A new estimate says that Antarctic winds may have a profound impact on warming ocean temperatures under the ice shelves along the coastline of West and East Antarctic. They have also been shown to have implicated southern Australia’s drying climate.
Because of this, projected changes in the winds circling the Antarctic may accelerate global sea level rise significantly more than previously believed. Most sea level studies focused their attention towards the rate of ice shelf melting due to global warming of the ocean over vast areas.
Using super computers at Australia?s National Computational Infrastructure (NCI) Facility, the researchers were able to look into the impact of changing winds on currents down to 700m around the coastline in greater detail than ever before. The authors believe previous global models did not adequately capture these currents at the structure of water temperatures at these depths according to Science20.
“When we included projected Antarctic wind shifts in a detailed global ocean model, we found water up to 4?C warmer than current temperatures rose up to meet the base of the Antarctic ice shelves,” said lead author Dr. Paul Spence from the ARC Centre of Excellence for Climate System Science (ARCCSS). “The sub-surface warming revealed in this research is on average twice as large as previously estimated with almost all of coastal Antarctica affected. This relatively warm water provides a huge reservoir of melt potential right near the grounding lines of ice shelves around Antarctica. It could lead to a massive increase in the rate of ice sheet melt, with direct consequences for global sea level rise.”
Unexpectedly, this more detailed approach suggests change sin Antarctic winds due to climate change and their impact on coastal currents could raise more of a concern on the melting of ice shelves than the broader warming of the ocean.
“When we first saw the results it was quite a shock. It was one of the few cases where I hoped the science was wrong,” Spence said. “But the processes at play are quite simple, and well-resolved by the ocean model, so this has important implications for climate and sea-level projections. What is particularly concerning is how easy it is for climate change to increase the water temperatures beside Antarctic ice sheets.”
The researchers believe their new estimate may help to explain a number of sudden and unexplained increases in global sea levels that occurred in the geological past. Recent estimates show the West Antarctic Ice Sheet alone could contribute 3.3 meters to long-term global sea level rise.
Estimate: Antarctic Winds Impact Warming Ocean Temperatures