30 July 2026·PIB

Scientists discover faster rotation in the Sun’s upper atmosphere

In this note

1. At a Glance

Indian researchers found that the Sun's upper atmosphere (corona) rotates faster than its visible surface (photosphere), and rotation speed increases with height above the surface — a result that challenges classical physics expectations [1].
Findings will refine space weather models, relevant to satellite operations, communication, navigation, and power-grid resilience on Earth [1].
Relevant for UPSC as a science & technology current affair tying Indian solar research institutes (ARIES, USO, PRL) to global observational data (Japan) [1].
Part of India's growing indigenous solar physics ecosystem, alongside missions like Aditya-L1 [1].

Study published in Astronomy & Astrophysics Letters (2025); publicized via PIB/DST press release dated 30 July 2026 [1].
Findings show rotation velocity of the Sun's atmosphere increases with altitude, and decreases slightly during heightened sunspot activity, a previously poorly understood behaviour [1].

The Sun's differential rotation (equator rotates faster than poles) at the photosphere level has long been established; this study extends the analysis to the upper/coronal atmosphere [1].
Related prior DST-backed work: mapping of chromospheric differential rotation using 100 years of Kodaikanal Observatory data, and identification of "magnetic trees" revealing hidden flows in the solar upper atmosphere — both from DST-affiliated institutes, indicating a sustained Indian research programme on solar rotation dynamics [1].
Present study used the 2D image-correlation method, comparing solar images across separate days to compute rotational shifts/velocity [1].

Item	Detail
Nodal Ministry	Department of Science and Technology (DST), Ministry of Science & Technology [1]
Lead institutes	ARIES (autonomous DST institute), Udaipur Solar Observatory (USO), Physical Research Laboratory (PRL), Ahmednagar College [1]
Key researchers	Srinjana Routh, Vaibhav Pant (IIT Delhi), Anshu Kumari, Jaydeep Kandekar [1]
Data source	Nobeyama Radioheliograph, Japan
Method	2D image-correlation method (day-to-day image shift analysis) [1]
Publication	Astronomy & Astrophysics Letters, 2025 [1]
Core finding	Coronal/upper-atmosphere rotation > surface rotation; speed rises with height; speed dips slightly with higher sunspot activity [1]

Scientific / Technological

Uses radio-heliograph imaging (non-Indian instrument, Japan) combined with Indian institutional analysis — reflects international data-sharing in astronomy [1].
Builds on a body of DST-funded solar studies (Kodaikanal 100-year dataset, "magnetic trees" flow study) showing a coherent national research trajectory in solar physics [1].

Economic / Strategic (Space Weather)

Better rotation models improve space weather forecasting, protecting satellites, GNSS/navigation, communications, and power grids from solar-storm-induced disruptions [1].

Administrative

Demonstrates DST's role in funding autonomous research institutes (ARIES, PRL, USO) that collaborate with academic institutions (Ahmednagar College, IIT Delhi) [1].

Historical

Extends decades-old solar differential rotation studies from the photosphere to previously less-charted atmospheric layers [1].

30 July 2026: PIB/DST press release announcing the discovery of faster upper-atmosphere solar rotation [1].
Preceding related DST releases: "Magnetic Trees help researchers unearth hidden flow in the Sun's upper atmosphere" and "Astronomers map the differential rotation of the Sun's chromosphere using 100 years of Kodaikanal data" [1].

The Sun's upper atmosphere rotates faster than its visible surface (photosphere) [1].
Rotation speed of the solar atmosphere increases with height above the surface [1].
Rotation speed decreases slightly during periods of intensified sunspot activity [1].
Study published in Astronomy & Astrophysics Letters, 2025 [1].
Data sourced from the Nobeyama Radioheliograph in Japan [1].
Method used: 2D image-correlation technique [1].
Nodal Indian institutes: ARIES, Udaipur Solar Observatory, Physical Research Laboratory, Ahmednagar College [1].
Nodal ministry: Department of Science and Technology (DST) [1].
ARIES is an autonomous institute under DST [1].
Findings aid space weather models affecting satellites, communication, navigation, and power infrastructure [1].
Related earlier DST study used 100 years of Kodaikanal Observatory data to map chromospheric differential rotation [1].
Another related DST study identified "magnetic trees" revealing hidden flow patterns in the Sun's upper atmosphere [1].

Aditya-L1 Mission (ISRO) — India's dedicated solar observation satellite, complements ground-based solar rotation studies.
Space weather and its impact on satellites/power grids — practical stakes of solar atmosphere research.
Kodaikanal Solar Observatory — source of century-long solar data used in related DST studies.
Sunspot cycle and solar maximum/minimum — links to the sunspot-activity finding in this study.
Differential rotation of the Sun — foundational astrophysics concept extended by this research.
DST autonomous institutes (ARIES, PRL, USO) — administrative/institutional science governance angle.
Coronal Mass Ejections (CMEs) and geomagnetic storms — downstream phenomena tied to solar atmospheric dynamics.

Confusing the nodal ministry: this is a DST initiative, not ISRO or MoES (Ministry of Earth Sciences) — though space-weather effects are also studied by ISRO's Aditya-L1 [1].
Mixing up photosphere (visible surface) vs corona/upper atmosphere — the surface rotates slower, not faster [1].
Assuming the observational data came from an Indian telescope — it was sourced from Japan's Nobeyama Radioheliograph [1].
Conflating this study with the separate "magnetic trees" or "Kodaikanal 100-year data" DST releases — they are related but distinct studies [1].
Misremembering the direction of the finding: rotation speed increases with height, not decreases [1].