A new model of the Sun’s solar cycle has predicted irregularities within the Sun’s 11-year heartbeat. This model, which has made the most accurate prediction ever, suggests that the solar activity will drop by 60 percent during the 2030s, which means in 15 years, Earth could start experiencing mini ice age again, or likely sink into it.
The conditions predicted by this new model have not been experienced since the last mini ice age known as the Maunder Minimum which lasted from 1645 to 1715. During this period, the sunspot activity was concentrated in the southern hemisphere of the Sun and it became exceedingly rare in the northern hemisphere.
In 1843, scientists first spotted that the Sun’s activity varies over a cycle lasting around 10 to 12 years. Since the discovery, solar physicists have been attempting to predict what each cycle will look like because every cycle is a little different and none of the models of causes to date have fully explained fluctuations – although they knew that the fluctuations were caused by a dynamo of moving fluid deep inside the sun.
Now, the team led by professor Valentina Zharkova from Northumbria University in the UK, have found that adding a second dynamo, close to the surface, creates a far more accurate model.
“We found magnetic wave components appearing in pairs, originating in two different layers in the Sun’s interior. They both have a frequency of approximately 11 years, although this frequency is slightly different, and they are offset in time. Over the cycle, the waves fluctuate between the northern and southern hemispheres of the Sun. Combining both waves together and comparing to real data for the current solar cycle, we found that our predictions showed an accuracy of 97%,” said Zharkova in a press release at Royal Astronomical Society.
The technique known as ‘principal component analysis’ of the magnetic field observations in which their new model was based on, was a complete success. For the magnetic field observations, they made use of Wilcox Solar Observatory, located in the foothills just west of the Stanford University campus.
The team examined three solar cycles-worth of magnetic field activity, from 1976 through 2008 and compared their predictions to average sunspot numbers. The magnetic wave patterns, as predicted by the model, show that there will be fewer sunspots in the next two solar cycles called Cycle 25, which peaks in 2022. Even in Cycle 26, from 2030 to 2040, there will significant reduction in solar activity as Cycle 25 because the two waves will become exactly out of synch.
“In cycle 26, the two waves exactly mirror each other – peaking at the same time but in opposite hemispheres of the Sun. Their interaction will be disruptive, or they will nearly cancel each other. We predict that this will lead to the properties of a ‘Maunder minimum’,” said Zharkova.
“Effectively, when the waves are approximately in phase, they can show strong interaction, or resonance, and we have strong solar activity. When they are out of phase, we have solar minimums. When there is full phase separation, we have the conditions last seen during the Maunder Minimum, 370 years ago,” she added.
[Images : NASA; OcelotProductions via DevianArt]