Sightings of one of nature’s most spectacular visual displays may become a thing of the past in Scotland and the UK due to major shifts in the sun’s activity predicted to take place in the next few decades, according to new research.
Studies by space scientists at the University of Reading suggest the aurora borealis, or northern lights, may become a rare phenomenon except in the area closest to the north pole.
The same applies in reverse for the aurora australis, known as the southern lights, which can currently be seen from Chile, Argentina, New Zealand, and Australia.
The findings show that decreasing solar activity will shrink the overall size of the sun’s “atmosphere” by a third and weaken its protective influence on earth.
This could result in the aurora becoming a less common occurrence away from the north and south polar regions for half a century or more.
Lead researcher Dr Mathew Owens, from the university’s meteorology department, said: “The magnetic activity of the sun ebbs and flows in predictable cycles, but there is also evidence that it is due to plummet, possibly by the largest amount for 300 years.
“If so, the northern lights phenomenon would become a natural show exclusive to the polar regions, due to a lack of solar wind forces that often make it visible at lower latitudes.”
Sunspot records going back 400 years were used to reconstruct what happened the last time the earth experienced such a dramatic dip in solar activity – more than three centuries ago.
The researchers used updated models and contemporary reports to predict what could happen during a similar event in the future, which is likely to occur in the next few decades.
The scientists believe the coming “grand minimum” could be similar to the Maunder Minimum of the 17th century, when sunspot activity almost stopped – another symptom of a less active sun.
Solar wind, made up of electrically charged particles from the sun, travels at around a million miles per hour.
A reduction in solar wind would see the heliosphere – the “bubble” around the solar system maintained by particles emitted by the sun – shrink dramatically.
This protective bubble, which helps shield the earth from harmful radiation from outer space, has weakened since the 1950s.
The team has predicted a rapid reduction in its size by around the middle of this century, leaving the planet more exposed to technology-destroying solar blasts and cancer-causing cosmic radiation.
The planet’s own magnetic field deflects some of this radiation, but areas close to the north and south poles are more vulnerable where the forces are weakest.
The experts warn this could affect mobile phones and other modern gadgets.
“As the sun becomes less active, sunspots and coronal ejections will become less frequent,” said Dr Owens.
“However, if a mass ejection did hit the earth it could be even more damaging to the electronic devices on which society is now so dependent.”
The report’s co-author, Professor Mike Lockwood, added: “If the decline in sunspots continues at this rate, and data from the past suggests that it will, we could see these changes occurring as early as the next few decades.”