They modeled sea level rise that first took into account ocean eddies: a kind of vortex tens of kilometers in diameter that keeps the sea warming at a distance from Antarctica.
Utrecht researchers – doctoral candidate Rene van Westen and Professor Henk Dikstra – published their insights Friday in the flagship journal Science Advances.
Their model differs from previous models in an important way. It works with much higher accuracy. In other words: in this model, the ocean is not divided into sections of 100 x 100 km, but 10 x 10 km. As a result, the ocean swirling effect can suddenly be included. This delicate entanglement already costs enormous computing power: the Dutch supercomputer has more than a year of computing time on it.
“What we see is that the warm waters are being kept away from Antarctica because of those ocean currents,” Van Westen says. In doing so, the ice in Antarctica becomes more isolated from the rest of the ocean. As a result, some regions near Antarctica are regressing even rather than warming – despite the warming of the ocean as a whole. ”
Decreased sea level rise
If the waters around Antarctica remained colder, ice shelves in the sea would melt less quickly. As a result, land ice slides less into the sea and sea level rise remains limited. According to the model of Dijkstra and Van Westen, the melting of the ice sheet will adhere to one-third of previous forecasts.
In the year 2100, it would make a difference about a quarter of the total sea level rise, after all, melting ice around Antarctica wasn’t the only cause of sea level rise. The disappearance of glaciers, the shrinking of the Arctic and the expansion of sea water also play a role.
“We were very surprised by the results,” says Van Westen. “You often read that the melting of Antarctica is accelerating, and expectations are deteriorating. Our article contains a more positive message.”
However, this new model is also not perfect. “Right now, the ice in West Antarctica in particular is melting fast,” Lambert says. “But you don’t see that in the model. To be able to make good predictions, you might have to work closely in the region near Antarctica.”