【学术报告】 ～～～～～～～～～～～～～～～～Report Title: Face-to-Face with the Sun's Black Subsurface Magnetic Field Horizontal Oscillations and High Energy Output

Speaker: Prof. Yuan Ding (Ph.D., Professor, Doctoral Supervisor)

Institution: Harbin Institute of Technology (Shenzhen)

Language: Chinese

Date & Time: 2023-05-30, Tuesday, 11:00 am - 12:00 pm

Location: Room 502, Building No.1

Abstract:

The current two heating mechanisms for the solar corona—magnetic reconnection and magneto-acoustic wave heating—both face different challenges in addressing the issue of coronal heating. While magnetic reconnection has a small spatial scale and short temporal scale that is difficult for existing large ground-based telescopes to resolve; magneto-acoustic waves have a larger spatial scale and longer temporal scale that can be effectively observed by these telescopes. However, various wave modes either carry too little energy or release it at too low a frequency to meet the energy requirements for coronal heating.

This study employs the Goode Solar Telescope at Big Bear Solar Observatory to observe horizontal oscillations in black sunspot penumbrae for the first time. These oscillations induce horizontal magnetic field oscillations with long durations and negligible decay. Calculating this energy flux using magnetohydrodynamic theory reveals an astonishing value of 7.52 × 10^6 W m^-2; even just a tiny fraction of this amount would satisfy coronal heating needs.

Numerical simulations based on double-fluid magnetohydrodynamics show that most of this energy dissipates through collisions between neutral particles and ions in chromosphere layers via friction effects, resulting in significant heat generation.

This research uses both large ground-based telescopes and numerical simulations to detect persistent high-intensity energy sources within black sunspot shadow regions; it holds promise for advancing our understanding of coronal heating issues and serves as an important observational target for large ground-based telescopes.

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Inviting Team Members:

FASOT Research Team & Yunnan Astronomical Society Promotion Committee

Contact Person(s): Mr. Qu Zhongquan & Ms. Deng Linhua

May 26th