According to a new study, in the next few decades, the Sun might enter an extremely quiet phase like we haven’t seen since the beginning of the 1700s.
The research, published in Scientific Reports, estimates the variation in solar wind and activity based on sunspot observations over the last 400 years. The intensity of the solar wind depends on the activity of the Sun and sunspots are a good proxy for it. The more active the Sun is, the more sunspots we can see.
The team took particular interest in the activity for the Maunder Minimum, a period between 1645 and 1715, when the Sun was particularly inactive.
“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,” lead author Dr Mathew Owens, from the University of Reading’s Meteorology Department, said in a statement. “As the Sun becomes less active, sunspots and coronal ejections will become less frequent. 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 magnetosphere is a bubble of charged particles surrounding Earth created by the solar wind and the magnetic field of our planet. As the Sun goes through its cycles, the magnetosphere responds accordingly. A reduction in solar wind would shrink the magnetosphere and it might not be able to shield us from an intense geomagnetic storm.
A side effect of this is that it will be difficult to see the Northern Lights at low latitudes, for example in the UK, by the middle of this century. "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," Dr Owens added.
Less solar wind could also shrink the heliosphere, the large region of plasma that extends from the Sun all the way beyond Pluto, by one-third. This bubble helps deflect high energy cosmic rays that are produced by supernovae and other extreme events.
“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,” added co-author Professor Mike Lockwood, also from the University of Reading.
There’s a lot of interest in the Maunder Minimum and how solar activity impacts Earth’s climate.
“The Maunder Minimum in solar activity of the 17th century is sometimes mistakenly thought to be the cause of the so-called Little Ice Age, when winter temperatures in Europe, and elsewhere in the world, were lower than average,” continued Professor Lockwood. “But the Little Ice Age began before the Maunder Minimum and ended after it, and our previous work with the Met Office has shown that the coming solar minimum will do little to offset the far more significant global heating effects of greenhouse gas emissions.”