Dispersion, deposition and impacts of atmospheric ammonia: quantifying local budgets and spatial variability
Sutton, M. A.; Milford, C.; Dragosits, U.; Place, C. J.; Singles, R. J.; Smith, R. I.; Pitcairn, C. E. R.; Fowler, D.; Hill, J; Apsimon, H. M.; Ross, C.; Hill, R.; Jarvis, S. C.; Pain, B. F.; Phillips, V. C.; Harrison, R.; Moss, D.; Webb, J.; Espenhahn, S. E.; Lee, D. S.; Hornung, M.; Ullyett, J.; Bull, K. R.; Emmett, B. A.; Lowe, J.; Wyers, G. P.. 1998 Dispersion, deposition and impacts of atmospheric ammonia: quantifying local budgets and spatial variability. Environmental Pollution, 102 (S1). 349-361. 10.1016/S0269-7491(98)80054-7Full text not available from this repository.
Ammonia is a reactive pollutant emitted primarily by agricultural sources near ground level in the rural environment. The consequence of these factors is that, in addition to the effects of long-range pollutant transport, ammonia has major effects at a local scale, with emission and receptor areas often closely located in the rural landscape. There is a substantial local spatial variability that needs to be considered in effects assessments, while variations in local deposition may affect the amount of ammonia available for impacts further afield. The wide-ranging UK programme ADEPT (Ammonia Distribution and Effects ProjecT) has addressed these issues through a combination of measurement and modelling activities concerning the distribution of emissions, atmospheric transport, deposition and effects assessment. The results are illustrated here by summarizing the findings of a joint experiment at Burrington Moor, Devon, and wider modelling contrasting the variability at a field scale with 5 km resolution estimates for the UK. The fraction of emitted NH3 deposited locally is shown to depend critically on the downwind land-cover, with fluxes being dependent on interactions with the ammonia compensation point. This will restrict deposition back to agricultural land, but may mean that non-conservation woodlands could be of benefit to recapture a significant fraction of emissions. The generalized models demonstrate the high spatial variability of ammonia impacts, with a case study being used to show the consequences at a field scale. In source regions substantial variability occurs at sub-1 km levels and this will have major consequences for the emission reduction targets needed to protect ecosystems.
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry|
|CEH Sections:||_ Pre-2000 sections|
|Additional Keywords:||Ammonia, emission, inventory, modelling, compensation point, mapping, critical loads|
|NORA Subject Terms:||Atmospheric Sciences|
|Date made live:||04 Sep 2008 09:56|
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