Venue

Scottish Executive
Victoria Quay
Edinburgh, UK
4-6 December 2006

Organisation

The workshop is organized and sponsored by CEH, Defra, SEERAD, COST729 and the NitroEurope IP

Draft Agenda

Workshop Objectives 

1. To assess the extent to which the existing critical thresholds for ammonia reflect current scientific understanding:

1. Examine the case for setting new ammonia critical threshold(s) based on current evidence of direct impacts of ammonia on different receptors;

2. Discuss the extent to which vegetation and sensitive ecosystems appear to be differentially sensitive to ammonia versus other forms of reactive N;

3. Debate the case for establishing indicative air concentration limits for indirect effects of ammonia, which would be consistent with current critical loads for nitrogen.

2. To assess the extent to which independent atmospheric measurements can verify where regional changes in NH3 emissions have and have not occurred:

   1. Quantify the extent to which estimated regional changes in ammonia emissions have been reflected in measurements of ammonia and ammonium in the atmosphere;

   2. Distinguish cases where the estimated changes in ammonia emission are due to altered sectoral activity or the implementation of abatement policies and thereby assess the extent to which atmospheric measurements verify the effectiveness of ammonia abatement policies;

   3. Make recommendations for future air monitoring and systems for assessing the national implementation of ammonia abatement policies and consider the implications of any non-linearities for integrated assessment models.

3. To review approaches for downscaling transboundary assessments to deal with ammonia hotspots in relation to operational modelling and monitoring:
   
   

1. Review current emission and atmospheric dispersion modelling methods for downscaling NH3 dispersion and deposition in hot spots;

2. Examine the status of methods for effect assessment and air monitoring in NH3 hot spots;

3. Recommend broad principles for assessment approaches in ammonia hot spots, including spatial approaches and the interactions between transboundary ammonia emission reduction targets and other policy measures.

4. To review mesoscale atmospheric transport and chemistry models in relation to their formulation and results for ammonia: 

1. Review emission parameterizations used in the models, establishing comparability, spatial and temporal resolution and uncertainties;

2. Review dispersion, air chemistry and deposition formulations identifying key differences and uncertainties;

3. Assess the overall performance of the models against measurements and against a common reference, leading to recommendations for improving mesoscale models of ammonia transport and deposition; including the implications of any non-linearities for source-receptor matrices and integrated assessment models.