Deposition monitoring networks: what monitoring is required to give reasonable estimates of ammonia/ammonium?
Deposition is one of the main loss terms for ammonia and ammonium from the atmosphere. It is also the input for ecosystems that can lead to drastic changes and effects. Deposition networks are needed to evaluate the need and the effect of policies to reduce nitrogen emissions, but also for studying deposition parameters and for developing deposition models. As with ambient concentrations of ammonia, deposition, especially dry deposition, varies strongly in space and in time. Furthermore, the bi-directional surface-atmosphere exchange of ammonia makes the combination of ambient concentration measurements with inferential models inadequate. Developing deposition monitoring networks with reasonable accuracy and representativeness is therefore not straightforward. In Europe several projects have addressed deposition monitoring. From these results it is concluded that a monitoring strategy should consist of a network with a limited amount of super sites combined with a larger number of sites where low cost methods are applied, together with models for generalisation.
Erisman
Jan Willem
JW
ECN, P.O. Box 1, 1755 ZG Petten, The Netherlands. erisman@ecn.nl
Hensen
Arjan
A
Mosquera
Julio
J
Sutton
Mark
M
Fowler
David
D
D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis*; D001272:Atmosphere / Q000032:analysis*; D003365:Costs and Cost Analysis; D017753:Ecosystem; D004784:Environmental Monitoring / Q000191:economics / Q000379:methods*; D005060:Europe; D008956:Models, Chemical; D000644:Quaternary Ammonium Compounds / Q000032:analysis*
D000393:Air Pollutants; D000644:Quaternary Ammonium Compounds; D000641:Ammonia