Scientists unravel spotless sun mystery

Though the team has developed a crude model, they are not in a position to predict the highs and lows of the solar cycle as yet, as they are short of data to validate the model.

The data would come from two space probes – NASA’s Solar Dynamics Observatory, which was launched last year and Indian Space Research Organisation’s Aditya, which is scheduled to be launched around 2013-14.  “By 2013-14, we will have an idea about our capability to predict long-term average activity of solar frequencies. This will be useful for future space missions and for air traffic over the North Pole,” said Dibyendu Nandi, a physicist at IISc Education and Research in Kolkata.

Nandi and his colleagues from Montana State University and Harvard Smithsonian Centre for Astrophysics have explained a solar puzzle – why the Sun remained spotless for two years between 2007 and 2009, making it the longest spotless period since 1913. Sun spots are visibly dark, strongly magnetised regions on the Sun, which was first observed by Galileo Galilei in the early 17th century. Solar magnetic storms originate from sun spots, which carry vast amounts of charged particles into space. When directed towards Earth, these  particles can disrupt satellite operations, adversely impact on terrestrial telecommunication systems and pose hazard to air-traffic on polar routes. The number of sun spots changes in a cyclical manner with a periodicity of 11 years.  The last cycle that started in 1997 and peaked around 2001 remains a mystery. Using their computer model, the team provided an explanation for the long absence of the sun spots . Their findings – published in the journal “Nature”  – demonstrated how changes in the flow of plasma – the fourth state of matter – was responsible for the changes. While the study has fundamental implications, it opens up the window to predict fair weather in space.