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arXiv · 2308.10982

Fleeting Small-scale Surface Magnetic Fields Build the Quiet-Sun Corona

L. P. Chitta·S. K. Solanki·J. C. del Toro Iniesta·J. Woch·D. Calchetti·A. Gandorfer·J. Hirzberger·F. Kahil·G. Valori·D. Orozco Suárez·H. Strecker·T. Appourchaux·R. Volkmer·H. Peter·S. Mandal·R. Aznar Cuadrado·L. Teriaca·U. Schühle·D. Berghmans·C. Verbeeck·A. N. Zhukov·E. R. Priest
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Abstract

Arch-like loop structures filled with million Kelvin hot plasma form the building blocks of the quiet-Sun corona. Both high-resolution observations and magnetoconvection simulations show the ubiquitous presence of magnetic fields on the solar surface on small spatial scales of $\sim$100\,km. However, the question of how exactly these quiet-Sun coronal loops originate from the photosphere and how the magnetic energy from the surface is channeled to heat the overlying atmosphere is a long-standing puzzle. Here we report high-resolution photospheric magnetic field and coronal data acquired during the second science perihelion of Solar Orbiter that reveal a highly dynamic magnetic landscape underlying the observed quiet-Sun corona. We found that coronal loops often connect to surface regions that harbor fleeting weaker, mixed-polarity magnetic field patches structured on small spatial scales, and that coronal disturbances could emerge from these areas. We suggest that weaker magnetic fields with fluxes as low as $10^{15}$\,Mx and/or those that evolve on timescales less than 5\,minutes, are crucial to understand the coronal structuring and dynamics.

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L. P. Chitta, S. K. Solanki, J. C. del Toro Iniesta, J. Woch, D. Calchetti, A. Gandorfer, J. Hirzberger, F. Kahil, G. Valori, D. Orozco Suárez, H. Strecker, T. Appourchaux, R. Volkmer, H. Peter, S. Mandal, R. Aznar Cuadrado, L. Teriaca, U. Schühle, D. Berghmans, C. Verbeeck, A. N. Zhukov, E. R. Priest. 2023-08-21. Fleeting Small-scale Surface Magnetic Fields Build the Quiet-Sun Corona. https://doi.org/10.3847/2041-8213%2Facf136

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