DFF - Danish coastal waters as hotbeds of nitrous oxide emission – a mechanistic assessment

N2O is a powerful greenhouse gas and ozone destroyer, and marine systems are an important source of atmospheric N2O, with oxygen-depleted waters exhibiting particularly high concentrations and emissions. Eutrophic conditions and seasonal oxygen depletion implicate Danish coastal waters as hotbeds of N2O emission, but neither the dynamics nor the emissions of N2O have been asessed. We propose an experimental investigation of nitrous oxide (N2O) dynamics in Danish coastal marine systems subject to oxygen depletion. We will analyse spatial and temporal distributions of N2O, elucidate pathways, rates, environmental controls, and kinetics of N2O production and consumption, and identify the key microbes involved in N2O cycling and analyse their metabolism. The project will deliver the first estimate of Danish marine N2O emissions as well as a quantitative predictive framework to estimate the response of emissions to environmental change and guide marine environmental management.