title: Monitoring and modelling of biosphere/atmosphere exchange of gases and aerosols in Europe.
abstract: Monitoring and modelling of deposition of air pollutants is essential to develop and evaluate policies to abate the effects related to air pollution and to determine the losses of pollutants from the atmosphere. Techniques for monitoring wet deposition fluxes are widely applied. A recent intercomparison experiment, however, showed that the uncertainty in wet deposition is relatively high, up to 40%, apart from the fact that most samplers are biased because of a dry deposition contribution. Wet deposition amounts to about 80% of the total deposition in Europe with a range of 10-90% and uncertainty should therefore be decreased. During recent years the monitoring of dry deposition has become possible. Three sites have been operational for 5 years. The data are useful for model development, but also for model evaluation and monitoring of progress in policy. Data show a decline in SO(2) dry deposition, whereas nitrogen deposition remained constant. Furthermore, surface affinities for pollutants changed leading to changes in deposition. Deposition models have been further developed and tested with dry deposition measurements and total deposition measurements on forests as derived from throughfall data. The comparison is reasonable given the measurement uncertainties. Progress in ozone surface exchange modelling and monitoring shows that stomatal uptake can be quantified with reasonable accuracy, but external surface uptake yields highest uncertainty.
authors.affiliation: Energy Research Centre of the Netherlands (ECN), P.O. Box 1, 1755 ZG Petten, The Netherlands. erisman@ecn.nl
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Erisman
authors.forename: Alex
authors.initials: A
authors.lastname: Vermeulen
authors.forename: Arjan
authors.initials: A
authors.lastname: Hensen
authors.forename: Chris
authors.initials: C
authors.lastname: Flechard
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dämmgen
authors.forename: David
authors.initials: D
authors.lastname: Fowler
authors.forename: Mark
authors.initials: M
authors.lastname: Sutton
authors.forename: Ludger
authors.initials: L
authors.lastname: Grünhage
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Tuovinen
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants; D001272:Atmosphere / Q000737:chemistry*; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods; D005060:Europe; D005740:Gases / Q000032:analysis*; D008956:Models, Chemical; D017672:Nitrogen Compounds / Q000032:analysis; D010126:Ozone / Q000032:analysis; D013457:Sulfur Compounds / Q000032:analysis
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D005740:Gases; D017672:Nitrogen Compounds; D013457:Sulfur Compounds; D010126:Ozone