduction on the order of a thousandfold.

Now you may have learned that sunspots are cool eruptions on the surface of the solar disc, so at first glance it may seem that more sunspots, not fewer, would result in cooling. But the areas around a sun spot are hotter than the average surface temperature of the Sun, resulting in a higher total output of radiation.

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By David L. Brown

Energy Secretary Steven Chu has stated that if we were to paint all flat roofs white it would reflect solar rays back into space and help reduce global warming. Well, maybe. Let’s take a look at what might be called the “albedo” solution.

The term “albedo” refers to the reflectivity of an object. It is most often used in astronomy to denote  the percentage of the Sun’s light that is normally reflected by a particular planet or other object. For example, the Moon reflects a paltry 12 percent on average, yielding an albedo index of 0.12. Venus, the brightest planet, reflects 65 percent for an albedo of 0.65. The Earth has an albedo of 0.37. These figures are averages for the entire surface of each object, so reflectivity could vary widely from place to place. For example on the Earth solar rays will strike bright white clouds in some locations and dark volcanic rock in others.

Albedo already plays an important role in the Earth’s ability to maintain temperature levels. Snow and ice in the Arctic and Antarctic reflect a lot of heat back into space. A serious concern about the ongoing loss of Arctic Ocean sea ice is the fact that dark open water will absorb a lot of heat that would previously have reflected off of the white snow and ice. Summer ice coverage has been shrinking, causing the Arctic to warm faster than any other region on the planet. This is called a feedback effect, since the more ice melts, the warmer the area will become, causing even more melting and so on.

Sec. Chu’s proposal to paint rooftops white is presumed to cool the Earth by raising the average albedo of the planet. He also noted that roads and sidewalks should also be made “lighter colored” to enhance the effect.

Dr. Chu is a Nobel Prize winning physicist and his ideas should not be discarded out of hand. Not surprisingly, FoxNews.com contributor Steven Milloy, known for his commentary on so-called “Junk Science” (www.junkscience.com) does exactly that. “It’s past simplistic — it’s ridiculous,” FoxNews.com quotes the avowed climate-change skeptic in this article. “Imagine the glare on roads, in urban areas, imagine the UV radiation bouncing around. Snow blindness would be replaced by road blindness.”

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