Magnetic Trees help researchers unearth hidden flow in the Sun’s upper atmosphere

Key Highlights:

• A study led by Aryabhatta Research Institute of Observational Sciences (ARIES) revealed the Sun's meridional flow extends into its upper atmosphere.
• This plasma flow, previously observed only in lower layers, was found nearly 3,000 km above the Sun's visible surface in the upper chromosphere.
• The research provides the first clear evidence supporting the "magnetic tree" hypothesis, linking the Sun's surface and upper layers.
• The findings enhance understanding of space weather, the solar cycle, and the solar dynamo.
• The study utilized 27 years of radio observations from the Nobeyama Radioheliograph in Japan.

Detailed Insights:

• The meridional flow is a slow, steady movement of hot gas (plasma) from the Sun's equator toward its poles.
• This flow is crucial for transporting the Sun’s magnetic fields and regulating its 11-year solar cycle.
• Researchers used a novel image-correlation technique to track tiny shifts in brightness patterns over nearly three decades.
• Plasma in the upper chromosphere was observed moving poleward at speeds of about 5 to 15 meters per second.
• The strong connection between radio features and magnetic field transport suggests structures high in the atmosphere are linked to deeper magnetic fields.
• This discovery implies the Sun's upper atmosphere is not isolated but retains information about motions occurring deep within.
• Understanding these processes is essential for predicting solar storms and space-weather events that impact Earth's technology.

Scientific/Technical Concepts Involved:

• Meridional Flow: A slow, steady movement of plasma from the Sun's equator to its poles, crucial for magnetic field transport.
• Upper Chromosphere: A layer of the Sun's atmosphere, approximately 3,000 km above the visible surface, where the extended meridional flow was discovered.
• Magnetic Tree Hypothesis: A theory proposing that magnetic structures high in the Sun's atmosphere are connected to deeper layers, similar to a tree's branches and roots.
• Solar Dynamo: The internal process within the Sun responsible for generating its magnetic field and powering its 11-year activity cycle.