Ecosystem modelling in the Gulf of Finland. II. The aquatic ecosystem model FINEST

A coupled circulation and water ecosystem model is presented. The description of the hydrodynamic model is given in the previous paper (Tamsalu & Myrberg, Estuarine Coastal and Shelf Science 41, 249–273). The calculations in the FINEST model are carried out in two phases. In the first step the two-layer, two-dimensional hydrodynamic parameters (current velocity, temperature, salinity, density, sea-level fluctuation and turbulent fluxes) are calculated. After that the results of the hydrodynamic model are used as the input data for the aquatic ecosystem characteristics calculation. In the FINEST model the conception of a size-structured plankton food-web is used. The biochemical reactions in the plankton community (growth rate, metabolism, etc.) are described depending on organism size. The FINEST model was used for simulations of seasonal and long-term variations in the Gulf of Finland ecosystem. For seasonal calculations the finite-difference method was applied and for long-term calculations the box method was applied.