Sun’s Upper Atmosphere And Magnetic Tree Hypothesis

Source: PIB
GS III: Science & Technology

Overview

1. News in Brief
2. Key Highlights
3. Significance for India

Why in the News?

Scientists from Aryabhata Research Institute of Observational Sciences (ARIES) and international collaborators have discovered that the Sun’s meridional (poleward) plasma flow extends into the upper chromosphere.

News in Brief

• The study provides the first strong observational evidence supporting the long-standing Magnetic Tree hypothesis, linking the Sun’s surface with its upper atmosphere.
• The findings improve understanding of the solar dynamo, magnetic field evolution, and the Sun’s 11-year solar activity cycle.
• The research is expected to enhance space weather forecasting, helping protect satellites, navigation systems, communication networks, and power grids from solar disturbances.

Key Highlights

• Hidden Plasma Flow
  • The Sun has a slow meridional (poleward) flow that transports plasma and magnetic fields from the equator toward the poles.
  • The study shows this flow extends well beyond the lower atmosphere into the upper chromosphere.
• Magnetic Tree Hypothesis
  • The new observations provide strong evidence supporting Magnetic Tree Hypothesis.
  • The concept proposes proposes that magnetic structures extending high above the Sun’s surface are connected to deeper layers in the same way that the branches of a tree remain connected to its trunk and roots.
• Research Method
  • Scientists analysed 27 years of radio observations from Japan’s Nobeyama Radioheliograph.
  • A novel image-correlation technique tracked brightness shifts to map large-scale plasma movement.
• Major Findings
  • Plasma in the upper chromosphere moves toward the poles at speeds of about 5 to 15 metres per second, similar to the speeds measured in deeper layers of the Sun.
  • Magnetic structures observed high in the atmosphere closely follow the Sun’s magnetic field migration.
  • Northern and southern hemispheres may exhibit different flow behaviour depending on magnetic activity.
• Importance
  • Improves understanding of how plasma and magnetic fields move through the Sun is essential because these processes drive solar activity and influence solar storms and other space-weather events.
  • Helps explain the Sun’s 11-year solar cycle.
  • Supports better prediction of solar storms affecting satellites, GPS, communication systems and power grids.

Significance for India

• Strengthens India’s capabilities in solar physics and space science.
• Improves forecasting of space weather affecting ISRO missions and satellite services.
• Supports reliable communication, navigation and power infrastructure.
• Enhances international scientific collaboration.

Conclusion

The discovery of plasma flow extending into the Sun’s upper chromosphere marks a significant advance in solar physics by strengthening our understanding of the Sun’s magnetic field and activity cycle. It will improve space weather forecasting, enhance the resilience of critical infrastructure, and support future space exploration and satellite-based services.

Key Takeaways

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UPSC Prelims and Mains Practice Questions

Consider the following statements regarding the recent “Magnetic Tree” study of the Sun:

1. The study found that the Sun’s meridional flow extends into the upper chromosphere.
2. Plasma is an electrically neutral gas with no charged particles.
3. The solar dynamo is responsible for generating the Sun’s magnetic field.

Which of the statements given above is/are correct?

(a) 1 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

Answer: (b)

Mains Practice Question

Q. “Understanding the Sun’s magnetic field is essential for improving space weather forecasting. Discuss the significance of recent discoveries on plasma flow in the Sun’s upper atmosphere for science, technology and India’s space programme.” (150 Words)

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