OMEX II

The aim of the OMEX II project it was to gain a better understanding of the physical, chemical, and biological processes occurring at the ocean margins in order to evaluate fluxes of energy and matter across this boundary. The objective was to provide a more accurate picture of the biogeochemical interactions between the coastal zone and the open ocean. This information is essential for the development of predictive models required to evaluate the response of the shelf and slope area to global environmental changes. The physical studies were mainly focused on the determination of advective and diffusive transport processes at the European shelf edge boundary using field measurements, laboratory experiments and theoretical analyses. Prognostic models were developed to estimate fluxes of water and particles in characteristic but contrasting systems of the Northeastern European shelf edge. Special efforts were devoted to the understanding of the various components of the carbon cycle and associated elements (nutrients, oligo-elements). This included the study of the temporal and spacial variability of production, consumption, transport and burial of organic matter. Ecological models were developed in order to assess the population dynamics in relation to the food flux with special emphasis on the pelagic-benthic coupling. The distribution, properties, transport and rate of accumulation of sediments in the selected areas were determined with particular consideration on the role of the nepheloid layer. The physical, chemical and biological aspects of the utilization or burial of organic and inorganic carbon in the sediments were studied by looking at the vertical distribution of dissolved and particulate matter. Finally the ocean margins often characterized by upwelling and enhanced biological activity, are essential areas to evaluate fluxes of gaseous components between the ocean and atmosphere. Determination of rates of exchange of CO2, CH4 and sulfur biogases were performed.