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

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 NO x, 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

NERC URGENT PROGRAMME POLLUTION OF THE URBAN MIDLANDS ATMOSPHERE (PUMA) CONSORTIUM: UNIV. OF BIRMINGHAMHARRISON, CAI, McGREGOR UNIV. OF CAMBRIDGEJONES UNIV. OF LEEDSPILLING, SEAKINS, HEARD UNIV. OF EAST ANGLIAPENKETT MET. OFFICERYALL, MALCOLM, DERWENT CLOSELY ASSOCIATED UNIV. OF LEICESTERMONKS, GALLAGHER UMIST

DESIGN OF PUMA CAMPAIGNS UMIST AIRCRAFT Particle Measurements; NO 2 HALFPENNY GREEN (25 km WEST) Gases: NO, NO 2, CO, O 3 Particles: mass CENTRAL SITE (EDGBASTON) Gases: CO, SO 2, NO, NO 2, O 3, HCHO, PAN, HONO, HNO 3 Particles: number, mass, size distribution; major component composition Free radical intermediates: OH, HO 2, NO 3 Meteorological and photochemical variables: w/s, w/d, turbulence, photolysis frequencies WITHYBROOK (35 km EAST) Gases: NO, NO 2, CO, SO 2, O 3

RAMS Configuration r Two nested grids are configured rSurface land data VTerrain: Met Office (1km) and US SGS (30”) VLanduse type: Institute of Territorial Ecology (1km) VRoughness: Met Office (1km) and ITE-derived rMeteorological initial and boundary conditions VUK Met Office’s Unified model output

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.

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

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 NO x 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

COMPARISON OF O 3 FOR 10 JUNE – 10 JULY 1999

NO X DURING WINTER CAMPAIGN

Surface concentration of NO, NO 2 and O 3 on 24/6/1999 NONO 2 O3O3

NO 2 and O 3 on June 1999

 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) Experimental quantification and modelling of dispersion of particles in urban street canyons (URGENT)