The ‘weather’ 1,000 km above Earth: how it disrupts your GPS, and how scientists are fixing it

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 that acts as a highway for radio waves and lies along the path travelled by navigation satellite signals.

Changes in the density of these charged particles can delay or distort signals, affecting aircraft navigation, shipping, emergency communications and everyday location services. Understanding the ionosphere is difficult because conditions change from hour to hour and are especially hard to predict over India, which lies close to the geomagnetic equator.

Researchers at the Indian Institute of Geomagnetism, an autonomous institute under the Department of Science and Technology, addressed this by combining ground-based ionosonde observations with satellite measurements from the COSMIC radio occultation mission, reconstructing how charged-particle density actually changes with height over the Indian region rather than relying on older fixed-rate assumptions.

The research, by K Siba Kiran Guru, S Sripathi and RK Barad, was published in the journal AGU Radio Science. The improved model covers the roughly 1,000-kilometre zone where most low Earth orbit satellites operate, and researchers say it could help mission planners predict radio signal behaviour and improve navigation reliability during changing space weather.