Evaluating Uncertainties in Reconstructing the Pre-eutrophic State of the North Sea

The North Sea is affected by eutrophication problems despite the decreasing riverine nutrient fluxes since late 1980s. Formally, assessment of state European marine environments based on their historical state. Model estimates are increasingly used to support monitoring data that often do not encompass such pre-eutrophic conditions. However, various sources uncertainties emerge when producing these estimates. In this study, we systematically quantify in terms variability, and assess importance for Sea. For reconstruction state, use two coupled physical-biogeochemical model systems: ECOHAM a 20-km grid shelf GPM high-resolution (1.5–4.5 km) Southern To gain insights into impacts due uncertainty loadings, consider inputs from alternative watershed-models (MONERIS E-HYPE). Overall, modeled historic E-HYPE shows higher concentrations compared MONERIS, especially coastal regions. Assessing degree methodological an inter-comparison different against natural variabilities provides insight reliability model-based We find regions influenced freshwater major rivers owed loading scenarios exceed variability. offshore regions, variability dominate over those caused model- scenario-related uncertainties. These findings expected assist decision makers researchers gaining confidence evaluating results, prioritizing need refinement models production reliable projections.