Sunday 7 April 2013

Discovered: Sun's magnetic 'heartbeat'

Scientists claim to have discovered a magnetic "solar heartbeat" in the Sun's deep interior, that generates energy which leads to solar flares and sunspots.
Researchers developed a new supercomputer simulation to probe the Sun's periodic magnetic field reversals. According to the model, every 40 years the Sun's zonal magnetic field bands switch their polarity.
Scientists say that cycle is about four times longer than the 11-year sunspot cycle that governs the level of solar activity, 'SPACE.com' reported. The new study, led by the University of Montreal's Paul Charbonneau, described that modelling the Sun has been a sticky problem for decades.
The first attempts in the 1980s captured only a rough approximation of the turbulence inside of the Sun. Turbulence happens at both large and small scales. When energy from turbulence dissipates, the turbulence flows into smaller and smaller whirlpool shapes, called vortices.
On the Sun, dissipation takes place at a scale of tens of yards. That's extremely minute, compared with the huge size of the Sun, as compared to the Earth. Charbonneau said the Sun produces more dark sunspots during that time – which dim it somewhat - but it also creates small magnetic structures that brighten the surface. However, how these structures form is still under investigation.
Charbonneau and his team are examining how the magnetic field on the Sun affects the transport of energy from the inside to the outside. "There's a link between convective energy transport and the magnetic cycle, and you can measure that through going through the simulation and pulling out the flows, the primary variables," Charbonneau said.
"Once you have a magnetic cycle that builds up and develops in the simulation, you can analyze how that affects convective transport and the Sun's luminosity," he added.

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