Ranjeet S Sokhi, Nutthida Kitwiroon andLia Fragkou

Atmospheric Science Research Group (ASRG)University of Hertfordshire

Modelling of Urban Air QualityUse of MM5/CMAQ and New Initiatives

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• Roberto San Jose –UPM, Spain• UK Met Office – Doug Middleton and

Pete Clark• COST 715• SATURN (EUROTRAC 2 Subproject)• FUMAPEX (EU FP5)

Collaboration

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Planetary Boundary Layer (PBL)

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• Box models – PEARL, BOXURB• Gaussian plume models – GAMMA,

ADMS, CALINE4, ISC, AERMOD …..• Numerical Eulerian grid models –

MM5/CMAQ (USEPA Models 3)• Lagrangian models – eg NAME (Met

Office)

Types of air quality models

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Meteorological pre-processor, GAMMA-MET

Solar radiation

Albedo, Bowen ratio

Anthropogenicheat

Heat into Ground

Wind speed Surface roughness

Friction Velocity (u*)

Sensible Heat (H)

TemperatureCloud cover

Monin-Obukhov length (L)

Energy budget

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Examples of Met & AQ Models

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Country Met Model AQ Model Type

UK UM NAME, ADMS, ….

LagrangianGaussian

Denmark HIRLAM DERMA Lagrangian

Germany LM, COSMO

MUKLIMOTM

EulerianLagrangian

Spain RAMS HYPACT Hybrid

Finland HIRLAM Various models Gaussian Eulerian

Italy RAMS FARM Eulerian

Norway MM5 EPISIODE/AirQUIS

Eulerian, Gaussian

Many more: AERMOD, UAM, MEMO, LPD, …..

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• Eulerian• Second- and higher- order

chemical kinetic equations• Many vertical layers• Numerical diffusion• Large computing

requirements• large grid spacing-

inaccurate representation of point sources

• Pollutant distribution on multi-spatial/temporal scales…..

• Lagrangian• Limited to a few reacting

chemical species• Single- or two-layer models• No numerical

differentiation required for mean concns

• Particle approach not tied to windfield grid

• Better representation of point sources

• Source attribution….

Comparison of Approaches

Numerical meteorological modelNumerical meteorological model Developed by the Pennsylvania State University Developed by the Pennsylvania State University

and the University Corporation for Atmospheric and the University Corporation for Atmospheric Research (UCAR) Research (UCAR)

Mesoscale and regional scaleMesoscale and regional scale Non-hydrostatic (version 3)Non-hydrostatic (version 3) Terrain-following model Terrain-following model Outputs: Outputs: 3D forecast fields: U, V, T, etc.3D forecast fields: U, V, T, etc.2D forecast fields: PBL HGT, SHFLUX, LHFLUX, u2D forecast fields: PBL HGT, SHFLUX, LHFLUX, u**, etc., etc.2D constant fields: LAND USE, TERRAIN, etc.2D constant fields: LAND USE, TERRAIN, etc.Range of visualisation toolsRange of visualisation tools

MM5

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Mesoscale Model – MM5

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MM5/CMAQ

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MM5Meteorological Modelling

System

MEPPSEmission

Modelling System

MCIPMeteorology-Chemistry

Interface Processor

ECIPEmission-Chemistry Interface Processor

LUPROCLand use Processor

ICON & BCONInitial Boundary Conditions

Processor

JPROCPhotolysis Processor

Process Analysis

Aggregation

CMAQ Chemical Transport Model (CTM)Governing EquationsPlume-in Grid TreatmentGas Phase ChemistryTransport AlgorithmsAerosol Chemistry & DynamismCloud Chemistry & Dynamism

Integration of Science Code in Models-3

Fundamentals of Dynamics for CMAQ

Program Control Processing

Planetary Boundary Layer Height (m) 11-02-2003

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MM5 Output-Sensible Heat Fluxes 11-02-2003 06.00

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MM5 Output-Sensible Heat Fluxes 11-02-2003 12.00

Atmospheric Science Research Group (ASRG)

MM5 Output-Wind Fields (m/s) 11-02-2003 12.0027

Atmospheric Science Research Group (ASRG)

Temperature Profile over London, 13/02/2003940

950

960

970

980

990

1000

1010

269.8 270 270.2 270.4 270.6 270.8 271 271.2 271.4 271.6 271.8 272

Temperature, K

Pres

sure

Lev

els,

mb

Vertical Temperature Profile, 6 AM, 13/02/2003

940

950

960

970

980

990

1000

1010

269 269.5 270 270.5 271 271.5 272 272.5 273 273.5 274

Temperature, K

Pres

sure

Lev

el, m

b

Vertical Temperature Profile, 3PM, 13/02/2003

6am

3pm

Atmospheric Science Research Group (ASRG)

CMAQ – London NO2 1x1 km

NO2 Diurnal Variation at Bloomsbury (Wednesday 14 AUGUST 2002)

0

10

20

30

40

50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour

NO

2 Con

cent

ratio

n (P

PB)

Measured Data CMAQ Output

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CMAQ – London NO2 1x1 km

NO2 Diurnal Variation at Bloomsbury (Thursday 15 AUGUST 2002)

0

10

20

30

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour

NO

2 C

once

ntra

tion

(PPB

)

Measured Data CMAQ Output

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CMAQ – London O3 1x1 kmO3 Diurnal Variation at Bloomsbury

(Thursday 15 AUGUST 2002)

0

10

20

30

40

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Hour

O3 C

once

ntra

tion

(PPB

)

Measured Data CMAQ Output

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CMAQ Vs. Measured Data(Hourly O3 Concentration at Bloomsbury)

13-17 JULY 2002Hourly O3 Concentration between 13-17 JULY 2002

0

10

20

30

40

50

60

70

1 8 15 22 29 36 43 50 57 64 71 78 85 92 99 106

113

Hour

Hou

rly O

3 Con

cent

ratio

n (P

PB)

Measured Data CMAQ Output

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Weekday Diurnal Variation in Traffic (Source TfL Sept 2002)

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0

1000

2000

3000

0 6 12 18 24Hour of the day (begining)

Num

ber o

f veh

icle

s

Commercial Road Chelsea Embankment Islington High Street Bayswater Road

Diurnal Traffic Variation at Cromwell RoadData compiled by Adrian Buckland for Aeolius

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0

0.4

0.8

1.2

1.6

0 5 10 15 20 25Hour of the day

Perc

enta

ge o

f the

wee

kly

tota

l

Wednesday Sunday

FUMAPEX Scheme (EU FP5)

Meteorological observations

Global / Regional NWP models

Limited area NWP

Meso-meteorological models (e.g. non-hydrostatic)

Local scale models

Met pre-processors/ Interfaces

Emis- sion data

Urban Air Pollution models

Population Exposure models

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Resolution: Models, e.g.:

15 km ECMWF/HIRLAM,GME

~1-5 kmLM, HIRLAM,

> 0.5 kmMM5, RAMS, LM

~ 1-10 mCFD, box models

• To evaluate the treatment of UBL processes in mesoscale models (UM New Dynamics, MM5)

• To study situations important for urban air pollution – episodes (e.g. London as a case study)

• To compare model profiles with observations where available e.g. lidar

• Using Met Office profiles from civil aircraft sensors AMDARS: temp, wind speed, direction

• Investigate secondary pollutant episodes (eg 1996, 2000) using joint Lagrangian/Eulerian evaluations…transport, emissions dynamics and chemistry schemes

Proposed Future Work

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