Towards Coupling Three Dimensional Eddy Resolving General Circulation and Biochemical Models in the Black Sea

Abstract

An overview of our ongoing efforts on modeling the Black Sea general circulation and lower trophic level pelagic food web is presented. Using an eddy resolving ocean circulation model endowed with active thermodynamics and turbulence closure parameterization, a synthesis of the yearly mean and monthly varying circulations driven by the climatological wind stress, air-sea thermohaline fluxes and lateral buoyancy fluxes is given first. The main features of the vertically resolved, three dimensional biochemical model involving interactions between the inorganic nitrogen (nitrate, ammonium), phytoplankton, herbivorous Zooplankton and bacterial biomasses, detritus and dissolved organic nitrogen are then described. A simplified version (depth and time) of the coupled physical-biochemical model without having the horizontal variabilities is applied to the central Black Sea conditions. Given a knowledge of physical forcing, solar radiation and subsurface nutrient source, the coupled model simulates main observed seasonal and vertical characteristic features such as formation of the Cold Intermediate Water mass, yearly evolution of the upper layer stratification, the annual cycle of phytoplankton production with the fall and spring blooms, the subsurface maximum layer in summer, as well as realistic patterns of bacterial biomass and particulate and dissolved organic materials.