Sun's Upper Atmosphere Rotates Faster than its Surface

PRERNA FOR IAS

Mehnat Aapki, Guidance Humari

Roz ki Prelims Practice — Experts ke Saath

Sun's Upper Atmosphere Rotates Faster than its Surface

Background

A recent study by Indian scientists has revealed that the Sun's upper atmosphere rotates significantly faster than its visible surface (Photosphere). This remarkable finding challenges the traditional understanding of the rotational behaviour of gaseous celestial bodies and provides new insights into solar physics. The research was carried out by scientists from institutions supported by the Department of Science and Technology (DST), Government of India, and has been published in the prestigious journal Astronomy & Astrophysics Letters.

Salient Findings

The study found that the Sun's rotation rate increases with altitude, contrary to the classical expectation that rotational speed should decrease away from the surface due to the conservation of angular momentum. Researchers also observed that during periods of high solar activity, when the number of sunspots increases, the rapid rotation of the upper atmosphere slows slightly.

The analysis was based on high-quality radio observations obtained from Japan's Nobeyama Radioheliograph. Scientists used an advanced 2D image-correlation technique to compare solar images captured on different days and accurately measure the displacement of solar features.

Significance

The discovery improves our understanding of the solar dynamo, the process responsible for generating the Sun's magnetic field. It will help scientists develop more accurate space weather forecasting models, enabling better prediction of solar flares and geomagnetic storms.

Improved forecasts are important because severe space weather can disrupt satellites, GPS navigation, radio communication, aviation systems, and power grids. The findings will also enhance the interpretation of data from India's Aditya-L1 mission and support future solar research.

India's Contribution

The study highlights India's growing capabilities in solar physics and space science through collaboration among ARIES (Nainital), Udaipur Solar Observatory–Physical Research Laboratory (USO-PRL), Ahmednagar College, and other research institutions under the Department of Science and Technology (DST).

Current Status

The findings have been published in Astronomy & Astrophysics Letters and are expected to refine existing models of solar rotation and magnetic field generation. The research represents an important step towards improving space weather prediction and strengthening India's role in advanced solar and space research.

Analytical Questions

Question 1. This discovery appears to challenge a classical physics expectation. As a civil servant, how would you explain this without creating the impression that scientific laws are wrong?

Answer: Scientific laws are based on the best available evidence. When new observations do not fully match existing models, scientists improve their understanding instead of rejecting science. This discovery encourages deeper research into the Sun's behaviour. It shows that science grows through observation, testing and continuous refinement of theories.

Question 2. Why should a district administrator or policymaker be interested in research on the Sun's upper atmosphere, which seems unrelated to day-to-day governance?

Answer: Space weather affects communication, navigation, electricity and disaster response systems. Better forecasts help protect satellites, GPS services, aviation and power grids. Administrators depend on these systems during emergencies. Therefore, advances in solar research indirectly improve governance, public safety and economic resilience even at the local level.

Question 3. The study used international data but was led by Indian scientists. What does this tell us about the nature of modern scientific research?

Answer: Today's science is based on collaboration rather than competition alone. Countries share data, instruments and expertise to solve complex problems. India contributes through skilled researchers, analysis and innovation while using global scientific facilities. Such partnerships improve knowledge, strengthen diplomacy and increase the quality and credibility of research.

Question 4. How can this discovery strengthen India's space programme beyond improving scientific knowledge?

Answer: Better understanding of solar behaviour improves space weather prediction. This helps protect satellites, supports safer space missions and improves the analysis of data from missions like Aditya-L1. Stronger scientific capability also builds confidence in Indian research institutions and supports future innovation in space technology and national security.

Question 5. If future observations again contradict current models of solar rotation, should scientists change their theories immediately? Why or why not?

Answer: No. One observation alone is rarely enough to change scientific understanding. Scientists first verify the data, repeat experiments and compare independent results. If strong evidence continues to support the new finding, theories are revised. Careful verification keeps science reliable while allowing genuine discoveries to improve existing knowledge.