Indian scientists have successfully demonstrated the endurance of autonomous ocean glider operations in the Southern Ocean, a region that plays a crucial role in global climate regulation. The Slocum G-3 glider, carried aboard the Russian research vessel MV Vasily Golovnin, was deployed during the 44th Indian Scientific Expedition to Antarctica and completed a 1,300-kilometre run between February and April last year.
The glider collected high-resolution measurements of temperature, salinity, dissolved oxygen and chlorophyll while navigating some of the harshest marine conditions on the planet. After 61 days at sea the instrument was retrieved intact during the return voyage from India’s Maitri station to Cape Town, demonstrating both reliability and resilience in extreme polar environments.
India ocean glider expands polar capability
Operated by teams from the Indian National Centre for Ocean Information Services and the National Centre for Polar and Ocean Research, Goa, the mission marked India’s first major glider deployment in Antarctic waters. ‘‘These platforms allow continuous, long-duration observations in remote areas that are difficult for conventional research vessels to sample regularly,’’ said E. Pattabhi Rama Rao, group director (Ocean Observations) at INCOIS.
The battery-powered Slocum G-3 glider moves by altering buoyancy rather than using a propeller. It can manoeuvre vertically and horizontally at roughly 8 to 10 centimetres per second, travel 20–25 kilometres a day, and dive to depths of 1,000 metres. The vehicle surfaces every five to six hours during deep missions to transmit basic data via satellite, while detailed datasets are recovered when the system is retrieved at the end of its mission life of around eight to nine months.
Before deployment, each glider is configured and ballasted at the National Glider Test Facility at INCOIS and subjected to sea trials in shallow coastal waters. The collected observations complement other monitoring systems such as tide gauges, Argo floats and fixed buoys, improving models of sea-level change, cyclonic storms and marine ecosystem health.
Officials highlight the broader significance of the Southern Ocean campaign. The region’s Polar Front, where cold Antarctic water meets warmer sub-Antarctic water, drives powerful air-sea exchanges that influence global weather patterns and carbon cycles. Continuous measurements in this zone help close critical gaps in understanding how the ocean is responding to climate change.
Buoyed by this success, INCOIS plans an ambitious follow-up: a next-generation ocean glider with enhanced battery endurance that would attempt an unprecedented meridional transect from near-shore Antarctica, close to India’s Bharati station, to the coast of Gujarat. The proposed route covers an estimated 9,800 kilometres and, if realised, would represent a first-of-its-kind long-distance mission conducted entirely by an autonomous glider.
The mission would deepen understanding of air-sea interactions across hemispheres and strengthen India’s autonomous ocean observation programme. For researchers and policymakers alike, improved observations of the Southern Ocean offer better tools to predict sea-level rise, changes to marine ecosystems and the evolution of extreme weather events.
As the country expands its fleet of buoyancy-driven platforms, this Antarctic deployment will be seen as a milestone in India’s push to enhance ocean science and operational monitoring at high latitudes.
Key Takeaways:
- India ocean glider completed a 1,300-kilometre mission across the Southern Ocean, collecting temperature, salinity, oxygen and chlorophyll data.
- The Slocum G-3 glider operated reliably in extreme polar conditions and was recovered undamaged after 61 days.
- INCOIS and NCPOR plan a next-generation glider transect of about 9,800 kilometres from near-shore Antarctica to Gujarat.
- Data will feed India’s ocean observation programme and improve climate and sea-level monitoring across hemispheres.
