Gretta Pecl (University of Tasmania, Australia)
Martin Visbeck (IFM-GEOMAR, Germany)
Mike Litzow (University of Tasmania, Australia)
Jacob Schewe (Potsdam Institute for Climate Impact Research, Germany)
The ocean plays a central role in the regional and global climate system. Its circulation, temperature and salinity patterns, nutrient distributions and chemical composition are mainly influenced by changes in the atmosphere and fluxes from the land. This ocean state provides the basis for the marine ecosystem, which itself has several complex interdependencies. From complex system theory we know that many systems tend to respond in an almost linear fashion to changes in the forcing. However, at some point a critical value can be reached, and the system responds with a dramatic switch-like behavior into a new stable state, having passed a critical tipping point. Evidence for tipping points in nature is often generated only after the consequences of a major shift become obvious. Predicting the existence and effects of tipping points on ocean state or ecosystem function are major, and likely increasing, challenges for both scientists and resource managers. This session will provide an overview of some of the known tipping points in the marine system and invites contributions to elaborate on our mechanistic understanding of these or provide evidence or a strong theoretical basis for new tipping points. Disciplines to be covered range from ocean circulation dynamics, sea ice formation, de-oxygenation, through to dramatic shifts in ecosystem structure and function, and beyond.