WNAM REPORT: China’s 41st Antarctic expedition has successfully completed a pivotal survey of the Amundsen Sea and Ross Sea, uncovering rare instances of polynyas. These are vital open-water regions within sea ice that influence both Antarctica’s ecology and global climate patterns.
Sun Yongming, a member of China’s 41st Antarctic expedition, explained the visualization of sea ice concentrations and the significance of polynyas along the coast.
“This map shows the average sea ice concentration from 2013 to 2020. It reflects data for November, with yellow areas indicating 100 percent ice coverage and pure blue areas representing 0 percent, or open water. Along the coast, you can see the blue water surface, which we call polynyas,” said Sun.
Polynyas form through various natural processes. Sun explained that the most common method involves Antarctica’s katabatic winds – strong, downward winds that push newly formed sea ice away from the coast, creating open water areas. This phenomenon, known as a wind-driven polynya, fluctuates in size over time, depending on changing weather patterns.
“In extremely low temperatures, it’s only these polynyas that produce new ice. Once new ice forms, it gets blown outward by the wind, and more ice continues to form, so we refer to this process as an ‘ice factory.’ We typically measure a polynya’s size by the amount of ice it produces. The Amundsen Sea polynya is currently the fourth largest among all the polynyas around Antarctica; it’s quite substantial,” Sun added.
More than a dozen large polynyas exist around Antarctica, with the Amundsen Sea polynya being one of the largest and most significant. These areas play a key role in the region’s heat exchange, supporting higher biological productivity and offering unique insights into the dynamics of Antarctica’s ecosystem.
“Polynyas facilitate heat exchange, which creates a more favorable environment for biological activity. Studies show that the Amundsen Sea polynya has the highest primary productivity of all the polynyas around Antarctica. That’s why we’re particularly focused on understanding how polynyas impact the entire ecosystem, which is why we’ve been conducting extensive ecological observations in the area,” Sun concluded.
China’s 41st Antarctic Expedition set sail from the southern Chinese port city of Guangzhou on November 1, 2024, with three vessels: the Xuelong and Xuelong-2 for scientific research and logistics, and the “Yongsheng” cargo ship, which is supplying materials for the Qinling Station. The mission is set to last nearly seven months, with a return scheduled for May 2025.
