Standard images are available on the intranet For more specific images please contact Matthew Hart For PowerPoint help please contact Elizabeth Leishman The response of secondary inorganic particulate matter to precursor emission reductions in south-east England June 2006 Andrea Fraser 1,2, Prof. Helen M ApSimon 1, Prof. Richard G. Derwent 3, 1 Imperial College London 2 AEA, Harwell, Oxfordshire, UK 3 rdscientific Outline Summary of the CMAQ simulation in south-east England 3 rd June 9 th July Evaluation of the inorganic PM components with observations at Harwell monitoring site. Spatial interaction of inorganic PM components. Effects of SO 2 NO X or NH 3 emission reductions. CMAQ simulation south-east England Meteorology Data from the UK Met. Office operational Unified Model (MetUM) are archived at the British Atmospheric Data Centre. Data are processed with a UM-MCIP program to create CMAQ ready files. Emissions European emissions are prepared from the x50km annual EMEP emissions UK emissions are prepared from the x1km annual NAEI emissions European Natural emissions calculated using a Biogenic Potential Inventory CMAQ V CB IV Chemistry A1 Europe 48 x 48 km resolution 24 layers 8 below 600m MetUM Global Meteorology 3hr time steps 40x40km (approx) 38 layers Emissions EMEP 2003 A2 Northern Europe 12 x 12 km resolution 24 layers 8 below 600m MetUM UK Meteorology 1hr time steps 12x12km (approx) 38 layers Emissions EMEP 2003 NAEI 2003 A3 South-East England 4 x 4 km resolution 24 layers 8 below 600m MetUM UK Meteorology 1hr time steps 12x12km (approx) 38 layers Emissions EMEP 2003 NAEI 2003 A3 South-East England Rural site Harwell Didcot Power station Heathrow Airport Southampton and Refineries on the Solent Power stations in the Thames estuary inc. Tilbury Dover and cross channel shipping lanes Central London M25 Model Evaluation Harwell 39% of model values within a factor of 2 of the observation 40% for 18 sites in SE England varying from 54% (Urban background) to 20% (roadside) Observed (TEOM) and Modelled PM 2.5 (g m -3 ) 3 rd June to 9 th July 2006 EMEP intensive monitoring program Harwell is one of the EMEP measurement site. During June 2006 there was an intensive European monitoring program when additional PM component measurements were made. SO 4 2- SO 2 NO 3 HNO 3 NH 4 + NH 3 EMEP - Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe. Data were made available by Eiko Nemitz, CEH Edinburgh Evaluation of SO 2 and SO 4 2- with observations at Harwell SO 4 2- SO 2 + SO 4 2- SO 2 49% within a factor of 2 Evaluation of HNO 3 and NO 3 - with observations at Harwell NO 3 - HNO 3 + NO 3 - HNO 3 18% within a factor of 2 65% within a factor of 2 Evaluation of NH 3 and NH 4 + with observations at Harwell NH 4 + NH 3 + NH 4 + NH 3 54% within a factor of 2 48% within a factor of 2 Spatial interaction of inorganic PM components Emission reduction scenarios 30% across-the board reduction in SO 2 30% across-the board reduction in NO x 30% across-the board reduction in NH 3 Emission sensitivity coefficient = % change in PM component % change in Emission 1 A 30% reduction in emission gives a 30% reduction in PM component >1 A 30% reduction in emission gives more than a 30% reduction