Atmospheric rivers help create massive holes in Antarctic sea ice

Antarctica’s hot and humid air rivers play a key role in creating massive holes in sea ice in the Weddell Sea and can influence ocean conditions around the vast continent as well as climate change, according to the Rutgers co-authored research.

Scientists studied the role of long, intense plumes of warm, humid air – called atmospheric rivers – in creating huge openings in the sea ice. They focused on the Weddell Sea region in the Southern Ocean, near Antarctica, where these sea ice holes (called polynyas) rarely develop during winter. A large hole in this area was first observed in 1973 and a hole re-developed in late winter and early spring 2017.

In the first study of its kind, published in the journal Scientific advances, scientists found that strong atmospheric rivers repeated from late August to mid-September 2017 played a crucial role in the formation of the sea ice hole. These rivers brought warm, humid air from the coast South America to the polar environment, warming the surface of the sea ice and making it vulnerable to melting.

“Polynyas strongly influence the physical and ecological dynamics of the Southern Ocean,” said co-author Kyle Mattingly, post-doctoral researcher at the Rutgers Institute of Earth, Ocean, and Atmospheric Sciences. “They serve as giant ‘windows’ in sea ice that allow large amounts of heat to travel from the ocean to the atmosphere, altering regional and global ocean circulation. They also affect the timing and extent of phytoplankton (algae) blooms, which are the basis of the marine food web. Our study will pave the way for a better understanding of climate variability and change in these regions. “

Previous studies have shown that atmospheric rivers influence the melting of land ice and ice shelves in West Antarctica, and the new study builds on these findings by showing their effects on sea ice for the first time. of Antarctica. Rivers are thousands of kilometers long and sea ice holes cover thousands of square kilometers, usually at specific locations that are initiated by local ocean circulation conditions.

West Antarctica, a huge ice cap that rests on land, is melting and contributing to global sea level rise, and the melting has accelerated in the 21st century. If the entire Antarctic ice sheet melted, the ocean level would rise by about 200 feet, according to the National Snow & Ice Data Center. Rising sea levels and flooding from coastal storms threaten coastal communities around the world, especially in low-lying areas.

As part of projected future climate change, atmospheric rivers are expected to become more frequent, longer, wider, and more efficient at moving high levels of water vapor to the Antarctic Ocean and mainland, while increasing intensity. precipitation. In general, the location where they make landfall is predicted to shift towards the poles, and the effect of climate change on sea ice holes in the Weddell Sea and elsewhere in the Southern Ocean is an important area for research. future research.