The session would like to overview recent understanding, by observations and modelling, of the Southern European Seas general circulation, their ecosystems and biogeochemical fluxes. Themes of particular interest are hydrodynamic interactions at multiple temporal and spatial scales, response to atmospheric forcing and process coupling at different trophic levels of the ecosystem. Issues related to long and short term circulation, mesoscale variability, biogeochemical flux dynamics, ocean forecasting, assessment and understanding of climate trends and the state of the ecosystem are also within focus of the session.