The ionosphere over India has been modelled more accurately for the first time. Researchers from the Indian Institute of Geomagnetism (IIG), an autonomous body of the Department of Science and Technology (DST), combined ground‑based ionosonde data with space‑based COSMIC radio occultation measurements. This new method improves the representation of the topside ionosphere and its scale height profile.
Key Developments
- Integration of ionosonde observations with COSMIC occultation data to reconstruct electron density up to ~1000 km.
- Derivation of altitude‑dependent scale height gradient specific to the Indian region.
- Validation of the reconstructed profiles using in‑situ measurements from the Swarm satellite.
- Seasonal electron density profiles for 2014 over Tirunelveli demonstrate the model’s robustness.
Important Facts
• The electron density varies with height and time, affecting HF radio, GPS, and Indian NAVIC navigation.
• Most LEO satellites operate below 1000 km, making topside modelling essential.
• Traditional models assumed a constant topside
Exam Relevance
The study links directly to GS3 topics such as space technology, satellite navigation, and space weather. Understanding ionospheric behaviour is vital for:
- Formulating policies on space weather forecasting.
- Ensuring reliability of communication and navigation services that support defence, disaster management, and civilian sectors.
- Guiding research funding decisions for institutions like IIG and DST.
Way Forward
• Extend the methodology to other Indian longitudinal sectors and to higher latitudes.
• Incorporate real‑time data from upcoming satellite missions to provide continuous monitoring.
• Use the refined models to improve prediction of ionospheric disturbances, thereby safeguarding GPS/NAVIC accuracy and HF communication, especially during solar storms.
Overall, this breakthrough enhances India’s capability to model the near‑Earth space environment, supporting critical satellite‑based services and strengthening national resilience to space weather impacts.