Measurement of Turbulence Injection Scale Down to the Chromosphere

článek v časopise ve Web of Science, Jimp

en

The solar atmosphere displays a sharp temperature gradient, starting from spicules in the chromosphere at 2 x 104 K, outward into the corona exceeding 106 K. Plasma turbulence produced by the transverse motion of magnetic fields anchored in the photosphere is likely the energy source producing this gradient. However, very little is known about the turbulent structures near the solar surface. Using the highest spatial resolution white-light total solar eclipse image to date, we measure the transverse correlation length at distances ranging from 0.33 to 94 Mm above the solar surface-2 orders of magnitude closer than previous estimates. Our results show that the turbulence injection scale in the chromosphere is similar to 1.5 Mm, which we associate with the size of granules since they are the only structured features of comparable size. Further, the change in perpendicular correlation length with distance from the solar surface exhibits a plateau in the first 4 Mm, followed by a rapid increase until 9 Mm where it becomes shallower thereafter. We associate this radial gradient with the expansion of the magnetic field in the transition region between the chromosphere and the corona.

The solar atmosphere displays a sharp temperature gradient, starting from spicules in the chromosphere at 2 x 104 K, outward into the corona exceeding 106 K. Plasma turbulence produced by the transverse motion of magnetic fields anchored in the photosphere is likely the energy source producing this gradient. However, very little is known about the turbulent structures near the solar surface. Using the highest spatial resolution white-light total solar eclipse image to date, we measure the transverse correlation length at distances ranging from 0.33 to 94 Mm above the solar surface-2 orders of magnitude closer than previous estimates. Our results show that the turbulence injection scale in the chromosphere is similar to 1.5 Mm, which we associate with the size of granules since they are the only structured features of comparable size. Further, the change in perpendicular correlation length with distance from the solar surface exhibits a plateau in the first 4 Mm, followed by a rapid increase until 9 Mm where it becomes shallower thereafter. We associate this radial gradient with the expansion of the magnetic field in the transition region between the chromosphere and the corona.

ENERGY-CONTAINING EDDIES; ELECTRON HEATING RATES; SOLAR-WIND; TRANSITION REGION; ALFVEN WAVES; MAGNETOHYDRODYNAMIC TURBULENCE; CORONA; PROTON; GRANULATION; EVOLUTION

20.02.2025

IOP Publishing Ltd

BRISTOL

2041-8213

980

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