Mystery Sea Opened Up During the Antarctic Winter. Now, Scientists Know Why.

A polynya in Antarctica’s Weddell Sea.

Credit: Wolfgang Kaehler/LightRocket through Getty Images

A swath of ice-free sea that routinely opens throughout the freezing Antarctic winter seasons is produced by cyclones.

Sea ice in Antarctica is thickest in the winter season, so the look of open water is difficult. These ocean blues are called polynyas. In 2017, researchers found one in the Lazarev Sea, which they called the Maud Increase polynya since it sits over an ocean plateau called Maud Increase.

Now, scientists led by Diana Francis, a New York City University Abu Dhabi climatic researcher, discover that cyclonic winds press ice in opposite instructions, triggering the pack to open and expose ocean blue. [Antarctica: The Ice-Covered Bottom of the World (Photos)]

In mid-September 2017, the Maud Increase polynya was 3,668 square miles (9,500 square kilometers) in size. By mid-October, it had actually grown to 308,881 square miles (800,000 square km).

The Maud Rise polynya in September 2017.

The Maud Increase polynya in September 2017.

Credit: NASA Worldview

An analysis of high-resolution satellite images discussed the fast development. Warm, wet air streaming in from the western South Atlantic struck cold air headed northward from the south, setting the phase for storms. The resulting cyclones ranked 11 on the Beaufort storm scale, implying they included wind speeds of approximately 72 miles per hour (117 km/h) and waves approximately 52 feet (16 meters) high anywhere they came across ocean blue.

These swirling winds pressed ice far from the cyclonic centers, Francis and her coworkers composed April 24 in the journal JGR Environments

Polynyas aren’t brand-new or always damaging. According to the National Snow and Ice Data Center (NSIDC), they can offer crucial ocean gain access to for Antarctic animals and environment for phytoplankton

Nevertheless, polynyas might alter in a warming future, Francis and her coworkers hypothesized. Antarctica is anticipated to experience more powerful cyclones as the environment modifications, since designs reveal that storms are most likely to form more frequently towards the poles and to be more extreme, according to the NSIDC.

If those forecasts are proper, Antarctica may see more open water in future winter seasons.

Initially released on Live Science