Coastal polynias are open water areas which form when strong katabatic winds push the sea ice away from the coast (offshore). They have a strong influence on the heat and energy exchange between ocean and atmosphere since they are a gap in the insulating ice cover. In the polynias, water is cooled down and new ice is formed. The newly formed ice grows and is sometimes deformed.

Due to the geographic location of polynias, field experiments to study polynia processes are difficult and cost intensive. Additionally and field experiment is limited in time and area of the sampling and can only provide a snapshot of the polynia formation. Therefore satellite observations can provide a very useful tool for the analysis of polynia evolution. Within our project, we study the potential of the upcoming Sentinel satellites for polynia research. To do so, we employ older satellite images that have similar characteristics compared to the new generation of images. This combination of different satellites will help us to gain more information on polynia formation and the processes interacting there.

• Sea ice motion and open water area at the Ronne Polynia, Antarctica: Synthetic aperture radar observations versus model results

Thomas Hollands

The project "Kombination und Analyse von Daten verschiedener Satellitensensoren als Beitrag zur Erforschung von Polynjen in der Arktis und Antarktis" (Combination and analysis of data from different satellite sensors as a contribution to polynia research in the Arctic and Antarctic) is funded by the Federal Ministry for Economic Affairs and Energy.