Supercomputer simulations provide a better picture of the sun’s magnetic field

The sun’s robust, dynamic magnetic subject can catapult big jets of plasma often known as coronal mass ejections (CMEs) out into the solar system. Generally these hit Earth, the place they’ll knock out energy grids and harm satellites.

Scientists do not totally perceive how magnetic fields are generated and amplified contained in the sun, however a examine not too long ago printed in Nature Astronomy solutions one of many basic questions on this advanced course of. By clarifying the dynamics behind solar climate, these findings may assist predict main solar occasions a number of days earlier, offering important further time for us to organize.

The sun’s magnetism comes from a course of often known as the solar dynamo. It consists of two fundamental components, the large-scale dynamo and the small-scale dynamo, neither of which scientists have been capable of totally mannequin but. In actual fact, scientists aren’t even certain whether or not a small-scale dynamo may exist within the circumstances discovered within the sun. Addressing that uncertainty is essential, as a result of a small-scale dynamo would have a big impact on solar dynamics.

Within the new examine, scientists at Aalto College and the Max Planck Institute for Photo voltaic System Analysis (MPS) tackled the small-scale dynamo query by operating large pc simulations on petascale supercomputers in Finland and Germany. The joint computing energy enabled the staff to straight simulate whether or not the sun may have a small-scale dynamo.

“Utilizing one of many largest doable computing simulations presently obtainable, we achieved probably the most real looking setting up to now through which to mannequin this dynamo,” says Maarit Korpi-Lagg, astroinformatics group chief and affiliate professor at Aalto College’s Division of Pc Science. “We confirmed not solely that the small-scale dynamo exists but additionally that it turns into extra possible as our mannequin extra intently resembles the sun.”

Some earlier research have urged that the small-scale dynamo won’t work underneath the circumstances present in stars just like the sun, which have a really low magnetic Prandtl quantity (PrM), a measure utilized in fluid and plasma physics to match how shortly variations within the magnetic subject and velocities even out. Korpi-Lagg’s analysis staff modeled circumstances of turbulence with unprecedentedly low PrM values and located that, opposite to what has been thought, a small-scale dynamo can happen at such low values.

“It is a main step in direction of understanding magnetic field era within the sun and different stars,” says Jörn Warnecke, a senior postdoctoral researcher at MPS. “This outcome will carry us nearer to resolving the riddle of CME formation, which is essential for devising safety for the Earth towards hazardous space climate.”

The analysis group is presently increasing their examine to even decrease magnetic Prandtl quantity values utilizing GPU-accelerated code on the brand new pan-European pre-exascale supercomputer LUMI. Subsequent, they plan to review the interplay of the small-scale dynamo with the large-scale dynamo, which is answerable for the 11-year solar cycle.