- Posted August 8, 2013 by
What Will Happen When the Sun’s Magnetic Poles Reverse? Sun's magnetic field flip raises EMP threat
The flip-flopping of the Sun’s magnetic field takes place at the peak of each solar activity cycle when the Sun’s internal magnetic dynamo reorients itself. When the field reversal happens, the magnetic field weakens, then dies down to zero before emerging again with a reversed polarity.
While this is not a catastrophic event, the reversal will have effects, said solar physicist Todd Hoeksema, the director of Stanford University’s Wilcox Solar Observatory, who monitors the Sun’s polar magnetic fields. “This change will have ripple effects throughout the Solar System,” he said.
When solar physicists talk about solar field reversals, their conversation often centers on the “current sheet.” The current sheet is a sprawling surface jutting outward from the sun’s equator where the Sun’s slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet.
During field reversals, the current sheet becomes very wavy, and as Earth orbits the Sun, we dip in and out of the current sheet. This means we can see an uptick in space weather, with any solar storms affecting Earth more. So, there may be more auroras in our near future.
Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy.
Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. The good news is that a wavy sheet acts as a better shield against these energetic particles from deep space.
Scientists say the Sun’s north pole is already quite far along losing its polarity, with the south pole coming along behind.
“The sun’s north pole has already changed sign, while the south pole is racing to catch up,” said Phil Scherrer, another solar physicst at Standford. “Soon, however, both poles will be reversed, and the second half of Solar Max will be underway.”
Sun's magnetic field flip raises EMP threat
“It looks like we’re no more than three to four months away from a complete field reversal,” according to Todd Hoeksema, director of Stanford University’s Wilcox Solar Observatory. “This change will have ripple effects throughout the solar system.”
NASA officials say that as the magnetic field shifts, the “current sheet” which is a surface that radiates billions of kilometers from the sun’s equator, becomes very wavy.
Since Earth orbits the sun, it dips in and out of these waves of the “current sheet.” NASA officials said that the transition from a wave to a dip creates stormy space weather around Earth.
Scientists say that the change also can provide some shielding from dangerous cosmic rays, which are high-energy particles created by supernova explosions and travel at the speed of light of approximately 186,000 miles a second or, to be exact, 299,792,458 meters per second.
However, cosmic rays are not the same as the solar flares which spew from dark spots on the sun’s surface.
Indeed, solar flare activity on the sun recently has increased as sun spots begin to shift and are aligned on a direct path toward Earth.
The solar flares create an electromagnetic pulse, or EMP, effect that can wipe out electrical grids and communications systems and fry electronics.
Some of these solar flares can be more than 20 times the size of the Earth.
Experts say that Earth experienced the largest recorded direct solar flare in 1859, which is called the Carrington Event. At the time, the only pieces of electrical equipment were the telegraph and the first parts of the trans-Atlantic cable.
The direct hit from the solar flare burned the telegraph wires, creating fires and explosions. The effects felt round the world last for three days. At the time, the trans-Atlantic cable was just being laid but also had to replaced due to the impact of the EMP on the equipment.
Since then, countries have come to be dependent on electricity, electronic components and automated control systems to survive as a society.
Experts say that a Carrington-type EMP event occurs every 100 years. However, it’s been 154 years since that event, making Earth overdue for a similar event but with more catastrophic effects on critical infrastructures due to their dependency on electricity.
A direct hit from the EMP from a solar flare not only would knock out all unprotected electronics but could subject 90 percent of world’s population to starvation and death, particularly in urban areas.
This is due to the fact that all critical infrastructures on which a technological society such as the United States depends would fail in a cascading effect once the grid is knocked out.
These critical infrastructures include telecommunications, financial and banking systems, food and water delivery, emergency services and petroleum deliveries, among others. No cash registers would work, no fuel pumps, no trucks to deliver food, no networks like phone, power and water systems — in essence, a return to an agrarian society.
In addition to the 1859 Carrington event, other notable solar flare-documented EMP events have occurred.
In 1972, a major solar flare knocked out the long-distance phone communications across some states, including Illinois, according to NASA. The event caused AT&T to redesign its power system for transatlantic cables.
In 1989, a powerful solar flare set off a major power blackout in Canada that left six million people without electricity for nine hours, The flare disrupted electric power transmission from the Hydro Quebec generating station and even melted some power transformers in New Jersey.
In 2003, a solar flare initially measured at X28 overwhelmed a spacecraft sensor measuring it. Later analysis revealed that the flare had actually reached a peak strength of X45. That solar storm was part of a string of some nine major flares that had occurred over a two-week period.