Short summary

FESOM-C is a newly designed Coastal branch of the global Finite Element (VolumE) Sea-ice Ocean Model FESOM2. It is developed to focus on smaller scales than FESOM and on physical and dynamical processes commonly not accounted in the large-scale models. FESOM-C numerical core is created in a way to provide the most efficient coupling between coastal and global solutions. ​ FESOM is the first model worldwide that provides multi-resolution functionality to large-scale ocean modeling, allowing to bridge the gap between scales. This unique feature is crucial for high efficient coupling, as soon as the exchange zone can be resolved similarly (with the same resolution) by the global and local solutions. Additional strong side of the elaboration of the coastal branch for the existing global model is the possibility to organize flux treatment in the same manner, increasing efficiency of coupling.
The further development of the FESOM-C and FESOM-C+FESOM coupled solution was supported during the AWI evaluation process.

Main scientific problem

The coastal zones and Deep Ocean evolve in time as one entity. However, there is still a substantial gap in understanding of the deep signal fate in the coastal areas and the role and feedbacks of the shelf processes with the wider system.


Answer questions on the shelf observed and future trends and dynamic features across time and space scales.

How? What is new and challenging?

Tracing water masses, sea ice, biogeochemical and ecological signals from the Estuaries/coastal zone to the Arctic Ocean/Global Ocean through the shelf in both upscaling and downscaling directions.

Key applications

  • Formation, spreading and mixing of the water masses on the shelf and its transport to the deep ocean (and vice-versa); quantification of the influence of these processes on the thermohaline structure of the Global Ocean (and vice-versa); estimation of the particular roles of the driving factors in transport and mixing processes;
  • Impact of sea level rise on terrestrial zones;
  • Inter-annual  variability of the physical parameters in the coastal zones, where large scale signal plays significant non-trivial roles;
  • Mesoscale eddies, its transport on-shelf and importance for the shelf dynamics;
  • Coastal upwelling and its influence on the biogeochemical cycle of the shelf-deep ocean;
  • Tidal residual circulation on the shelf and its changes under the influence of the climatic factors;
  • Polynyas formation and functioning under the different conditions;
  • Gas hydrates state in the near shore area under the influence of the Arctic Ocean and river waters and modern climatic conditions;

Key features

  • Cell-vertex   finite  volume  discretization;
  • Share part of the infrastructure with FESOM;
  • Any configurations of triangular, quadrangular or hybrid meshes;
  • External/internal modes;
  • Terrain following vertical coordinate;
  • 3rd-order upwind horizontal advection schemes;
  • Implicit 3d-order vertical advection schemes, implicit vertical viscosity;
  • Biharmonic horizontal viscosity augmented to the Smagorinsky viscosity;
  • GOTM turbulence library for the vertical  mixing;
  • Rivers through solid boundary in streaming form/ Rivers as open boundary conditions;
  • Tidal potential /Open boundary prescription of amplitudes and phases for 12 harmonics;
  • Wetting/drying;
  • Simple sediment module

Key publication

Current applications

  • Hydrodynamics of the North Sea with focus on the deep ocean water mass signal fate
  • Temporal and special  dynamics of eukaryotic microbial communities in the German Bight
  • Non-linear aspects of the tidal dynamics in the Sylt-Rømø Bight, south-eastern North Sea
  • SPM dynamics in the Potter Cove