Halo-like solar corona. Credit: NASA
Breakthrough in identifying the perplexing cause..
Researchers found a previously unknown heating mechanism that describes why the “solar corona,” the atmosphere surrounding the Sun, is much hotter than the solar surface area that emits it.
The finding at the Princeton Plasma Physics Laboratory (PPPL) of the U.S. Department of Energy (DOE) has the possible to assist fix a number of astrophysical mysteries, consisting of star formation, the source of massive electromagnetic fields in deep space, and the forecast of area weather events that can trigger cellular phone blackouts and power grid failures in the world. Understanding the heating procedure likewise has substantial ramifications for fusion energy research study.
Very first clear 3D explanation.
” Our direct mathematical simulation is the first to provide clear recognition of this heating mechanism in 3D space,” stated Chuanfei Dong, a physicist at PPPL and Princeton University who unmasked the procedure by performing 200 million hours of computer system time for the worlds biggest simulation of its kind. “Current telescope and spacecraft instruments may not have high sufficient resolution to recognize the procedure occurring at little scales,” stated Dong, who details the breakthrough in the journal Science Advances.
The surprise active ingredient is a procedure called magnetic reconnection that separates and violently reconnects electromagnetic fields in plasma, the soup of electrons and atomic nuclei that forms the solar atmosphere. Dongs simulation exposed how rapid reconnection of the magnetic field lines turns the massive unstable energy into small-sale internal energy. As an effect the turbulent energy is efficiently transformed to thermal energy at small scales, therefore superheating the corona.
Magnetic fields form thin sheets of electric present that break up due to magnetic reconnection. This procedure helps with the energy waterfall from large-scale to small, making the procedure more effective in the rough solar corona than previously believed.”.
When the reconnection process is slow while the rough waterfall is quickly, reconnection can not affect the transfer of energy throughout scales, he said. But when the reconnection rate ends up being quick enough to go beyond the standard cascade rate, reconnection can move the waterfall toward small scales more effectively.
It does this by breaking and rejoining the magnetic field lines to generate chains of little twisted lines called plasmoids. This alters the understanding of the turbulent energy waterfall that has actually been widely accepted for majority a century, the paper says. The new finding ties the energy transfer rate to how quick the plasmoids grow, enhancing the transfer of energy from large to little scales and highly warming the corona at these scales.
The new discovery demonstrates a regime with an unprecedentedly large magnetic Reynolds number as in the solar corona. The big number characterizes the brand-new high energy transfer rate of the turbulent waterfall. “The higher the magnetic Reynolds number is, the more efficient the reconnection-driven energy transfer is,” said Dong, who is relocating to Boston University to use up a professors position.
200 million hours.
” Chuanfei has performed the worlds biggest turbulence simulation of its kind that has taken control of 200 million computer CPUs [main processing systems] at the NASA Advanced Supercomputing (NAS) center,” stated PPPL physicist Amitava Bhattacharjee, a Princeton teacher of astrophysical sciences who monitored the research. “This mathematical experiment has produced undeniable evidence for the very first time of a theoretically predicted mechanism for a formerly undiscovered variety of rough energy waterfall controlled by the growth of the plasmoids.
” His paper in the high-impact journal Science Advances completes the computational program he began with his earlier 2D results released in Physical Review Letters. These papers form a coda to the impressive work that Chuanfei has done as a member of the Princeton Center for Heliophysics,” a joint Princeton and PPPL center.
The effect of this finding in astrophysical systems throughout a variety of scales can be checked out with future and current spacecraft and telescopes. Unpacking the energy transfer procedure across scales will be vital to resolving essential cosmic mysteries, the paper said.
Referral: “Reconnection-driven energy waterfall in magnetohydrodynamic turbulence” by Chuanfei Dong, Liang Wang, Yi-Min Huang, Luca Comisso, Timothy A. Sandstrom and Amitava Bhattacharjee, 7 December 2022, Science Advances.DOI: 10.1126/ sciadv.abn7627.
The research study was moneyed by the DOE Office of Science (FES) and NASA, with computer system resources provided by the NASA HEC together with the National Energy Research Scientific Computing Center, a DOE Office of Science user center, and the NSF-sponsored Computational and Information Systems Laboratory.
Dongs simulation revealed how quick reconnection of the magnetic field lines turns the massive turbulent energy into small-sale internal energy. As a repercussion the unstable energy is effectively converted to thermal energy at little scales, thus superheating the corona.
The new finding ties the energy transfer rate to how quick the plasmoids grow, enhancing the transfer of energy from big to small scales and strongly heating up the corona at these scales.
The large number defines the new high energy transfer rate of the unstable cascade. “The greater the magnetic Reynolds number is, the more efficient the reconnection-driven energy transfer is,” said Dong, who is moving to Boston University to take up a professors position.
