Our research on the ocean’s role in the climate system is primarily done using regional climate models for 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).
The ocean and climate change
One of the main problems addressed by the group is to quantifty and understand the impacts of anthropogenic climate change. For instance, how will the Baltic Sea be affected by a warmer climate or a change in freshwater supply from rivers and precipitation.
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 “How sensitive is the ocean-ice-atmosphere interaction to climate change?”
Natural climate variability
Another topic on the group’s agenda is natural climate variability on time scales from years to decades. For instance, the group investigates drivers of long-term salinity fluctuations and variations in the areal extent of anoxic sediments in the Baltic Sea. Moreover, using models researcher are also able to predict how such things may change in the future given assumptions about how different drivers like nutrient loads, greenhouse gases and aerosols will change.
Tools of the trade
Climate models allows for process, sensitivity studies and scenario simulations where different possible futures can be investigated. Experiments of this type cannot be done 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.