A member of China's 36th Antarctic expedition team releases a conductivity, temperature and depth measuring device on China's polar icebreaker Xuelong 2 on Jan. 15, 2020. Xuelong 2 passed through the westerlies Wednesday night local time. (Photos: Xinhua)

China's polar icebreaker Xuelong 2, or Snow Dragon 2, sails across westerlies on Jan. 15, 2020. Xuelong 2 passed through the westerlies Wednesday night local time.

China's polar icebreaker Xuelong 2, or Snow Dragon 2, sails across westerlies on Jan. 15, 2020. Xuelong 2 passed through the westerlies Wednesday night local time.

A member of China's 36th Antarctic expedition team releases a balloon on China's polar icebreaker Xuelong 2 on Jan. 15, 2020. Xuelong 2 passed through the westerlies Wednesday night local time.