The energy flow in astrophysical plasmas is revealed through the largest turbulence simulation ever performed
The solar corona can be vastly hotter than the solar surface, thanks to a previously hidden heating process. There was a discovery at the U. S. The ability to predict eruptive space weather events, the origin of large-scale magnetic fields in the universe, and the ability to tackle a range of astrophysical puzzles could be improved by the Department of Energy. Understanding the heating process has implications for fusion research.
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First clear 3D explanation
"Our direct numerical simulation is the first to provide clear identification of this heating mechanism in 3D space," said Chuanfei Dong, a physicist at PPPL and Princeton University who unmasked the process by conducting 200 million hours of computer time for the world's largest simulation of its kind h1
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According to the journal Science Advances, current telescope and spacecraft instruments may not have high enough resolution to identify the process occurring at small scales. The solar atmosphere is formed by a soup of electrons and atomic nuclei that are separated by a process called magnetic reconnection. The simulation showed how the magnetic field lines turn large-scale turbulent energy into small-sale internal energy. The corona is superheated because the turbulent energy is converted to thermal energy at small scales.
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Think of putting cream in coffee. The drops of cream become whorls. Thin sheets of electric current break up due to magnetic reconnection. The process facilitates the energy cascade from large-scale to small-scale, making it more efficient in the turbulent solar corona. The transfer of energy can't be affected when the reconnection process is slow. When the reconnection rate is fast enough to surpass the traditional cascade rate, it can move the cascade toward small scales more efficiently. The plasmoids are created by breaking and rejoining the magnetic field lines. The paper says that this changes the understanding of the turbulent energy cascade that has been accepted for more than half a century.
The energy transfer rate is tied to how fast the plasmoids grow, enhancing the transfer of energy from large to small scales and heating the corona at these scales. The solar corona has a large magnetic Reynolds number. The new high energy transfer rate is characterized by a large number. The more efficient the reconnection-driven energy transfer is, the higher the magnetic Reynolds number is.
200 million hours
"Chuanfei has carried out the world's largest turbulence simulation of its kind that has taken over 200 million computer CPUs at the NASA Advanced Supercomputing (NAS) facility," said PPPL physicist Amitava Bhattacharjee, a Princeton professor of astrophysical sciences who supervised the research h1
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This numerical experiment has produced irrefutable evidence for the first time of a theoretically predicted mechanism for a previously undiscovered range of turbulent energy cascade 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.
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The papers form a coda to the work that Chuanfei has done as a member of the center. The NASA High-End Computing program gave us generous allocation of computer time, and we are grateful for that. The impact of this finding can be explored with current and future telescopes. The paper said thatpacking the energy transfer process across scales will be crucial to solving key Cosmic mysteries.