New analysis indicates that local weather conditions, not continental winds as previously thought, could be driving the rapid retreat of the Pine Island Glacier, the fastest melting glacier in Antarctica.
Scientists from the University of East Anglia used records between 2009 and 2014 to determine how local atmospheric conditions are directly affecting the ocean conditions that are rapidly melting the Pine Island Ice Shelf, part of the West Antarctic Ice Sheet that sits at the base of the South Pacific Ocean.
While previous studies suggested that winds coming off of the continental shelf - some 250 miles to the north - were pushing warm waters beneath the western Antarctic, warming the Pine Island Glacier and others from beneath, scientists from the University of East Anglia saw little evidence for that.
"People thought that it was the wind, at the edge of the continental shelf, that was determining how much water was pushed onto the shelf, warming the glacier from beneath," said Ben Webber, an oceanographer at the University of East Anglia and lead researcher on the study.
Instead, by analyzing a five-year set of records, Webber and his team found that local weather, rather than continental winds, were driving the ocean temperatures at a crucial depth between 1,150 to 2,300 feet, the range in which the base of the glacier comes into contact with ocean water.
"Most of the ocean data around Antarctica are snapshots of conditions - and many areas are only visited once every one or two years, if that," Povl Abrahamsen, co-author of the study and an oceanographer at British Antarctic Survey, said in a statement. "A five-year time series," he said, "lets us see what is happening between these snapshots, giving us insights into the processes driving the melting of Pine Island Glacier."