Indian astronomers decode how solar storms 'cool down' on their way to Earth

IIA scientists have traced how giant solar eruptions evolve thermally across the Sun-Earth journey — insight that sharpens space-weather forecasting for the satellites, GPS, aviation and power grids these storms can disrupt.

What happened

• Astrophysicists at the Indian Institute of Astrophysics (IIA), Bengaluru — an autonomous institute under the Department of Science and Technology — uncovered how Interplanetary Coronal Mass Ejections (ICMEs) evolve thermally as they travel from the Sun to the Earth.
• ICMEs are massive blasts of magnetised plasma from the Sun's outer atmosphere; when directed at Earth, they can trigger geomagnetic storms.
• Such storms can disrupt satellite operations, GPS and radio communications, aviation routes and power grids — and produce auroras.
• Solar activity follows an ~11-year cycle; the peak of the current Cycle 25 was in 2025, increasing ICME frequency.
• Analysing three decades of solar-storm data, the team found patterns in ICMEs' thermal signatures that can improve forecasting of their geo-effectiveness and space-weather preparedness.

For Prelims

• CME / ICME: A Coronal Mass Ejection is a large expulsion of magnetised plasma from the Sun's corona; in interplanetary space it is an ICME. Earth-directed ICMEs drive geomagnetic storms.
• Space weather: Sun-driven conditions (solar flares, CMEs, solar wind) that affect satellites, GPS, HF radio, aviation (polar routes) and power grids — a growing strategic concern.
• Solar cycle: The Sun's activity waxes and wanes over an ~11-year cycle; Solar Cycle 25 peaked around 2025, raising flare/CME frequency.
• Aditya-L1: India's first solar mission (at the Sun-Earth L1 Lagrange point) studies the corona, solar wind and space weather — complementing such research.
• IIA & DST: The Indian Institute of Astrophysics (Bengaluru) is an autonomous body under the Department of Science and Technology; it operates observatories (e.g. Kodaikanal, Hanle).
• Geomagnetic storm impacts: Can cause satellite drag/anomalies, GPS errors, radio blackouts, grid-current surges (transformer damage) — hence forecasting matters.
• Don't confuse: A solar flare (electromagnetic burst) is distinct from a CME (plasma ejection); not every CME is Earth-directed, and the ICME's thermal/magnetic state determines its 'geo-effectiveness'.

For Mains

Syllabus: GS3.13 · GS1.12 · Linkage L2