August 19, 2011
Solar Storm Activity Likely To Start Ramping Up Within Decades
Researchers at Reading University said that solar storms are likely to become more disruptive to planes and spacecraft within decades.
The team predicts that once the Sun shifts towards an era of lower solar activity, more hazardous radiation will reach Earth.
The researchers said in Geophysical Research Letters that the Sun is currently at a grand solar maximum, which is a phase that began in the 1920s.
Mike Lockwood, professor of space environment physics at Reading, said in a statement: "All the evidence suggests that the Sun will shortly exit from a grand solar maximum that has persisted since before the start of the space age.
"In a grand solar maximum, the peaks of the 11-year sunspot cycle are larger and the average number of solar flares and associated events such as coronal mass ejections are greater.
"On the other hand in a grand solar minimum there are almost no sunspots for several decades. The last time this happened was during the Maunder Minimum, between about 1650 and 1700."
The new study indicates that most radiation hits the Earth during periods of middling solar activity. The research is based on evidence from ice cores and tree trunks going back 10,000 years.
The scientists measured levels of nitrates and cosmogenic isotopes for the study. These isotopes enter the Earth's atmosphere and are deposited in ice and organic material.
Professor Lockwood told BBC News: "You can tell by the concentration of nitrates in ice sheets that there has been a solar event. What we showed was that they all cropped up at more middling activity than we have been used to.
"We used this data to say that an unfortunate combination of solar conditions is coming our way in the next few decades.
"It's just a question of how much worse the radiation gets and how long it lasts."
A team at Stanford University in California said they have developed a technique that could give advance warning of the formation of sunspots before they become visible on the Sun's surface.
They wrote in the journal Science that their findings will help give advance warning of solar storms and the resulting radiation which disrupt communications and transport on Earth.
The team used a technique known as helioseismology to make their discovery. They found that these acoustic signals causing the vibrations moved faster in regions where sunspots were forming 40,000 miles deep.
Stathis Ilondis, head of the Stanford team, told BBC News: "It's an early warning for emerging sunspots. This is our main finding."
"We can also predict the size and strength of the sunspot. And if it is a large sunspot then it is more probable to produce some big space weather events like some strong flares."
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