China's 15th scientific expedition to the Arctic Ocean concluded on Friday as the last members of the expedition team returned to Shanghai.

Carrying the mission crew, the Xuelong 2 icebreaker arrived at its home port in Shanghai on Friday morning, marking the end of China's largest-ever scientific exploration in the Arctic Ocean, according to the Ministry of Natural Resources.

The expedition was jointly carried out by four vessels — Xuelong 2, Jidi, Shenhai 1 and Tansuo 3 — and further advanced China's understanding of rapid changes in the Arctic Ocean and their impact, providing crucial support for assessing and responding to global climate change, the ministry said in a statement.

Xuelong 2 and Jidi completed tasks including comprehensive marine environmental surveys and manned deep-sea diving support. Significant progress was achieved in areas such as multidisciplinary surveys in the ice edge zone and three-dimensional coordinated observation of atmosphere-ice-ocean systems.

With the support of Xuelong 2, the Shenhai 1, carrying the Jiaolong manned submersible, achieved China's first manned deep-sea dive in Arctic ice-covered waters — a milestone reflecting the country's growing capacity to access and explore the deep sea, according to the statement.

Preliminary studies revealed major differences in benthic organism density, biodiversity and individual body size across Arctic sea areas. The findings provide support for uncovering spatial distribution patterns of polar deep-sea benthic organisms and assessing the impacts of climate change on deep-sea ecosystems, the ministry said.