Research infrastructures as modular platforms for reactive nitrogen deposition monitoring

The need for large-scale monitoring of greenhouse gas emissions has led to the emergence of highly standardised, globally distributed research networks that measure the biosphereatmosphere exchange of CO2, N2O, and CH4 with micrometeorological methods. We argue that an effort towards monitoring reactive nitrogen (Nr) exchange should aim to build on these existing infrastructures. Recent developments allow for the implementation of a lowcost Nr deposition monitoring network based on inferential modelling in the short-term, and for equipping existing micrometeorological towers with fast-response analysers for continuous Nr flux measurements in the mid- to long-term.

Large-scale, representative, and nation-wide Nr deposition monitoring is desperately needed to evaluate the impacts of environmental protection efforts, and to identify ecosystems threatened by critical load exceedances. This need is not met across a wide range of different ecosystems due to significant challenges involved with measuring Nr deposition.