Nitrogen deposition in the UK: The influence of grid-space and time on the exceedance of critical loads and levels

Atmospheric transport models may be applied to run historic emissions scenarios, which are important in order to assess the correlation between monitored change in ecosystem health and biodiversity and changes in nitrogen inputs. The ability of models to calculate the response of nitrogen deposition to future emissions scenarios is of importance for policy makers to assess the benefits of implementing controls on atmospheric nitrogen emissions. Here we apply a relatively simple Lagrangian model, the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME) model to estimate the spatial distribution of nitrogen deposition in the UK, past and estimated future changes and the exceedance of critical loads. A second important issue concerns the grid resolution of the model simulation. We consider the difference in environmental impact criteria obtained with model simulations at 5 km and 1 km