Chinese icebreaker Xuelong 2 sails in the Southern Ocean during China's 36th Antarctic expedition, Jan. 11, 2020. (Xinhua/Liu Shiping)

Chinese icebreaker Xuelong 2 sails off a floating ice area in the Cosmonauts Sea and heads to travel through "roaring forties" during China's 36th Antarctic expedition, Jan. 10, 2020. (Xinhua/Liu Shiping)

Researchers on Chinese icebreaker Xuelong 2 release a weather balloon for meteorological observation during China's 36th Antarctic expedition, Jan. 11, 2020. (Xinhua/Liu Shiping)