Solar flares are intense bursts of light from the Sun. They are created when complicated magnetic fields suddenly and explosively rearrange themselves, converting magnetic energy into light through a process called magnetic reconnection — at least that's the theory because the signatures of this process are hard to detect. But during a December 2013 solar flare, three solar observatories captured the most comprehensive observations of an electromagnetic phenomenon called a current sheet, strengthening the evidence that this understanding of solar flares is correct.
These eruptions on the Sun eject radiation in all directions. The strongest solar flares can impact the ionized part of Earth's atmosphere — the ionosphere — and interfere with our communications systems, like radio and GPS, and also disrupt onboard satellite electronics. Additionally, high-energy particles, including electrons, protons, and heavier ions, are accelerated by solar flares.
Unlike other space weather events, solar flares travel at the speed of light, meaning we get no warning that they're coming. So scientists want to pin down the processes that create solar flares and even some day predict them before our communications can be interrupted.
"The existence of a current sheet is crucial in all our models of solar flares," said James McAteer from New Mexico State University in Las Cruces. "So these observations make us much more comfortable that our models are good."
And better models lead to better forecasting, said Michael Kirk from NASA's Goddard Space Flight Center in Greenbelt, Maryland. "These complementary observations allowed unprecedented measurements of magnetic reconnection in three dimensions," Kirk said. "This will help refine how we model and predict the evolution of solar flares."
Looking at current sheets
A current sheet is a fast flat flow of electrically-charged material, defined in part by its extreme thinness compared to its length and width. Current sheets form when two oppositely aligned magnetic fields come in close contact, creating high magnetic pressure. Electric current flowing through this high-pressure area is squeezed, compressing it down to a fast and thin sheet. It's a bit like putting your thumb over the opening of a water hose — the water, or in this case the electrical current, is forced out of a tiny opening much faster. This configuration of magnetic fields is unstable, meaning that the same conditions that create current sheets are also ripe for magnetic reconnection.
"Magnetic reconnection happens at the interface of oppositely-aligned magnetic fields," said Chunming Zhu from New Mexico State University. "The magnetic fields break and reconnect, leading to a transformation of the magnetic energy into heat and light, producing a solar flare."
Because current sheets are so closely associated with magnetic reconnection, observing a current sheet in such detail backs up the idea that magnetic reconnection is the force behind solar flares.
"You have to be watching at the right time, at the right angle, with the right instruments to see a current sheet," said McAteer. "It's hard to get all those ducks in a row."
This isn't the first time scientists have observed a current sheet during a solar flare, but this study is unique in that several measurements of the current sheet — such as speed, temperature, density, and size — were observed from more than one angle or derived from more than one method.
This multi-faceted view of the December 2013 flare was made possible by the wealth of instruments aboard three solar-watching missions: NASA's Solar Dynamics Observatory, NASA's Solar and Terrestrial Relations Observatory, which has a unique viewing angle on the far side of the Sun, and Hinode, which is a collaboration between the space agencies of Japan, the United States, the United Kingdom, and Europe led by the Japan Aerospace Exploration Agency.
Even when scientists think they've spotted something that might be a current sheet in solar data, they can't be certain without ticking off a long list of attributes. Since this current sheet was so well observed, the team was able to confirm that its temperature, density, and size over the course of the event were consistent with a current sheet.
As scientists work up a better picture of how current sheets and magnetic reconnection lead to solar eruptions, they'll be able to produce better models of the complex physics happening there, providing us with ever more insight on how our closest star affects space all around us.
The sun is a benign star but at times it can blow its top, blasting out a solar flare that if aimed towards the earth can create problems for us. It can disturb radio communications and GPS systems and also affect orbiting satellites.
An Irish scientist is involved in a research group that believes it has figured out how these massive flares occur, and are now working to see if they can predict them.
It was a lucky break for the researchers when no fewer than three orbiting solar-watching missions all had a look at the one place at the one time and got an unprecedented view of a flare in action.
“You have to be watching at the right time, at the right angle, with the right instruments to see a [developing flare]now we only had models to explain what the sun was up to, he said. And even if their models seemed pretty sound, achieving that kind of observation and later analysis of the data makes them even more confident that their models are correct.
Solar flares have to do with powerful magnetic fields crossing the sun. When two fields come together they produce powerful electric currents. This is like a firework with a lit fuse because soon after forming the fields “reconnect” and a solar flare kicks off.
But what happens to the electric current or current sheets associated with the magnetic fields?
The observations allowed them to confirm that the current sheets are part of the process and are there when reconnection fires off a flare. He and lead author Dr Chunming Zhu and colleagues published their findings on Tuesday in Astrophysical Journal Letters.
“This was the missing aspect, the smoking gun, the thing that we knew was there but we had to find,” Prof McAteer said.
These new findings might open the way to being able to predict when flares are about to happen, he said. “We are confident the models are right and with that confidence that the models are correct maybe we can project into the future.”
A large solar flare could push us all back into the Dark Ages for years, with no internet, satellite communications, mobile or landline telephones, electricity and all the millions of medical and other devices that rely on today’s communications systems and electrical power to operate, says Louis Lanzerotti, distinguished research professor at New Jersey Institute of Technology’s Center for Solar-Terrestrial Research.
Prof. Lanzerotti was speaking at a Symposium of Space Weather that was held in Washington DC last week.
At a push, we would all manage to survive without our smartphones, but how long would we manage with no electricity? What would happen to us if it took several years to get everything back to normal?
The specter of a geomagnetic solar storm with the power to disrupt or destroy communications satellites, mess up GPS systems, bring air travel to a halt, turn off telephones, computers and lights in our homes, offices and streets across the world for weeks, months, or even years, is something most members of the general public have no idea about.
However, this is a scenario that insurance companies worldwide, government agencies from national security departments to space agencies to parliaments, and scientists take very seriously.
Those who are aware of the potential problem call it ‘The Big One’ – they say this ‘low probability but high-impact event’ merits a significant push on several fronts, including forecasting, research and mitigation strategy.
Space weather experts come together
The Washington Symposium – Space Weather Science and Applications: Research for Today, Training for Tomorrow – drew space weather experts from the federal government, academia, private industry and the military.
Solar Flare artist impressionAn artist’s impression of a superflare. A stellar superflare was detected on a nearby star by NASA’s Swift satellite. Had such a powerful flare come from our Sun it would have triggered a mass extinction on Earth.
Regarding a colossal, well-timed solar storm for today’s global society, which is firmly-attached to a high-tech, electrically-powered umbilical crod, Prof. Lanzerotti said:
“Since the development of the electrical telegraph in the 1840s, space weather processes have affected the design, implementation and operation of many engineered systems, at first on Earth and now in space.”
“As the complexity of such systems increases, as new technologies are invented and deployed, and as humans have ventured beyond Earth’s surface, both human-built systems and humans themselves become more susceptible to the effects of Earth’s space environment.”
Apart from disrupting our energy and communication grids, what is generally known as space weather – strong bursts of electromagnetic radiation, magnetized plasma and energetic charged particles – could corrode our water and sewer pipelines, erase everything we have stored in our computer memory, harm astronauts out in space, and undermine security and military operations.
The symposium was sponsored by the Space Policy Institute at George Washington University and the Universities Space Research Association (USRA). It focused on the ever-growing urgency of both the development and creation of practical applications in the field and basic scientific research.
Daniel Baker, Director of University of Colorado-Boulder’s Laboratory for Atmospheric and Space Physics (LASP), said “Once systems start to fail, [the outages] could cascade in ways we can’t even conceive.”
Dr. Baker is also a panelist who recommends greater support for the development and creation of engineering systems and devices that can protect Earth’s infrastructure.
Deadly superflare hits once a thousand yearsScientists from Denmark, Italy and China reported last month that a superflare, like the one observed on other stars, coming from our Sun could destroy much of life on Earth. They believe that Earth suffers the effects of a superflare every 1,000 years. (Image: https://theextinctionprotocol)
Recovery would cost trillions
A 2013 report published by Lloyd’s of London (Lloyd’s), an insurance market located in London’s primary financial district, estimated that a massive storm would directly affect twenty to forty million people for up to two years, depending ‘largely on the availability of spare replacement transformers’.
To recover from such a solar flare would cost from $600 billion to $2.6 trillion.
This symposium follows one last year – Space Weather: Understanding Potential Impacts and Building Resilience – held in Washington D.C. organised by the Executive Office of the President of the United States and attended by engineers and scientists from industry and academia, as well as politicians and policymakers.
In that symposium, the OSTP laid out a multi-part plan to deal with, as Prof. Lanzerotti put it, ‘civil societal issues related to all aspects of space weather.’ OSTP stands for Office of Science and Technology Policy – it is a department of the United States government, part of the Executive Office of the President.
The sun unleashed its most intense flare of the year Tuesday (May 5), a monstrous blast that caused temporary radio blackouts throughout the Pacific region.
The X-class solar flare — the most powerful category of sun storm — erupted Tuesday from a sunspot called Active Region 2339 (AR2339), peaking at 6:11 p.m. EDT (2211 GMT). NASA's Solar Dynamics Observatory spacecraft captured a recording it in multiple wavelengths of light.
Despite the radio blackouts, the blast is unlikely to cause major issues here on Earth, researchers said.
A solar flare is a release of magnetic energy from the sun. The energy is stored as a magnetic field around the sun, and then is released with energetic particles and waves coming from the solar surface.
Huge amounts of energy are released during solar flares, which can be spectacular events.
These solar flare events are related to a process called magnetic reconnection, or the annihilation of the magnetic field.
There are magnetic fields that are of opposite polarity, with some magnetic fields going one direction and other magnetic fields going the opposite way.
When these opposing magnetic fields come into contact, reconnection occurs and may be explosive, as in the case of solar flares.
Scientists still debate the cause of the explosions. In general, the sun is undergoing an 11-year cycle called the solar cycle that affects the sun’s radiation, number of solar flares and number of sun spots.
This cycle reflects fluctuations in solar activity and changes the polarity of the sun every 11 years.
Solar flares can affect life on Earth in a number of ways. They are responsible for beautiful natural phenomena like the auroras.
Scientists today are most concerned about effects on sensitive radioelectronic equipment up in orbit. Solar flares can damage this equipment in orbit, affect communications systems on airplanes, or even short-circuit electronic systems on the ground.