By Dr.S.S.Verma, Department of Physics, S.L.I.E.T., Longowal, Distt.-Sangrur (Punjab)-148 106
Other solar events include solar wind streams that come from the coronal holes on the Sun and solar energetic particles that are primarily released by CMEs. Solar flares are regular bursts of radiation that can disturb Earth’s atmosphere. They’re often accompanied by coronal mass ejections, where bubbles of magnetic fields and matter – primarily electrons and protons, but with very small traces of elements like helium and oxygen – shoot out of the sun. These particle ejections are more worrisome than the radiation from flares; once trapped in Earth’s magnetic field, they can induce massive electrical currents in the ground below that can flow into power lines. Solar flares release more than a million times more energy than that produced in volcanic eruptions. They send out mass from the outer part of the sun’s atmosphere, which creates a corona. If that energy, called a coronal mass ejection, reaches earth, it can disrupt satellites, radio traffic and electrical plants. Such solar activities are supposed to affect the Earth in many ways. Electricity is the life line of modern society and if it fails, all other critical infrastructure will fail. If a coronal mass ejection knocked out the entire power grid, it could be catastrophic. In the blink of an eye, much of humanity is catapulted back a century or two, technologically. Massive die-offs ensue as food production dives, waste management disintegrates and water distribution and communication networks fail.
History of solar flares
Solar flares are classified by the brightness of the X-rays they emit. There is just one class of flare that’s stronger than M-class: X-class. While M-class flares can sometimes cause brief radio blackouts on Earth’s poles, an X-class flare could potentially cause radio blackouts across the entire world, and create radiation storms in the upper atmosphere. Space weather has affected Earth before. In 1859, one large flare knocked out telegraph services across the Northern Hemisphere. In some cases, the operators were shocked, and machinery threw off sparks. Another hiccup came in 1989, when a coronal mass ejection led to a geomagnetic storm that caused a nine-hour power outage in Canada that affected more than 6 million people. Earth got lucky with the most recent flare, which wasn’t pointed directly at Earth; therefore, it didn’t send the brunt of its charged particles toward us, but out into space. However, we may not be so fortunate in the future, experts warned. People are worried that the next big solar storm could have even more drastic effects. The worst-case scenario is an utter nightmare: electrical grids collapse completely and can’t be restored for weeks, months, or even years.
Predicting the solar storm
In the past, the sun has always unleashed solar flares and CMEs but they were not exactly pointed toward the Earth and were also not of big size. Unfortunately, the sun and its atmosphere are devilishly hard to predict but predicting solar flares and eruptions is one of the most important goals of solar physics. New research has made it possible to extract information about Sun activities which could help scientists improve their forecast. Scientists aren’t sure exactly what causes the magnetic fields to tangle up and become unstable in the first place, but they think it has to do with movements of solar plasma. In spots where the magnetic field penetrates the visible face of the sun, plasma jostles the magnetic fields around, causing them to dance wildly, braid and snap, and ultimately reconnect with each other. Several groups of solar scientists are working on these problems, trying to plug in real data from sun-observing satellites to improve their models. The ultimate goal is to predict solar flares and eruptions so we and our satellites aren’t caught off guard the next time the sun hurls radiation our way.
Precautions
Solar activities like solar flares, CEOs, solar wind etc. are real and we should be concerned. Solar flares take just less than nine minutes to reach Earth (same as sunlight), the coronal mass ejections lag behind by a couple of days. NASA is predicting that the coming solar maximum could produce very energetic solar flares and coronal mass ejecta. Apparently the concern is that in future the sun will reach a stage of its cycle when these large events are more likely. These events have the potential to cause significant damage to our power grid as well as our orbiting satellites. Preventive measures can be taken like – satellites can be sent offline during big flares, power grids and communication networks can be shielded against electromagnetic radiation and so on. Scientists conclude that there are ways to mitigate the power grid’s vulnerability to coronal mass ejections by implementing special transformers that allow its electrical grid to deal with geomagnetic storms. Then power grids can distribute power and reduce their loads to protect themselves. Also, development of other technologies could help protect electronic devices that we use every day. But again, this requires investments by manufacturers that, so far, have been unwilling to make such a commitment. Satellite and power companies are also trying to design technology that can better withstand the higher radiation loads unleashed by solar storms. Still, scientists would like to offer more advanced warnings when big storms are headed our way. Another precaution is to implement early warning systems. If we see such a coronal mass ejection, we may only have 18 hours or less before the particle flux reaches Earth. Therefore, closely monitoring the Sun’s activity and then being able to act on information in a short time is vital. Of course, if those precautions are taken, and actually work, little damage will be done.