A new marine ecosystem 3D CEMBS model (version 2) for the Baltic Sea

The paper presents a new marine ecosystem model designed for the Baltic Sea. The ecosystem 3D CEMBS model has been developed for incorporation into the 3D POPCICE ocean-ice model. The Current Baltic Sea model is based on the Community Earth System Model (CESM from NCAR - the National Center for Atmospheric Research). CESM was adapted for the Baltic Sea as a coupled sea-ice model. It consists of the Community Ice Code (CICE model, version 4.0) and the Parallel Ocean Program (version 2.1). The ecosystem model - the biological submodel consists of eleven mass conservation equations. There are eleven partial second-order differential equations of the diffusion type with the advective term for phytoplankton (three classes: small and large phytoplankton and cyanobacteria), zooplankton, nutrients (four components: NO3, NH4, PO4 and SiO3), dissolved oxygen, and dissolved and particulate organic matter (DOM and POM). This model is an effective tool for solving the problem of ecosystem bioproductivity and was tested for five selected localities.