The ability to predict regional sea level changes over the next few decades takes on greater urgency as global carbon emissions continue to rise. The situation is especially dire in the Netherlands, which has large land masses below sea level. Understanding how regional sea level in the eastern North Atlantic will be affected by changes in ocean circulation is the primary goal of the eSALSA project.

eSALSA researchers are investigating regional effects caused by changes in the Atlantic Meridional Overturning Circulation (AMOC) through the use of an eddy-resolving ocean model, called the Parallel Ocean Model (POP). The project relies on four of the world’s most powerful supercomputers to visualize sea level changes with an unprecedented level of detail: 2 x 2 km resolution.

The project team includes Prof. Henk Dijkstra, eScience Integrator Climate Research & Project Leader, Dr. Jason Maassen, eScience Engineer, plus a cross-disciplinary team of oceanographers and engineers. In a recent video describing the project, the narrator explains that the melting Greenland ice shield, as a major contributor to rising sea levels, could prove disastrous for the Netherlands.

“It’s extremely important that we understand the consequences of this melt water on coastal sea levels,” says Prof. Henk Dijkstra, one of the physical oceanographers studying the phenomenon. “It’s a big dream of mine to simulate the ocean circulation and study how this effects sea level on coasts around the world.”

“One of the challenges researchers often face in realizing their high ambitions is the technical barrier – we always want to do research beyond the barriers of current technology,” he adds.

Researchers use the highest possible resolution they can, but they recognize that even if they had the dedicated resources of the biggest supercomputer in the world, it would still take months to run the large simulations.

eSALSA began in early 2013 and includes five collaborating organizations, the Netherlands eScience Center (NLeSC), the Institute for Marine and Atmospheric Research (IMAU) at Utrecht University, SURFnet, SURFsara and COMMIT. The project runs a 10Gbit/s connection linking four of the world’s fastest supercomputers: the Netherlands-based Cartesius, Emerald in the UK, Supermuc in Germany and Stampede in the United States.

The collaboration uses ultra-fast, long-distance networks called light paths and accelerator technologies, like GPU computing, to enhance computing power. The project is further aided by the cooperation of climate scientists, e-science engineers and infrastructure specialists. The results have been impressive, leading to details that were impossible to see before. For the first time, scientists can visualize the effects of ocean eddies on sea level thanks in large part to highly refined modeling. Originally at 100×100 kilometers resolution, two years later, the model was down to 10×10 kilometers. Now because of the eSALSA collaboration, the team has refined the resolution even further: to a ground-breaking 2×2 kilometers.

“Never before have global climate models achieved this extremely high resolution. It enables the team to make detailed simulations of the impact of Greenland’s melting ice sheet on rising sea level,” states the narrator.

“That’s why we’re here,” adds Dr. Maassen, “to allow the scientist to focus on the research questions without considering the technology to be a barrier.”

The team has taken a major step toward determining the significance of future sea level fluctuations on vulnerable coastal areas around the world, including the Netherlands, where the work is already having a direct impact on urban planning. For example, by knowing how high to build dykes along the coast, officials can take precautions to prevent disaster and save lives.