The study, published in the journal Science Advances on August 12, was conducted by researchers at Caltech and the Jet Propulsion Laboratory. It is based on a model representing a narrow ocean current, which runs along the coast of Antarctica. Current flow patterns show how freshwater, which has melted from ice shelves, can trap dense warm ocean water at the base of the ice, intensifying the heat and thereby causing more ice to melt. “If this mechanism we are studying is active in the real world, it could mean that ice melt rates are 20 to 40 percent higher than predicted in global climate models, which typically cannot simulate these strong currents near Antarctic coasts. Andy Thompson, one of the researchers and a professor of environmental science and engineering, said in a Caltech news release. According to the announcement, “ice shelves are outcrops of the Antarctic ice sheet, located where ice is pushed off the land and floats to the top of the ocean.” Several hundreds of meters thick, the shelves provide a protective buffer for the mainland ice, preventing the entire ice sheet from flowing into the ocean. “A warming atmosphere and warming oceans caused by climate change are increasing the rate at which these ice shelves are melting,” the press release states, which “threatens their ability to contain the flow of the ice sheet.” The study was led by senior researcher Mar Flexas, who said their climate model assessed a current often overlooked by other researchers: the Antarctic Coastal Current, which runs counter-clockwise across the Antarctic continent and is often considered too small to provide relative data. “Major global climate models do not include this coastal current because it is very narrow — only about 20 kilometers wide, while most climate models only capture currents 100 kilometers wide or larger,” Flexas said in the release. “So there is a possibility that these models may not represent future melting rates very accurately.” The increased melting of waters could escalate melting on the West Antarctic ice shelves thousands of kilometers away from the peninsula, research suggests. The release states that “this remote warming mechanism may be part of the reason that volume loss from the West Antarctic ice shelves has accelerated in recent decades.” “There are aspects of the climate system that we are still discovering,” Thompson said in the release. “As we have made progress in our ability to model the interactions between the ocean, the ice shelves and the atmosphere, we are able to make more accurate predictions with better bounds on uncertainty. We may need to rethink some of the sea level predictions.” rise over the next decades or century—that’s the work we’ll be doing in the future.”
