A study featured in Nature Communications indicates that the interaction between meandering ocean currents and the ocean floor causes upwelling velocity that pushes warmer water to shallower depths, accelerating the melting of ice shelves in the Amundsen Sea, West Antarctica. These ice shelves are experiencing rapid destabilization, enhancing sea level rise.
The research, conducted by an international team including Taewook Park and Yoshihiro Nakayama from the Korea Polar Research Institute, Hokkaido University, and Seoul National University, employed sophisticated ocean modeling to examine forces accelerating the melt of these ice shelves. This study challenges prior theories that attributed the melting predominantly to Southern Ocean winds.
Special attention was given to the Pine Island and Thwaites ice shelves, known for their fast deterioration and vulnerability to warm ocean currents. These shelves serve as critical barriers preventing glacier flows into the ocean. Their potential collapse poses a serious threat to global coastal communities.
The research centered on the 'modified Circumpolar Deep Water,' a layer of warm water under colder surface waters. This layer's role is crucial in melting the ice shelves from below. "The flow and strength of ocean currents around the ice shelves play a decisive role in the warm water influx, significantly impacting their melting rate," explains Taewook.
Attention was also paid to the 'thermocline depth,' the boundary between deeper warm and upper cool waters. The study refutes previous beliefs that stronger westerly winds near the Amundsen Sea during El Nino episodes were primarily responsible for pushing warmer waters toward the ice shelves.
"Our findings introduce a new perspective on how internal oceanic processes might be more influential than previously thought in driving ice shelf melting," Nakayama added. "Recognizing these internal dynamics is essential as they could alter future projections significantly."
Research Report:Amundsen Sea Circulation Controls Bottom Upwelling and Antarctic Pine Island and Thwaites Ice Shelf Melting
Related Links
Hokkaido University
Beyond the Ice Age
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