Development of long-term reactive N flux network in Europe

Long term dry deposition of ammonia (NH3) and nitric acid (HNO3) can have a detrimental effect on sensitive ecosystems. Knowledge of the dry deposition of these two reactive N gases is through primarily short intensive field campaigns, as a result of the difficulty in measuring fluxes of both gases due to their sticky nature. Deposition models have been developed based on this knowledge, and they are used in conjunction with long-term concentration measurements to infer a flux over different ecosystems, but results are still uncertain (Flechard et al., 2010). As a result, information is limited on the variations across ecosystems and climatic conditions. The following work focuses on the development of a low cost, long-term flux monitoring approach for reactive nitrogen over different ecosystems to obtain more direct, measurement based ecosystem inputs. The COnditional Time Average Gradient (COTAG) system was developed to carry out long term average flux measurements of NH3 and HNO3, based on a well established system in the UK (Famulari et al. 2009). The COTAG was then deployed to 15 European sites as part of the NitroEurope IP