China completes 1st manned dive under Arctic ice in historic polar expedition

China's research icebreaker Xuelong 2 returned to Shanghai on Friday, marking the successful completion of China's 15th Arctic Ocean Scientific Expedition. 

Organized by the Ministry of Natural Resources, this comprehensive mission stands as the country's largest Arctic expedition to date, coordinating four research vessels – Xuelong-2, Jidi, Shenhai-1 and Tansuo-3 – to carry out key national research and development tasks. The expedition has significantly advanced China's understanding of the rapidly changing Arctic environment and its global climate implications.

During the mission, icebreaker Xuelong-2 and Jidi, focused on the Chukchi Plateau, the Canada Basin and the central Arctic Ocean, carrying out comprehensive marine environmental surveys and supporting manned deep-diving operations. Major progress was made in multidisciplinary studies of the ice marginal zone and integrated atmosphere-ice-ocean observation.

The mission advanced synchronous observation capabilities through dual-ship operations in high-latitude waters, filling critical data gaps and enhancing the accuracy of marine environmental forecasting. It also conducted long-term sea ice monitoring, using quasi-real-time tracking of ice drift and sub-ice hydrological and ecological changes to reveal key seasonal dynamics within the Arctic's multi-layered systems.

Furthermore, the expedition enabled advanced ecological research: multi-depth benthic imaging systems captured multidimensional, multi-temporal data from the ice marginal zone, while repeated observations of subsurface chlorophyll maxima shed light on the formation of "marine snow" and ecosystem responses to sea-ice retreat.

In a landmark achievement for China's deep-sea capabilities, the submersible Jiaolong, supported by its mother ship Shenhai-1 and aided by Xuelong-2, completed the country's first manned dive under Arctic ice. This demonstrates China's growing expertise in deep-sea exploration under extreme conditions.

Preliminary findings from the dives revealed significant spatial variations in the density, biodiversity and size of benthic organisms across spans of tens to hundreds of kilometers. These discoveries provide valuable support for understanding the distribution of polar deep-sea benthos and assessing the impacts of climate change on abyssal ecosystems.

The expedition has substantially strengthened China's scientific foundation for understanding rapid Arctic changes. The data and outcomes are expected to contribute critical support to global efforts in understanding and responding to climate change.