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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 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
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 ASSOCIATEDUNIV. OF LEICESTER MONKS, GALLAGHERUMIST
DESIGN OF PUMA CAMPAIGNS
UMIST AIRCRAFTParticle Measurements; NO2
HALFPENNY GREEN(25 km WEST)Gases: NO, NO2, CO, O3
Particles: mass
CENTRAL SITE(EDGBASTON)Gases: CO, SO2, NO, NO2, O3, HCHO, PAN, HONO, HNO3
Particles: number, mass, size distribution; major component compositionFree radical intermediates: OH, HO2, NO3
Meteorological and photochemical variables: w/s, w/d, turbulence, photolysis frequencies
WITHYBROOK(35 km EAST)Gases: NO, NO2, CO, SO2, O3
RAMS Configuration Two nested grids are configured
Surface land dataTerrain: Met Office (1km) and US SGS (30”)Landuse type: Institute of Territorial Ecology (1km)Roughness: Met Office (1km) and ITE-derived
Meteorological initial and boundary conditionsUK Met Office’s Unified model output
Grid Lx(km)
Ly(km)
Lz(km)
Nx Ny Nz x (km) y (km)
1 480 248 18 60 48 31 8.0 8.0
2 132 100 18 66 50 31 2.0 2.0
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 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
COMPARISON OF O3 FOR 10 JUNE – 10 JULY 1999
Comparison of O3 for 10 June - 10 July 1999
0
10
20
30
40
50
60
70
80
90
100
10-Jun 15-Jun 20-Jun 25-Jun 30-Jun 5-Jul 10-Jul
Time
O3
(pp
b)
O3 UAM
O3 Obs
k
NOX DURING WINTER CAMPAIGN
Birmingham East
0
50
100
150
200
250
300
16/0
1/19
00
17/0
1/19
0018
/01/
1900
19/0
1/19
0020
/01/
1900
21/0
1/19
0022
/01/
1900
23/0
1/19
0024
/01/
1900
25/0
1/19
0026
/01/
1900
27/0
1/19
0028
/01/
1900
29/0
1/19
0030
/01/
1900
31/0
1/19
0001
/02/
1900
02/0
2/19
0003
/02/
1900
04/0
2/19
0005
/02/
1900
06/0
2/19
0007
/02/
1900
08/0
2/19
0009
/02/
1900
10/0
2/19
0011
/02/
1900
12/0
2/19
0013
/02/
1900
14/0
2/19
0015
/02/
1900
16/0
2/19
0017
/02/
1900
18/0
2/19
0019
/02/
1900
date
[NO
x] p
pb
NOx obs
NOx UAM
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)