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New way to predict space weather

20110818 X-class solar flare-full

Using helioseismology to watch for sunspots will help people prepare for events such as the powerful X-class solar flare which burst from a sunspot region on the 9th of August, 2011 (Source: NASA/ Solar Dynamics Observatory )


The new research will improve astronomers' ability to forecast space weather events which can damage terrestrial power grids, communications and navigation systems, and pose hazards to spacecraft and astronauts.

The work by scientists including Stathis Ilonidis from California's Stanford University uses doppler observations from the Solar and Heliospheric Observatory spacecraft (SOHO), which monitors the Sun continuously.

Scientists use helioseismology to study the Sun's internal structure. Ilonidis and colleagues used the technique to detect subsurface signatures and anomalies, allowing them to monitor magnetic structures deep inside the Sun.

They found the perturbations, which were generated 65,000 kilometres below the surface, were far stronger than previous models had predicted.

Reporting in the journal Science, Ilonidis and colleagues say these magnetic structures rise from the Sun's interior at speeds of up to 600 metres per second, erupting as sunspots on the surface a day or two later.

They say the technique of imaging the deep solar interior, combined with observations from other spacecraft such as the Solar Dynamics Observatory will allow them to detect large sunspot regions before they appear on the surface.

Sunspots can generate high energy solar flares and coronal mass ejections, which are powerful blasts of magnetically charged plasma particles.

These can fling intense radiation at very high speeds towards Earth resulting in damaging space weather events.

Dr David Neudegg from the Australian Ionospheric Prediction Service which monitors space weather, says the technique could also provide a deeper insight into the nature of sunspots.

"At the moment we're only seeing the surface. Once we can get underneath, it becomes easier to understand why it all happens" says Neudegg.

He points out that scientists have been applying helioseismology to monitor events on the Sun's far side for a while.

"But not all sunspots emerge on the far side", says Neudegg.

"From an operational space weather point of view, any advanced warning of active regions is useful."

Tags: physics, stars