Is the Sun Missing Its Spots? July 21, 2009Posted by honestclimate in sunspots.
Tags: climate change, global warming, solar, sun, sunspots
Is the Sun Missing Its Spots?
The New York Times, July 20, 2009
SUN GAZING These photos show sunspots near solar maximum on July 19, 2000, and near solar minimum on March 18, 2009. Some global warming skeptics speculate that the Sun may be on the verge of an extended slumber.
The Sun is still blank (mostly).
Ever since Samuel Heinrich Schwabe, a German astronomer, first noted in 1843 that sunspots burgeon and wane over a roughly 11-year cycle, scientists have carefully watched the Sun’s activity. In the latest lull, the Sun should have reached its calmest, least pockmarked state last fall.
Indeed, last year marked the blankest year of the Sun in the last half-century — 266 days with not a single sunspot visible from Earth. Then, in the first four months of 2009, the Sun became even more blank, the pace of sunspots slowing more.
“It’s been as dead as a doornail,” David Hathaway, a solar physicist at NASA’s Marshall Space Flight Center in Huntsville, Ala., said a couple of months ago.
The Sun perked up in June and July, with a sizeable clump of 20 sunspots earlier this month.
Now it is blank again, consistent with expectations that this solar cycle will be smaller and calmer, and the maximum of activity, expected to arrive in May 2013 will not be all that maximum.
For operators of satellites and power grids, that is good news. The same roiling magnetic fields that generate sunspot blotches also accelerate a devastating rain of particles that can overload and wreck electronic equipment in orbit or on Earth.
A panel of 12 scientists assembled by the National Oceanic and Atmospheric Administration now predicts that the May 2013 peak will average 90 sunspots during that month. That would make it the weakest solar maximum since 1928, which peaked at 78 sunspots. During an average solar maximum, the Sun is covered with an average of 120 sunspots.
But the panel’s consensus “was not a unanimous decision,” said Douglas A. Biesecker, chairman of the panel. One member still believed the cycle would roar to life while others thought the maximum would peter out at only 70.
Among some global warming skeptics, there is speculation that the Sun may be on the verge of falling into an extended slumber similar to the so-called Maunder Minimum, several sunspot-scarce decades during the 17th and 18th centuries that coincided with an extended chilly period.
Most solar physicists do not think anything that odd is going on with the Sun. With the recent burst of sunspots, “I don’t see we’re going into that,” Dr. Hathaway said last week.
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