title: Establishing the link between ammonia emission control and measurements of reduced nitrogen concentrations and deposition.
abstract: In the context of international efforts to reduce the impacts of atmospheric NH3 and NH4+ (collectively, NHx). it is important to establish the link between NH3 emissions and monitoring of NHx concentrations and deposition. This is equally relevant to situations where NH3 emissions changes are certain (e.g. due to changed source sector activity), as to cases where NH3 abatement technologies have been implemented. Correct interpretation of adequate atmospheric measurements is essential, since monitoring data provide the only means to evaluate trends in regional NH3 emissions. These issues have been reviewed using available measurements and modelling from nine countries. In addition to historic datasets, the analysis here considers countries where NH3 source sector activity changed (both increases and decreases) and countries where NH3 abatement policies have been implemented. In The Netherlands an 'ammonia gap' was identified between the expected reduction and results of monitoring, and was attributed initially to ineffectiveness of the abatement measures. The analysis here for a range of countries shows that atmospheric interactions complicate the expected changes, particularly since SO2 emissions have decreased at the same time, while at many sites the few years of available data show substantial inter-annual variation. It is concluded that networks need to be established that speciate between NH3 and aerosol NH4+, in addition to providing wet deposition, and sample at sufficient sites for robust regional estimates to be established. Such measurements will be essential to monitor compliance of the international agreements on NH3 emission abatement.
authors.affiliation: Centre for Ecology and Hydrology (CEH), Edinburgh Research Station, Bush Estate, Penicuik, Scotland, UK. ms@ceh.ac.uk
authors.forename: Mark A
authors.initials: MA
authors.lastname: Sutton
authors.forename: Willem A H
authors.initials: WA
authors.lastname: Asman
authors.forename: Thomas
authors.initials: T
authors.lastname: Ellermann
authors.forename: J A
authors.initials: JA
authors.lastname: Van Jaarsveld
authors.forename: Karin
authors.initials: K
authors.lastname: Acker
authors.forename: Viney
authors.initials: V
authors.lastname: Aneja
authors.forename: Jan
authors.initials: J
authors.lastname: Duyzer
authors.forename: Laszlo
authors.initials: L
authors.lastname: Horvath
authors.forename: Sergey
authors.initials: S
authors.lastname: Paramonov
authors.forename: Marta
authors.initials: M
authors.lastname: Mitosinkova
authors.forename: Y Sim
authors.initials: YS
authors.lastname: Tang
authors.forename: Beat
authors.initials: B
authors.lastname: Achermann
authors.forename: Thomas
authors.initials: T
authors.lastname: Gauger
authors.forename: Jerzy
authors.initials: J
authors.lastname: Bartniki
authors.forename: Albrecht
authors.initials: A
authors.lastname: Neftel
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Erisman
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000331:legislation & jurisprudence / Q000517:prevention & control*; D000641:Ammonia / Q000032:analysis / Q000737:chemistry*; D004784:Environmental Monitoring / Q000592:standards; D019983:Guideline Adherence; D007391:International Cooperation; D009426:Netherlands; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D000641:Ammonia; D009584:Nitrogen