Advances in micrometeorological methods for the measurement and interpretation of gas and particle nitrogen fluxes

The application of micrometeorology for flux measurements of nitrogen speci es between terrestrial ecosystems and the atmosphere and some of their main limitations are reviewed. New methods which are gaining rapid acceptance s uch as relaxed eddy accumulation are also described. A new development to p rovide long term average fluxes by time averaged gradients is shown to yiel d long-term average NH3 fluxes over moorland within 10% of values obtained using continuous wet denuder methods and at less than 10% of the cost. The use of mass balance methods to quantify fluxes at the plot, landscape and r egional scale are described, and show that in suitable conditions and for s ome countries, methods to check national inventories of radiatively active gases are now available.