Croucher Advanced Study Institute 2011-2012 Urban Climatology for Tropical & Sub-tropical Regions
Modelling Urban Air Quality using the Street Scale Resolution Atmospheric Dispersion Model ADMS-Urban
• David Carruthers • Technical Director • Cambridge Environmental Research Consultants
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Contents
• Introduction • Examples of model performance • Modelling methods • ADMS-Urban features • Application of ADMS- Urban in London and Beijing •Nesting of ADMS-Urban in a regional air quality model
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
1 London smog 1952
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Chang An Avenue Beijing in 1979
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
2 Pollution sources in China
Industrial Sources 工业污染源 Traffic in Modern Beijing Inner Mongolia 现代北京的交通
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Same place, different days...
Good Worse Bad
BBC 2008
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
3 Impacts of Air Pollution • Serious health effects - mainly respiratory: -estimated 35,000 premature deaths in Europe per year due to particulate pollution; -10% Beijing population have some respiratory problems; -estimated (GAINS ASIA model) average of 40 months loss of life expectancy per person in China due to particulate pollution; -cost to economies of lost work days and of health care; • Impacts on natural environment - affects plant growth, crop yield, water quality etc. • Visibility impairment
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Examples of air quality model performance in urban areas
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
4 From DEFRA model inter-comparison exercise (D Carslaw)
• NOx
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
From DEFRA model inter-comparison exercise (D Carslaw)
• NO2
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
5 From DEFRA model inter-comparison exercise (D Carslaw)
• PM10
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Modelling methods
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
6 Factors affecting air quality in urban areas
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Modelling Methods Box models - uniform concentration in each box
Gaussian type models - assumed concentration distributions
simple ISC (point sources) CALINE (traffic) advanced ADMS (4, Urban) AERMOD AirQUIS OML Puff Models eg CALPUFF, SCIPUFF, RIMPUFF
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
7 Modelling Methods cont’d Particle models - Stochastic or random walk models calculate trajectories of large number of particles as series of steps eg NAME (UK Met Office), AUSTAL (Germany)
Complex numerical models Steady state (CFD) computational fluid dynamics – eg eddy diffusivity models; Reynolds stress Time dependent – Large Eddy Simulations, Chemical Transport Models eg MM5 or WRF and CMAQ
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
ADMS-Urban features
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
8 ADMS-Urban Model Capabilities I
. ADMS-Urban is designed to model dispersion scenarios of varying complexity, from a single isolated industrial site or road to multiple industrial, domestic and road traffic emissions over a large urban area
. Fully integrated street canyon model based on Danish OSPM model
. Local and regional NOX chemistry calculation (NO, NO2 and O3)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
ADMS-Urban Model Capabilities II
. Based on current understanding of atmospheric boundary layer. A dispersion model in which the boundary layer structure is characterised by the height of the boundary layer and the Monin-Obukhov length . A non-Gaussian vertical profile of concentration in convective conditions . A meteorological pre-processor – flexible input . Models the effect of complex terrain (hills) . Calculates emissions from traffic flows or accepts calculated emissions
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
9 ADMS-Urban Model Capabilities III
. Integration with Geographical Information Systems (GIS) and an Emissions Inventory Database (EMIT) . Output via GIS includes high resolution pollutant concentration maps . Can consider Air Quality Management and Mitigation Options e.g. Low Emission Zones, Technical Options, Traffic management. . Used in many major cities, for example: London, Birmingham, Budapest, Rome, Beijing, Shanghai, Hong Kong
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Modelling a plume from a point source I Q y2 (z z ) plume s exp exp s ~ U 2 2 y z 2 y 2 z Includes chemistry schemes
U* z z0 wind U ~ ln e.g. oxides of nitrogen & sulphate z0
plume (motion ) (turbulence ) rise entrainment ~ Ue Ue dry and c,v c dx d p u t wet ~ dt p surface deposition d roughness z0 | u p | dt changes
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
10 Modelling a plume from a point source II 1 hourly concentration of NOx in µg/m³ 800
600
400 400
350 200
s 300
e source r t 0
e 250 M -200 200
150 -400 100
-600 50
-800 0 500 1000 1500 2000 Metres
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Road and other source types including roads
• Integrate point sources to model line sources • Integrate line sources to model volume sources • Add a crosswind exit velocity to model jet sources • Include traffic-induced turbulence and the effect of street canyons to model road sources
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
11 Stages in the analysis of dispersion close to a building
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Modelling flow over hills I – semi analytic approach 2 Regimes: • Moderately stable, neutral or convective meteorological conditions inviscid flow stratification outer layer important
wind middle layer shear important
shear stresses inner dominate layer
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
12 Modelling flow over hills II 2 Regimes: • Very stable meteorological conditions (“Froude Number < 1”) U (h) Froude _ Number N(h)h hmean dividing ~ exp X 2 Y 2 wind surface 3-layer flow over the hill
smoothing h
potential flow around the hill
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
• GRS Chemistry Scheme Modelling NOx and NO2 (1) (2) . Venkatram A. et al “The Development (3) and Application of a (4) Simplified Ozone (5) Modelling System”, (6) Atmospheric (7) Environment, Vol (8) 28, No. 22, pp 3665- 3678, (1994) where ROC = Reactive Organic Compounds RP = Radical Pool SGN = Stable Gaseous Nitrogen products SNGN = Stable Non-Gaseous Nitrogen products
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
13 Modelling road traffic sources – Local effects
– Street canyons/ building effects – Vehicle induced turbulence – Initial mixing depth – exhaust height and buoyancy
– Tunnels, embankments, cuttings, flyovers, noise barriers – Different vehicle mixes in different lanes – Queues – Different speeds in different directions – Road gradients – Bus stops, Bus stations – Car parks
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Street canyons
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
14 Street Canyons Estimated street canyon heights for Central London
Street canyon MSI coverage height (m) N 0 Geo-Information coverage 0 - 10 10 - 15 0 3 6 Kilometers 15 - 20 20 - 35 Mapping data - O rdnance Survey 1:50000 C olour Raster Data (c) C rown C opyright
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Street canyons wind
building heights recirculation region
detailed emission factors
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
15 Street canyons
Table 1
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Street canyons • Street canyon modules (eg OSPM used in ADMS) • Currently: – 2-dimensional solution used within the canyon • Possible improvements: – Model end effects (junctions) – Have some account taken of effect of street canyon externally (similar to noise barriers) – Model asymmetric canyons – Model multiple re-circulation regions for tall thin canyons
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
16 Vehicle induced turbulence
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Vehicle produced turbulence - FLOW and TKE Two-way traffic v /u(4H) u /u(4H) v /u(4H) 1.0 1.0 1.0
0.8 0.8 0.8
0.6 0.6 0.6
H / z 0.4 0.4 0.4
0.2 0.2 0.2
0.0 0.0 0.0 -0.5 -0.3 -0.1 0.1 0.3 0.5 -0.5 -0.3 -0.1 0.1 0.3 0.5 -0.5 -0.3 -0.1 0.1 0.3 0.5 1.0 1.0 1.0
0.8 0.8 0.8
0.6 0.6 0.6
H / z 0.4 0.4 0.4
0.2 0.2 0.2
0.0 0.0 0.0 -0.5 -0.3 -0.1 0.1 0.3 0.5 -0.5 -0.3 -0.1 0.1 0.3 0.5 -0.5 -0.3 -0.1 0.1 0.3 0.5 x/H x/H x/H Along-canyon flow component One-way traffic
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
17 Vehicle produced turbulence – Dispersion
c* cUHLs Es
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Vehicle-induced turbulence Results ADMS-Urban: annual average concentrations High speed Urban area Z0 = 0.75m Road 140
120 Low flow Medium flow 100 High flow 80
60
40
20 Normalised concentration 0 -30 -20 -10 0 10 20 30 Distance from road centre (m)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
18 Initial Mixing depth Effects of exhaust height and buoyancy
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Dispersing vehicle exhaust
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
19 Initial Mixing – Exhaust Location Impacts
5(c) Low level exhaust 50km/hr 5(d) High level exhaust 50km/hr Car 6 Lorry horz 40 Van 5 Lorry 45 deg Bus Lorry vert 30 4 Lorry horz 3 20 2
10 NOxconc (ug/m³) NOxconc (ug/m³) 1
0 0 0 10 20 30 40 0 10 20 30 40 Distance dow n stream (m) Distance dow n stream (m)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Initial mixing height in model
• Consider – Height of line source that represents the road – Initial vertical plume spread parameter
Initial mixing height parameter
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
20 Initial mixing height ADMS-Urban: annual average concentrations Road 450 400 1m 350 300 2m 250 200 3m 150 100 50 Concentration (µg/m³) 0 -200 -100 0 100 200 Distance from road centre (m)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Other features near roads
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
21 Tunnels • Tunnels – User enters traffic flows and speeds within the tunnel – Emissions modelled as volume sources at tunnel exits – Account taken for venting of emissions from tunnel?
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Flyovers ………………… etc • Flyovers – Effectively an elevated line source, shielded underneath
Model effect on concentrations at ground level No calculations of concentrations below the flyover
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
22 Modelling Issues • Cuttings Road source attributes – NOT appropriate to model as complex terrain – Similarities to street canyon module – Account for asymmetry? Model effect on Are concentrations concentrations at within the cutting of ground level interest?
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Modelling Issues • Embankments Road source attributes – NOT appropriate to model as complex terrain – Effectively an elevated line source, shielded underneath Are – Account for asymmetry? concentrations on the Model effect on embankment of concentrations at interest? ground level
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
23 Noise barriers
Noise Barriers–modelled using ADMS-Urban/Roads (barrier 5m) 200
Noise barrier
150
No barrier With barrier 100
Concentration (µg/m³) Concentration 50
0 0 10 20 30 40 50 60 70 80 90 100 Distance from Road Centre (m)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Application of ADMS-Urban in London and Beijing
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
24 Modelling emissions in large urban areas
# # ## # # # # • Emission sources in London # # # # # # # # # # # ## # # ### ## # # # # ## # # # # # # # # # # ## # ## # ## # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ## # # ## # # # # # # # # # # # # # # # # # # # # # # # # # ## # ## # # # ## # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ## # # # # # # # # # ## ## # ## # # ## # ## # # # # # # # # # # # # # # # # # # # ## ## # # # # # # # # # # # # # # # ## # # # # # # # # # # ## # # # # # # # ## # ### # # # # # # # # # # # # # # # # # # # # ## ## ## ## # # # # # # # # # # # # # # # ## # # # # # # # # # # # ### # ### # # # # # # # # # # # # # # # # # # # # # # # # ## # # # # # # # ## # # # # # # # # # # # # # # # # # # # #### # ### # # # # # ## # # # # # ## # # # # # # # # # ## ## # # # # # ## # # # # # # ## # ## # ## # # # # # # # # # # # # # # # # # # # # # ###### # # # # # # # # # # # # # # # # # # # # #### # # # # # ## # ## # # # # # ## # # # # # # # ## # # # # # ## # # # # # # # # ## # # # # # # ## # # # # ## # # # # # # ## # # # # # # # # # ### # ## ## # # # # ## # # # ## # # # # ## # # # # # #### # # # # # # # # # # # ## # # # # ## ### # ## # ### # # # # # # # ## # # # ## # # # # # # # # # # # # # # # # # # # # # # # ## # # # # # # # # # # ## ### # ## # ### ## ### # # # # # # # # # # # # # ## ### # # # ## # # # # # # # # # # # # # # ## # # # # # # # # ## # # # # # # # # # # # # # # ## # # # # # # ## # ## # # ## # # ## ## # # ## # # # # ## ## # # # # # ## # # # ### # ## ### # # # # # # # # # # # ### # # # # # # # # # # # # # # # # # # # # # # # ## ## # # # ## # # # # # # # # # # # # # # ## # # # # # # # # # # # # # # # # # # # ## # # # # # # # # # # ## # # # # # # # # # # # ## # # ## # # # ## # # # # # ### # ## # # # ## ## ## # ## # # # # # # ## # # ## # # # ## # # # ## # ## # # # # ## # # # # # # # # # # # # # # # # # # ## # # # # ## # # ## ## # # # # # ## # # # # # # # # # # # ## # ## # # ## # # # # # ## # ## # # # ## # # # # # # # # # # ## # # # # # # # # # # ### # # # # ## # # # # # # # # # # # # # # # # # # ## # # # # # # # ## ### # # # # # # # # # #### # # # # # # # # # ## # # # # # # # # # # # # # # # ## # # # # # ## # # # # # # # # ### # # # ## # # # # # # # # ## # # # ## # # ## # # # ## # # ## # # # # # # # # # ### ## # # # # # # # # # # # # # # # # # # # # # # # ### # # # # # # # # # # ## # # # # # # ## # # # # # # # # # # # # ## # # # # ## ## # # # # # ## # # # # # # # # # # # # # ## # ### # # # # # # # # # # # # # # # # # # # ## # # # # # # # ### # ### # ## # # ## #### # # # ## # # ## # # # # # # # # # # # ## # # # ## ## # # # ## # # # # # # # # # ## # # # # # # # # ## # # # # # ## # # ## # # ## ## # # # # # # # # # # # ## # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ### # # # # ## # # # ### # # # ## # # # # # # # # # # ## # # # # # # # # # # # # # # # # # # ## # # # # # # # ## # #
# ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
ADMS-Urban - Local and Regional Scales
Box model domain
Main model domain
First source
Backgound monitoring site
U • Main model nested with large, area-wide trajectoryFigure 2 Schematic model showing the main model nested within large area-wide box model.
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
25 Investigation Process
Emission Air Quality Measurements Measurements
Understand Source/ Control Options - Emission Dispersion Concentration Costs and Emission Relationship Reductions Inventory Model Estimate Damage
Other data Other data
Compare and Select Options
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Assessment of Air Quality - London Emissions Monitoring network Y# Y# Y# Y# Y# Y# Y# Y# Y# Y# Y# Y# Y# #Y Y# Y# Y# Y# Y# Y# # Y#Y# #Y Y# Y# Y#Y# Y# Y# Y# Y# # Y# Y Y# Y# # Y# Y# Y# #Y #Y Y# #Y Y#Y# # Y# Y# Y# Y#Y#Y Y# Y# Y# Y# Y# #Y #Y Y# Y# Y# #Y Y# Y# #Y Y# Y# Y# #Y Y# Y# Y# #Y Y# Y# # Y# Y# Y# Y Y# Y# Y# Y# #Y Y# Y# Y# Y# Y# Y# Y# Y# Y#
Y# #Y Y# # Y# #Y Y# Y# LAQN Sites Y# Y# #Y Y# #Y AURN sites Y# # Y# Y
Y#Y#
0 20 40 60 Kilometers
0 5 10 20 30 Kilometers
N O 2 (µg/m ³) N O 2 ( µ g / m ³ ) > 56 > 5 6 52 - 5 6 5 2 - 5 6 48 - 5 2 4 8 - 5 2 44 - 4 8 4 4 - 4 8 40 - 4 4 4 0 - 4 4 36 - 4 0 3 6 - 4 0 32 - 3 6 3 2 - 3 6 28 - 3 2 2 8 - 3 2 24 - 2 8 2 4 - 2 8 20 - 2 4 2 0 - 2 4 < 2 0 < 20
F ig u r e 6 .4 F i g u r e 4 .1 b
L o n d o n 2 0 0 1 L o n d o n 2 0 1 0 - 2 0 % N O 2
A n n u a l a v e r a g e N O 2 c o n c A n n u a l a v e r a g e N O 2 0 5 1 0 K i lo m e t e r s Modelled annual average NO2: 2001 and 2010 ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
26 London: Source apportionment With ADMS-Urban
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
2010 Low emission Zone (LEZ) Reductions in PM10 at Receptor Points
25 Base case LEZ 1: HGVs & non TfL buses base 2 LEZ 2: HGVs, non TfL buses, LGVs & LEZ 2 LEZ 1
24 taxis
)
3 g/m
23
22
Concentration Concentration ( 21
20
190
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
27 Modelled NO2 concentrations at London Heathrow Airport 2002 Base Case 2010 SM 2015 SM
181000
80 180000
70 179000 60
178000
50
)
s
e
r t
e 177000 m
( 40
g
n
i
h
t r
o 176000 35 N
175000 30
20 174000
10 173000 0
503000 504000 505000 506000 507000 508000 509000 510000 511000 512000 Easting (metres) 20150 2000 MM4000 6000 8000 2020 R3 2030 R3
181000
80 180000
70 179000 60
178000
) 50
s
e
r t
e 177000
m
(
s 40
g
n
i
h
t r
o 176000
N 35
175000 30
174000 20
173000 10
0 503000 504000 505000 506000 507000 508000 509000 510000 511000 512000 Eastings (metres)
0 2000 4000 6000 8000
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Beijing’s air quality: emission controls .Control of energy and industrial production, construction and transport;
.Final (Olympic) stage on 20 July 2008 - reduction in the use of private cars further Green sticker for Euro I (III) reduction in the use of government cars; Vehicles restricted to operating or above for on alternate days according to petrol (diesel) whether the final number on vehicles .a temporary halt to construction during the their licence plate is odd or even Olympic period;
.more cleaning of the roads to reduce dust
.the suspension of heavily polluting industry;
Signs alert drivers to areas of congestion and inform if the Higher polluting vehicles .a reduction in production for coal-based roads are free flowing banned on urban roads from 1 enterprises. July to 20 September - no yellow stickers
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
28 Beijing’s air quality: emission controls Forecasted and monitored API in Beijing ADMS-Urban in hindcast mode 200 ADMS-Urban (average = 82) MEP (average = 68) EPB (average = 66)
150
100 API indexAPI
50
0 05/07 15/07 25/07 04/08 14/08 24/08 03/09 13/09 With emission reduction2008 measures Forecasted and monitored API in Beijing ADMS-Urban in hindcast mode, no emissions reduction after 19 July 200 ADMS-Urban (average = 110) MEP (average = 68) EPB (average = 66)
150
100
API indexAPI Beijing air quality forecasts 50
0 Number of blue sky days 05/07 15/07 25/07 04/08 14/08 24/08 03/09 13/09 2008 increasing; concentrations Without emission reduction high by European standards measures (black line)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Nesting ADMS-Urban within a regional model
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
29 Nesting ADMS-Urban in a regional model - Motivation • Why nest a local model within a regional model? • What are the advantages of a nested model?
Model feature Model Regional (eg grid based) Local (eg Gaussian plume) Domain extent Country (few 1000 km) City (50km) Meteorology Spatially and temporally Usually spatially varying from meso scale homogeneous models Dispersion in low wind Models stagnated flows Limited modelling of speed conditions correctly stagnated flows Deposition and Reactions over large spatial Simplified reactions over chemical processes and temporal scales short-time scales Source resolution Low High Validity Background receptors Background, roadside and kerbside receptors
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
CMAQ/ADMS-Urban nesting system
• Aim: to nest local model in regional model without double counting emissions i.e.: Gridded Explicit Concentration Regional locally locally within nested = modelling of - modelled + modelled domain emissions emissions emissions (ΔT) (ΔT) ΔT is the time taken to mix the explicitly defined emissions to produce a concentration field that varies spatially on the same scale as the regional model
ΔT varies with meteorology
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
30 CMAQ/ADMS-Urban nesting system MM5 meteorological data Emissions data
MCIP meteorological ADMS-Urban Meteorological data for pre-processor (modified to allow use in ADMS-Urban for truncation) CMAQ ADMS-Urban concentrations (gridded emissions, ΔT)
ADMS-Urban concentrations (explicit Urban CMAQ emissions, ΔT) background concentrations
Post-processing: Nested concentrations = CMAQ concentrations – ADMS-Urban concentrations (gridded emissions, ΔT) + ADMS-Urban concentrations (explicit emissions, ΔT)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Preliminary modelling
Model set up: NO2 emissions NO2 t/year/km2 NO2_t_year 0 - 1 ADMS explicit 1 - 3 9km 3 - 5
5 - 10 Road 10 - 13 NO2_t_year 0 - 0.25 13 - 15 0.25 - 0.45 0.45 - 1.0 15 - 18 1.0 - 1.5 1.5 - 2.5 18 - 20 2.5 - 4.0 4.0 - 6.0 20 - 25 6.0- 8.50 25 - 40 Grid NO2_t_year 6.852773 - 6.900000 6.900001 - 7.000000 7.000001 - 7.100000 0 15 30 60 Kilometers 7.100001 - 10.000000 10.000001 - 13.000000 13.000001 - 15.000000 15.000001 - 18.000000 18.000001 - 20.000000 CMAQ 20.000001 - 25.000000 25.000001 - 40.000000
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
31 Preliminary modelling
Model results: receptors – NO2 Roadside and Kerbside Background
(Summer)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
Preliminary modelling
Model results: receptors – O3 Winter Summer
(All sites)
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
32 Preliminary modelling
Model results: NO2 average contours CMAQ outer domain NO µg/m³ 9km 2
Consistency of background concentrations 1km
ADMS-Urban nested domain
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
End, Thank You
David Carruthers Cambridge Environmental Research Consultants 3 Kings Parade, Cambridge, CB2 1SJ, United Kingdom Tel: +44 1223 357773 Email: [email protected] Website: www.cerc.co.uk
ASI 2: URBAN CLIMATE AND AIR POLLUTION School of Architecture, The Chinese University of Hong Kong, Hong Kong, 7-8 Dec 2011
33