Ocean climate research

Ocean climate research is conducted mainly with regional climate models for the Baltic Sea, the North Sea and the Arctic. Investigations are to a large degree performed with the coupled atmosphere-ice-ocean model RCA4-NEMO-Nordic or single components of the system.

The regions in the present focus of the group are the Baltic Sea, the North Sea and the Arctic. The group deals with interactions between the atmosphere, the ice and the ocean on time scales from months till centuries (or even millennia). One of the main problems addressed by the group is the impact of anthropogenic climate change until 2100. For instance, how will the Baltic Sea be affected by a warmer climate or a change in freshwater supply? Changes in sea ice concentration or ventilation of the Baltic Sea do feed back onto the human society around the Baltic Sea directly through socio-economical adaptation or indirectly through eco-system changes. Other questions the group is dealing with are “How does a retreat of Arctic sea-ice affect the climate?” and “Is the ocean-ice-atmosphere interaction sensitive to climate change?”

Another topic on the group’s agenda is natural climate variability on time scales from years to decades. For instance, the group investigates drivers for long-term salinity fluctuations in the Baltic Sea. In general, regional coupled climate models such as RCA4-NEMO or RCAO driven by reanalysis products or global climate models are the main tools for investigations. The usage of climate models allows for process and sensitivity studies that are not possible using observations only. However, together with observations as a reference, the climate models are used to study climate dynamics sensitivity to external (anthropogenic) drivers and regional amplification of global climate change. Here, special focus is on the interaction between the atmosphere and the ocean in terms of heat and freshwater fluxes as well as gas exchange. The group investigates also how model results of individual model components benefit from the active coupling of those components.

Model domains of RCA4 and NEMO-Nordic
The topography of the regional atmosphere model RCA4 and the regional ocean model NEMO-Nordic. Illustration Matthias Gröger Enlarge Image