The CLIMBER-3 project seeks to develop an Earth System model of intermediate complexity (EMIC). This model will be the next generation EMIC beyond the highly successful CLIMBER-2 model; it will incorporate a 3D ocean general circulation model, a better resolution atmosphere, and many other major improvements. The model will be efficient enough for performing many simulations on the multi-millennia time scale, and the greatly improved geographical resolution will allow many applications beyond the scope of CLIMBER-2. Applications include studies in paleoclimate, anthropogenic climate change and model uncertainty analysis.


Model Components

The Ocean Model - MOM3
The Atmospheric Model - POTSDAM 2

The Sea-Ice model - ISIS


Earth System Models of Intermediate Complexity (EMICs) attempt to overcome the gap between simple and comprehensive models (see review by Claussen et al. (2002)). Such models describe a considerable number of processes and feedbacks in the climate system, generally including more components than most coupled atmosphere-ocean general circulation models (AOGCMs).  Thanks to their low spatial resolution and simplified governing equations, they are computationally less expensive.

The CLIMBER-3 project seeks to develop an EMIC of a new generation, beyond the highly successfull CLIMBER-2. The CLIMBER-3α EMIC represents the first version of this next generation. It has evolved from CLIMBER-2. The main difference with respect to CLIMBER-2 is its oceanic component, which has been replaced by a state-of-the art ocean model including an ocean general circulation model (OGCM), a biogeochemistry module and a state-of-the-art sea-ice model. The atmospheric resolution was slightly increased. Thus, CLIMBER -3α includes modules describing the atmosphere, land-surface scheme, terrestrial vegetation, ocean, sea-ice, and ocean biogeochemistry.

Due to its relatively simple atmospheric component it is approximately two orders of magnitude faster than coupled AOGCMs, allowing the integration of a much larger number of integrations and sensitivity studies, as well as longer simulations. At the same time its oceanic component confers to it a larger degree of realism compared to those EMICs which include zonally averaged oceanic components. The model is thus suited for large-scale climate dynamics with a special focus on the ocean dynamics.

The coupling does not include flux corrections for heat and freshwater fluxes. Exchange of momentum fluxes between the ocean and the atmospehre is semi-interactive. The comparison against the climatologies shows that CLIMBER-3α describes satisfactorily the large-scale characteristics of the atmosphere, ocean and sea-ice on seasonal timescales (Gregory et al., 2005)

The CLIMBER-3α model is applied in the PIK-projects AO-Quest, C-Quest, ICE-Quest and  INTEGRATION.