Context

Astronomers from the Indian Institute of Astrophysics (IIA) recently used 11 years of Ca-K line spectroscopic data (2015–2025) from the Kodaikanal Solar Observatory to map solar magnetic activity across latitudes.

Importance of Studying Solar Magnetic Activity:

• • • The Sun undergoes 11-year solar cycles, with variations in magnetic activity.
    • Solar disturbances affect Earth by:
      • Disrupting satellite communication
      • Affecting GPS and navigation
      • Damaging power grids
      • Influencing climate and atmospheric patterns
    • Mapping magnetic activity helps predict space weather, crucial for India’s increasing space-based infrastructure.

Key Findings of the Study:

Most solar activity is concentrated between 40° north and south latitudes, with strongest activity around 15–20° in both hemispheres.

  Hemispheric differences:

·         The southern hemisphere shows steeper increases in activity at higher latitudes.

·         Clear north–south asymmetries in magnetic activity were observed.

Spectral response profiles correlated with magnetic filling factor and sunspot activity, confirming large-scale patterns in solar magnetic evolution.

The study tracked changes from the peak of solar cycle 24 to the peak of solar cycle 25, showing predictable patterns in the 11-year solar cycle.

Significance for Science and Technology:

1.      Better Understanding of the Solar Dynamo

·         Patterns observed help decode:

o    Temperature variations

o    Magnetic field strength variations

o    Evolution of magnetic features across the chromosphere

2.      Improved Space Weather Prediction

·         Helps forecast:

o    Solar storms

o    Coronal mass ejections (CMEs)

o    Radio blackouts

·         Crucial for ISRO satellites, communication networks, aviation, and defence systems.

3.      Potential Applications

• • • Planning satellite launches during quiet solar periods
    • Protecting power grids with early warning
    • Designing radiation-hardened space electronics

Relevance for India:

• • India’s growing satellite fleet, digital communication reliance, and power grid vulnerability make solar weather monitoring essential.
  • Strengthens India’s capabilities in:
    • Space situational awareness
    • Solar physics research
    • Indigenous scientific instrumentation

Conclusion:

The Kodaikanal Solar Observatory’s long-term Ca-K line data and innovative latitude-band technique have provided deeper insights into how solar magnetic activity evolves across latitudes. These findings are vital for enhancing India’s space weather forecasting capability, protecting satellites and communication infrastructure, and strengthening scientific understanding of the Sun’s magnetic dynamo.