[SFDXA] Sun Flatlining Into Grand Minimum, Says Solar Physicist Bruce Dorminey

[WILLIAM MARX]

Sun Flatlining Into Grand Minimum, Says Solar Physicist Bruce Dorminey
http://www.forbes.com/sites/brucedorminey/2014/01/20/sun-flatlining-into-grand-minimum-says-solar-physicist/


 
First official sunspot belonging to the Solar Cycle 24. (Photo credit: Wikipedia)
With each passing season, the weather seems stranger and more extreme.
Who can argue with a sudden outbreak of the “polar vortex” 
phenomenon; unprecedented winter drought in California; and summer 
temperatures so torrid Down Under that even play at the Australian Open 
was briefly halted?
Is any of this connected to the sun’s drastically diminished recent sunspot cycles?

Weather isn’t climate, but circumstantial evidence indicates our 
sun may be entering a grand minimum of sunspot activity, not unlike the 
Maunder Minimum that some climatologists think caused record low winter 
temperatures in Northern Europe during the latter half of the 17th century.
“My opinion is that we are heading into a Maunder Minimum,” said Mark Giampapa, a solar physicist at the National Solar Observatory (NSO) in 
Tucson, Arizona. “I’m seeing a continuation in the decline of the 
sunspots’ mean magnetic field strengths and a weakening of the polar 
magnetic fields and subsurface flows.”

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Theoretical details of how sunspots are actually produced continue to be debated. But one popular idea is that they are generated as the result of concentrated and twisted solar magnetic fields 
blocking internal convection in the outer third of the sun’s interior. 
This, in turn, gives the sunspots their dark appearance, since on 
average they are 2000 degrees cooler than the surrounding solar plasma.
These solar magnetic fields are thought to be triggered by the sun’s 
own internal “differential rotation.” That is, the fact that at various 
latitudes and depths, the sun’s gaseous plasma rotates at different 
rates. Then once these fields are produced, some theorists think it’s 
their interaction at the sun’s photosphere (or surface) that plays a 
crucial role in sunspot creation.
Even so, David Hathaway, a solar physicist at NASA Marshall Space 
Flight Center in Huntsville, says it’s the actual strength of such 
magnetic field at the end of a given maximum 11-year sunspot cycle that 
are thought to act as bellwethers for the size and strength of the next 
solar maximum.
“At the end of a sunspot cycle about all you have left are magnetic 
fields at the solar poles,” said Hathaway. “We’re at the sunspot maximum of Cycle 24. It’s the smallest sunspot cycle in 100 years and the third in a trend of diminishing sunspot cycles. So, Cycle 25 could likely be 
smaller than Cycle 24.”
Another indicator pointing to an imminent grand minimum is that the 
current solar cycle shows some signs of hemispheric asymmetry, says 
Steve Tobias, an applied mathematician at the University of Leeds in the U.K.
“When the field is about to enter a minimum or is leaving a minimum,” said Tobias, “we see more sunspots in one solar hemisphere than the 
other.”
Yet during the 1645 — 1715 Maunder Minimum itself, sunspots basically disappeared and as documented in paintings from the era, Northern 
Europe suffered unusually cold winter temperatures.
Such minima are thought to be a part of the normal life of a sunlike 
star, however. And from recent surveys of several solar analogues in the open stellar cluster M67, Giampapa and colleagues see indications that 
such grand minima take place up to 15 percent of the time.
Hathaway says that the observed effects of the sunspot cycle in 
radioisotopes; in ice cores; and in tree rings indicate that some 10 to 
15 percent of the time the sun is in “something like a Maunder Minimum.”
 
This Bruegel painting “The Hunters in the 
Snow” is reminiscent of winter landscapes typical in Northern Europe 
during the Maunder Minimum. (Photo credit: Wikipedia)
“If we’re entering a Maunder Minimum, it could persist until the 
2080s,” said Giampapa, who points out that if such a minimum’s primary 
effect is cooling, it could wreak havoc by curtailing agricultural 
growing seasons which, for instance, could lead to lower wheat 
production in breadbasket economies.
But Giampapa says it could also mean a global excursion from the 
mean, resulting in local climate extremes in terms of both anomalous 
temperatures and precipitation.
Could a Maunder Minimum mitigate a warming climate?
Not likely, says Hathaway.
Although the rise of global temperatures seen in “the last decade or 
so seems to have currently leveled off,” says Hathaway, he notes that 
even a Maunder Minimum would still not be enough to counter the warming 
effects of anthropogenic climate change.
If anything, a Maunder Minimum may simply make existing weather and 
short term climate even more unusual and difficult to predict.

http://www.forbes.com/sites/brucedorminey/2014/01/20/sun-flatlining-into-grand-minimum-says-solar-physicist/