Research Group Ocean Physics
Many consequences of ongoing anthropogenic climate perturbations are irreversible with respect to human timescales, i.e. they will last for several hundred to thousand years. These longterm climate changes are not in the scope of common efforts of climate projections (e.g. IPCC). To understand the longterm behavior of the climate system requires to involve also those climate components with a large inertia (especially ice sheets, but also carbon cycle), which are generally not considered in standard anthropogenic climate change simulations.
The 'Ocean Physics' group aims at identifying and understanding the major climate processes and internal feedback loops relevant for the longterm climate evolution. In order not to neglect potential feedbacks the individual compartments are modelled by complex models rather than by highly simplified models. Nevertheless, the model resolution must be relative coarse in order to be able to perform the rather long integrations required for the investigations.
Special emphasis is laid on paleoclimate changes that have been preserved in natural climate archives. They may serve as a potential analog for future climate warming, and give the opportunity to investigate climate mechanisms associated with known and well documented past climate fluctuations (e.g. Heinrich events etc), and on the other hand and allow to test and validate the models used for predicting anthropogenic climate change in a different parameter range.
As many climate processes are scale invariant, results of global climate models can be used to predict regional climate changes. For this, dynamical downscaling methods are applied to investigate the impact of global climate changes for regions of high climate sensitivity (e.g. Arctic, North Atlantic etc.) and for regions of particular interest like the North Sea, Mediterranean etc.