The sun has been
acting outside the channel predicted over the past two centuries of decent observation and of
course everyone is curious as to what it may mean if anything at all. My own sense is that an unusual modularity
developed in the magnetic field leading to and driving these changes that at
present do not appear overly consequential.
The more
interesting question will be to see if this recurs during the next cycle and
whether the effect is more pronounced.
I suspect that may be possible and that we are observing a decadal long
super cycle working itself out.
Otherwise, it
all may mean nothing at all.
Strange Doings
on the Sun
Sunspots, Which Can Harm Electronics on Earth, Are
Half the Number Expected
ROBERT LEE HOTZ
Nov. 10, 2013
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 of sunspots
as expected and its magnetic poles oddly out of sync.
The sun generates immense magnetic fields as it
spins. Sunspots—often broader in diameter than Earth—mark areas of intense magnetic
force that brew disruptive solar storms. These storms may abruptly lash their
charged particles across millions of miles of space toward Earth, where they
can short-circuit satellites, smother cellular signals or damage electrical
systems.
Based on historical records, astronomers say the sun
this fall ought to be nearing the explosive climax of its approximate 11-year
cycle of activity—the so-called solar maximum. But this peak is "a total
punk," said Jonathan Cirtain, who works at the National Aeronautics and
Space Administration as project scientist for the Japanese satellite Hinode,
which maps solar magnetic fields.
"I would say it is the weakest in 200
years," said David Hathaway, head of the solar physics group at NASA's
Marshall Space Flight Center in Huntsville, Ala.
Researchers are puzzled. They can't tell if the lull
is temporary or the onset of a decades-long decline, which might ease global
warming a bit by altering the sun's brightness or the wavelengths of its light.
"There is no scientist alive who has seen a
solar cycle as weak as this one," said Andrés Munoz-Jaramillo, who studies
the solar-magnetic cycle at the Harvard-Smithsonian Center for Astrophysics in
Cambridge, Mass.
To complicate the riddle, the sun also is undergoing
one of its oddest magnetic reversals on record.
Normally, the sun's magnetic north and south poles
change polarity every 11 years or so. During a magnetic-field reversal, the
sun's polar magnetic fields weaken, drop to zero, and then emerge again with
the opposite polarity. As far as scientists know, the magnetic shift is notable
only because it signals the peak of the solar maximum, said Douglas Biesecker
at NASA's Space Environment Center.
But in this cycle, the sun's magnetic poles are out
of sync, solar scientists said. The sun's north magnetic pole reversed polarity
more than a year ago, so it has the same polarity as the south pole.
"The delay between the two reversals is
unusually long," said solar physicist Karel Schrijver at the Lockheed
Martin Advanced Technology Center in Palo Alto, Calif.
Scientists said they are puzzled, but not concerned,
by the unusual delay. They expect the sun's south pole to change polarity next
month, based on current satellite measurements of its shifting magnetic fields.
At the same time, scientists can't explain the
scarcity of sunspots. While still turbulent, the sun seems feeble compared with
its peak power in previous decades. "It is not just that there are fewer
sunspots, but they are less active sunspots," Dr. Schrijver said.
However, the sun isn't idle: After months of
quiescence, it unleashed vast streams of charged particles into space five
times in as many days last month, and flared again last week. Even so, these
outbursts exhibited a fraction of the force of previous solar maximums.
By comparison, a Halloween solar storm in 2003, near
the peak of the last solar maximum, was the largest of the Space Age. Even
though it mostly bypassed Earth, the storm disabled a Japanese satellite, sent
astronauts aboard the International Space Station scrambling for radiation
shelter, disrupted drilling for oil and gas in Alaska, scrambled GPS navigation
and forced the U.S. Defense Department to cancel military maneuvers.
As the solar cycle winds down in the years ahead as
part of its normal cycle, blasts of charged particles should become even less
frequent. Among other things, Earth's outer atmosphere will cool and contract,
which can extend the life of satellites by lessening the drag on them.
"That makes the commercial satellite operators
all happy," said Todd Hoeksema at Stanford University's Wilcox Solar
Observatory. "And the astronauts are happy when there is no
radiation."
Several solar scientists speculated that the sun may
be returning to a more relaxed state after an era of unusually high activity
that started in the 1940s.
"More than half of solar physicists would say
we are returning to a norm," said physicist Mark Miesch at the High
Altitude Observatory in Boulder, Colo., who studies the internal dynamics of
stars. "We might be in for a longer state of suppressed activity."
If so, the decline in magnetic activity could ease
global warming, the scientists said. But such a subtle change in the
sun—lowering its luminosity by about 0.1%—wouldn't be enough to outweigh the
build-up of greenhouse gases and soot that most researchers consider the main
cause of rising world temperatures over the past century or so.
"It may give us a brief respite from global
warming," said Dr. Hathaway. "But it is not going to stop it."
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