Movement, distribution, and thickness

How the sea ice moves is important for where ice forms and where it melts, and where the ice is thin and where it is thick. At the Nansen Center, we have developed a unique sea-ice model that can recreate the ice’s actual movements. The model is called “neXtSIM” and it has a unique way of simulating how the ice is pressed together and forms ridges, or cracks open and forms leads. In traditional sea-ice models, the ice movements have not been correctly calculated. “neXtSIM” is based on newer mathematical calculation methods that make it possible to simulate how the ice cracks open. The model can also be used to see what effect wind and ocean currents have on the ice.

We also research the extent and thickness of the sea ice. In winter, new ice forms, and this ice cover spreads south. When summer comes, some of the ice melts and the ice cover shrinks again. In recent decades, the distribution has changed, both in summer and winter. We see that the extent of sea ice has decreased, and the ice has become thinner. Climate change could lead to ice-free summers in the Arctic in a few decades. We examine the ongoing changes, what causes them, and how they relate to climatic conditions in other geographical areas. This is done using “neXtSIM” and with the help of satellite data. Our knowledge can be used to explain what is happening and to calculate the consequences of the changes.