A country-sized hole appeared in Antarctica – and the explanation worries researchers

Scientists were stunned by satellite images of a giant polynya in East Antarctica, covering an area of about 89,000 square kilometers. A new study attributes the phenomenon to a combination of six atmospheric rivers that brought warm air and underwater heat waves that prevented the water from freezing. Researchers warn that this is a symptom of a broader trend of abnormal decline in Antarctic sea ice over the past four years.

Scientists around the world were stunned by satellite images revealing a giant polynya (open water hole) in the middle of Antarctica's frozen winter. The hole, spanning over 89,000 square kilometers – nearly the size of Portugal – was discovered in East Antarctica, in the Bay of Breid area, where ice is supposed to be stable in July and August. An international study led by Earth scientist Jibanjyoti Swain from India, published in the journal Geophysical Research Letters, found that the main cause of the phenomenon was a series of six atmospheric rivers – massive currents that carried moisture and warm air from northern regions into Antarctica. Simultaneously, strong winds caused Ekman pumping, which brought warm water from the ocean depths and created underwater heat waves that prevented the water from freezing. Researchers warn that the past four years have broken negative records for Antarctic sea ice extent, and a similar event was recently recorded in the Bellingshausen Sea, where an area of open water the size of France did not freeze. Sea ice serves as a protective belt that prevents warm ocean water from reaching the giant glaciers on land, whose melting could raise global sea levels.