THE PUMA PROJECT AND SUBSEQUENT AIR QUALITY MODELLING AT THE UNIVERSITY OF BIRMINGHAM

1. THE PUMA PROJECT AND SUBSEQUENT AIR QUALITY MODELLING AT THE UNIVERSITY OF BIRMINGHAM ROY M. HARRISON AND XIAOMING CAI SCHOOL OF GEOGRAPHY, EARTH AND ENVIRONMENTAL SCIENCES THE UNIVERSITY OF BIRMINGHAM

2. MODELLING URBAN AIR POLLUTION • In the PUMA project funded through the NERC URGENT programme two numerical models of atmospheric chemistry across the West Midlands were developed: • - RAMS/UAM Eulerian model by University of Birmingham • - UM/NAME Lagrangian model by the Meteorological Office • (Professor Derwent, Drs Ryall, Redington and Manning) • RAMS describes meteorological fields within the conurbation on a 2x2 km grid • UAM, using the CBM IV chemical mechanism simulates atmospheric chemistry of NOx, VOC and ozone • Major adjustments to UAM were needed to accommodate the very different balance between advection and local formation of pollutants compared to the U.S. west coast

3. NERC URGENT PROGRAMME • POLLUTION OF THE URBAN MIDLANDS • ATMOSPHERE (PUMA) • CONSORTIUM: • UNIV. OF BIRMINGHAM HARRISON, CAI, McGREGOR • UNIV. OF CAMBRIDGE JONES • UNIV. OF LEEDS PILLING, SEAKINS, HEARD • UNIV. OF EAST ANGLIA PENKETT • MET. OFFICE RYALL, MALCOLM, DERWENT • CLOSELY ASSOCIATED • UNIV. OF LEICESTER MONKS, GALLAGHER • UMIST

4. DESIGN OF PUMA CAMPAIGNS UMIST AIRCRAFT Particle Measurements; NO2 CENTRAL SITE (EDGBASTON) Gases: CO, SO2, NO, NO2, O3, HCHO, PAN, HONO, HNO3 Particles: number, mass, size distribution; major component composition Free radical intermediates: OH, HO2, NO3 Meteorological and photochemical variables: w/s, w/d, turbulence, photolysis frequencies HALFPENNY GREEN (25 km WEST) Gases: NO, NO2, CO, O3 Particles: mass WITHYBROOK (35 km EAST) Gases: NO, NO2, CO, SO2, O3

5. RAMS Configuration r Two nested grids are configured r Surface land dataV Terrain: Met Office (1km) and US SGS (30”)V Landuse type: Institute of Territorial Ecology (1km)V Roughness: Met Office (1km) and ITE-derivedr Meteorological initial and boundary conditionsV UK Met Office’s Unified model output

6. Fig.1 Configuration of the nested grids. The figure box is the boundary of Grid 1 and the embedded box is the boundary of Grid 2. Solid squares are synoptic scale surface stations.

7. Fig.2 Modelling domain for Grid 2. Solid squares are synoptic scale surface stations and solid triangles are PUMA sites.

10. URBAN AIRSHED MODEL: UAM IV • Driven by RAMS meteorology • Contains CBM IV chemical scheme • Eulerian grid model formulation. 1 x 1 km emissions from NAEI • Reasonable predictions of CO and NOx with slight tendency to under-predict • Produces insufficient ozone in simplest form of model • Modified to: • Allow for downward mixing of ozone-rich air as the morning boundary layer expansion occurs • Assimilate hourly boundary condition information for ozone

11. COMPARISON OF O3 FOR 10 JUNE – 10 JULY 1999

12. NOX DURING WINTER CAMPAIGN

13. Surface concentration of NO, NO2 and O3 on 24/6/1999 NO NO2 O3

14. NO2 and O3 on 11-12 June 1999

15. Experimental quantification and modelling of dispersion of particles in urban street canyons (URGENT) • Obtain information on rates of emission of particles from road surfaces into the atmosphere (R Kinnersley and T Huggins) • Use the data obtained, together with other ongoing wind tunnel work, to predict particulate concentration at the end of vehicle near wakes (C Baker and T Huggins) • Develop a large eddy simulation model of street canyon geometries to predict the unsteady wind fields, particle concentrations within the canyon and fluxes from the canyon (C Baker, X Cai and Z Cui)