Chinese icebreaker Xuelong sails in the antarctic fog. Photo: State Oceanic Administration

Chinese icebreakers and other research vessels are now on their 34th expedition to the Antarctic, and Xinhua reports that meteorologists on board these ships obtained full-depth, cross-sectional data of the Antarctic Circumpolar Current this month.

The data are believed to be vital in climate-change research.

The expedition’s lead ship, Xuelong, or “Snow Dragon” in Mandarin, a 15,000-ton, Arctic cargo ship converted into an icebreaker, is now in the middle of the westerly cyclonic areas of the ice-covered Amundsen Sea and surrounding waters in western Antarctica, racing against the clock gathering water samples and other data regarding temperature, sea-water salinity and marine organisms, before an even more frigid season seals off the entire continent.

The ice sheet that drains into the Amundsen Sea averages about 3 kilometers in thickness and is roughly the size of Myanmar.

Xuelong breaks the ice to move ahead. Photo: State Oceanic Administration

Data collected during the expedition are of high significance to the study of climate change, as the Antarctic Circumpolar Current is an important part of the global climate system and plays a vital role in the oceans’ ecological cycles of materials and energy, the Chinese Academy of Sciences and State Oceanic Administration said in a press release.

It claimed that China was the third nation after Australia and the United States to have captured the “source code” of antarctic and global climate changes.

The data also shed light on the changes in water masses and circulation that have occurred in recent decades in the Southern Ocean.

The Antarctic Circumpolar Current is the world’s biggest and the only ocean current that flows clockwise from west to east around the Antarctica. It is driven by the prevailing westerly winds.

Xuelong as seen in the Antarctic. Photo: State Oceanic Administration

Xuelong is China’s biggest polar research vessel. It started service as an icebreaking cargo and supply ship designed for the Russian Arctic and was subsequently purchased by China and converted to a polar research and resupply vessel in 1994.

It underwent massive midlife retrofits in recent years with additions of the Xueying (Snow Eagle) polar helicopter as well as an Arctic-class autonomous underwater vehicle