Observations show that the ice sheets in Greenland and the Antarctic are changing rapidly. The glaciers at the edges of the ice sheets are now flowing more rapidly: this means that they transport more ice from the land’s interior to the ocean, which in turn causes the sea level to rise. Furthermore, the surface of Greenland’s ice sheet is melting more extensively and is therefore losing mass. Modelling the many complex processes and understanding their interactions is an enormous challenge for us scientists. At the AWI, we use what are known as ‘continuum mechanics methods’, which allow us to simulate the behaviour of the ice sheets. Many of these simulations predict the future development of the ice sheets. We also model and investigate processes such as iceberg calving, the compression of snow to firn and then to ice, as well as subglacial hydrology. The latter includes research questions like: how much liquid water is there beneath the ice sheet? How does it get there, and to what extent does it influence the flow rate of the ice masses?
We also develop methods for analysing satellite data, in order to quantify the ice sheets’ contribution to global sea-level rise, and to detect and observe changes in the glacier systems. Satellite data is also needed for process studies and data simulations. To investigate all these aspects, we work with high-resolution radar satellites, optical satellites and satellite-based altimeters (which measure surface elevation).
To date, our studies have above all shown us one thing: in reality, the ice masses in Greenland and the Antarctic are changing more rapidly and dramatically than our models suggest – a cold, wet, multi-scale problem that isn’t easy to solve.