Sunspot Activity at Record Low, And Magnetic Orientation Is Puzzling
The Wall Street Journal reported yesterday that this sun’s solar maximum is the weakest in 200 Years:
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.
“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.
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.
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.”
In January, Nasa warned that we might be on the verge of another “Maunder minimum” … where low solar output leads to a mini ice age.
We could be heading into another Maunder minimum … or a shorter and less severe cooling trend.
The truth is that no one knows. As Reuters reported earlier this year:
Giuliana DeToma, a solar scientist at the High Altitude Observatory in Colorado … admitted “we will do not know how or why the Maunder Minimum started, so we cannot predict the next one.”
Many solar experts think the downturn is linked a different phenomenon, the Gleissberg cycle, which predicts a period of weaker solar activity every century or so. If that turns out to be true, the sun could remain unusually quiet through the middle of the 2020s.
But since the scientists still do not understand why the Gleissberg cycle takes place, the evidence is inconclusive. The bottom line is that the sun has gone unusually quiet and no one really knows why or how it will last.
Indeed, scientists are largely mystified by the sun, and are just starting to learn about interactions between the sun and the Earth.
For example, the Wall Street Journal notes:
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.