SHANGHAI, Sept. 30 (Xinhua) -- China's research icebreakers Xuelong, or "Snow Dragon," and Xuelong 2 returned to Shanghai in east China on Wednesday after nearly three months of the country's 16th Arctic Ocean expedition.

The expedition successfully completed key tasks, including comprehensive investigation and monitoring, cutting-edge scientific research, and international cooperation. According to the expedition team, both the scale of the expedition and the total number of tasks reached new highs.

It achieved fruitful results in new scientific discoveries, theoretical breakthroughs, technological tests, and equipment applications, providing strong support for a deeper understanding of and effective response to global climate change and promoting sustainable development in the Arctic, said Wang Jinhui, the leader of the expedition team.

A series of new discoveries and breakthroughs made during the expedition have refreshed China's understanding of the marine environment and geophysics of the Arctic Ocean. For example, researchers found that the subsurface water in some areas of the Arctic Ocean exhibited a warming phenomenon.

During the expedition, Chinese researchers also captured some juvenile polar cod in a densely ice-covered area in the high Arctic, a discovery that may deepen scientists' understanding of the species and its habitat's ecosystem.

Through the dual-vessel operation of the Xuelong and Xuelong 2, 19 ice station operations and 95 sets of ice-based buoy deployment tasks were completed in the high-latitude waters of the Arctic Ocean in a coordinated manner, establishing a local unmanned observation array. Both the number of stations and the number of ice-based buoys deployed reached a record high, according to He Jianfeng, the chief scientist of the expedition team.

"The relevant work can not only deepen China's understanding of the rapid changes in the Arctic Ocean, improve the accuracy and level of our prediction of sea ice and ocean changes in the Arctic Ocean, but also provide valuable cross-seasonal first-hand observational data for the international governance of the Arctic Ocean's ecology," He added.

Significant breakthroughs have been achieved in the application of high-latitude communication technology. During ice station operations, the Xuelong icebreaker achieved video call and data transmission with the Qinling Station in Antarctica via its shipborne satellite internet communication equipment.

The expedition team has carried out various forms of scientific research cooperation, with seven scientists from Russia, Germany, Thailand and China's Hong Kong Special Administrative Region.

Organized by the Ministry of Natural Resources, the 16th Arctic Ocean expedition was carried out by four vessels: Xuelong, Xuelong 2, Jidi and Tansuo-3.

Jidi and Tansuo-3 are still on their research missions and are expected to return in mid-October.