Bengaluru: When we think of weather, we usually picture clouds, rain or heat. But hundreds of kilometres above Earth, another kind of weather is constantly unfolding. Invisible disturbances in the upper atmosphere can bend radio signals, disrupt satellite communications and reduce the accuracy of navigation systems such as GPS on Earth.A team of Indian scientists has now found a better way to monitor this region over India, potentially making satellite operations, navigation and communication services more reliable.The study focuses on the ionosphere, a layer of Earth’s upper atmosphere filled with electrically charged particles. This region acts as a highway for radio waves, allowing long-distance communication by reflecting some signals back to Earth. It also lies along the path travelled by signals from navigation satellites.Changes in the density of charged particles can delay or distort those signals, affecting everything from aircraft navigation and shipping to emergency communications and everyday location services. Understanding the ionosphere, however, is not straightforward. Conditions change from hour to hour and are especially difficult to predict over India because the country lies close to the geomagnetic equator, where the movement of charged particles is particularly complex.Older models typically assumed this layer thins out at a fixed, steady rate with height — a simplification made largely because reliable real-world data was scarce. In reality, that rate varies significantly, especially near the equator, which meant existing models often drifted from what was actually happening overhead.“Researchers at the Indian Institute of Geomagnetism (IIG), an autonomous institute under the Department of Science and Technology (DST), tackled this problem by combining observations from ground-based ionosondes with satellite measurements from the COSMIC radio occultation mission. Instead of relying on that fixed assumption, their method reconstructs how charged-particle density actually changes with height over the Indian region — offering a far more realistic picture,” DST said.The improvement matters because most low Earth orbit satellites, including many used for communication and Earth observation, operate within roughly 1,000 kilometres of Earth, precisely the zone this new model captures more accurately.Better models here can help mission planners predict how radio signals will behave, improve satellite tracking, and make navigation systems more dependable during changing space weather. The research was carried out by K Siba Kiran Guru, S Sripathi and RK Barad, and published in the journal AGU Radio Science.The study provides improved estimates of how the upper ionosphere behaves over India and could be adapted for other parts of the world. The researchers say the approach could strengthen regional space weather prediction and improve the reliability of communication and navigation systems that millions depend on every day.
