Scientists design 'Sun clock' to predict solar activity that could threaten Earth's communication satellites
Space weather is driven by activities in the sun. During solar explosions, storms reach the Earth and wreak havoc by disrupting communications and causing blackouts
Scientists may have a shot at forecasting space weather in the future. A team of experts has taken the first step in that direction by designing a "sun clock". And they hope that the technology may protect astronauts in orbit and communications on Earth.
The space weather is driven by activities on the solar surface. When the sun becomes active, explosions occur on its surface, unleashing storms. It reaches the Earth and wreaks havoc. For instance, it was behind the infamous 1989 blackout, where the entire province of Canada's Quebec went without electricity for a day. Additionally, these solar flares could destroy satellites too. Astronauts exposed to these radiations may also suffer damage to their DNA.
"The ability to estimate the risk of a future solar superstorm occurring is vital for space and ground-based technologies that are particularly sensitive to space weather, such as satellites, communications system, power distribution, and aviation," lead author Professor Sandra Chapman, of the University of Warwick's Centre for Fusion, Space and Astrophysics, said in a statement.
How does it work?
The sun undergoes a cycle, which switches between two phases: the active solar maximum and the quiet solar minimum. Most often, solar storms strike when the sun's activity is high. "Large events can happen at any time but are much more likely around solar maximum. By cleanly ordering the observations we find that in 150 years of geomagnetic activity at the earth, only a few percent occur during these quiet conditions," Chapman added.
The sun begins a cycle every 11 years and its activity turns "on" at some point in the middle. The signs that mark the entry towards the active phase are sunspots, which appear as dark spots caused by strong magnetic fields. At its peak, these sunspots cover the entire solar surface.
By studying these sunspots since 1818, Chapman and her team identified a pattern in the sun's activities. Building on that, they developed a clock to predict when the star is likely to become active and set off a storm. "Scientists spend their lives trying to read the book of nature. Sometimes we create a new way to transform the data and what appeared to be messy and complicated is suddenly beautifully simple. In this instance, our sun clock method showed a clear 'switch on' and 'switch off' times demarcating quiet and active intervals for space weather for the first time," she explained.
Commenting on the study, Scott Mcintosh from the National Center for Atmospheric Research, who was involved in the study said: "We foresee that the door that this innovative work opens will lead to the development of meaningful climatologies for solar activity and improved predictability that will result from that.".
However, there are limitations. The clock cannot accurately predict when a storm will strike and how severe it might be. “We can’t predict individual events with this work,” Chapman, told Forbes. “We can quantify the chance of occurrence—how often on average we would have an event of a certain size in a given year. The solar cycle is never the same length, and our work seeks to quantify where we are in the cycle, and the effect the cycle variation has on how often space weather events are likely to occur.”
The study is published in Geophysical Research Letters.