An evaluation of pollutant dispersion and deposition ...events.awma.org/IUAPPA/presentations/11A/2010-A-158-IUAPPA_Feiz... · An evaluation of pollutant dispersion and deposition

An evaluation of pollutant dispersion and deposition models downwind from a traffic line (# 158)

Amir Ali Feiz*, Benjamin Loubet, Fabrice Dugay, Cécile Honoré, Brigitte Durand and Pierre Cellier

* INRA Grignon INRA GrignonEquipe Biosphère-Atmosphère (BioAtm)

UMR 1091 Environnement et Grandes Cultures (EGC)78850 Thiverval-Grignon, France

{amir.feiz, benjamin.loubet}@grignon.inra.fr

A L I M E N T A T I O N A G R I C U L T U R E

E N V I R O N N E M E N T

15th IUAPPA World Clean Air CongressVancouver, September 12-16, 2010

1

Environmental Issues: Ecological context (1) What types of emissions can be observed?

Traffic is a major source of (CITEPA, 2009):

– Nitrogen Oxides (NOx) – forms when fuels are burned at high temperatures (more than 50% is emitted nationwide)

– Particulate Matter (PM) – some of these particles are emitted in vehicle exhaust, while others are formed in the atmosphere through chemical reactions between the various pollutants found in exhaust (more than 16% of the total particulate matter emissions are related to road traffic))

• 20% PM10 (Dust), 25% PM2.5

– Heavy Metals (HM) – are emitted by traffic in smaller quantities than NOx. Copper (C ) i th i HM itt d b t ffi th 50% f C i i f t ffi(Cu) is the main HM emitted by traffic: more than 50% of Cu is coming from traffic in France. Other metals emitted in smaller quantities are, e.g. Zn, Fe, Cd, As, Pt, Pd, Rh.




2

Environmental Issues: Ecological context (2) PM emission contributions?

PM emissions from traffic can be divided into three main groups:

– Direct exhaust emissions that are predominantly found in the fine fraction (PM2.5) and are documented in different emission databases (e.g. COPERT, …)

Di t i i th th h t i i f b k d– Direct emissions other than exhaust: emissions from brakes wear and clutches are emitted in roughly equal amounts in the fine and coarse (PM10-PM2.5) fraction and correlate well with the direct emissions and other vehicle emissions e.g. NOx

– Re-suspended PM emissions which arise from road abrasion, tyre wear androad dust that are found partly in the fine fraction and mostly in the coarsefraction. This PM source is often less correlated with the exhaust emission due tofraction. This PM source is often less correlated with the exhaust emission due toan influence from “external factors” such as road condition (wetness, salting,sanding, road material), use of studded tyres and climatic conditions (rain,turbulence). This PM source is also more difficult to model.




3

In the vicinity of most cities, and in particular near Paris, agricultural fieldsare intricated in the traffic lines This may lead to a potential increaseof pollution load onto local agricultural production

Objective

of pollution load onto local agricultural production

– to lay out a comprehensive field study in order to characterize the influence oftraffic-generated emissions on the temporal and spatial variability of air pollutantconcentrations in the near-road environmentconcentrations in the near road environment

– to evaluate the deposition of pollutants near heavy traffic lines under differentenvironmental conditions

⇒ A French national project was started in 2008 to: • evaluate the perception of farmers and consumers on this type of pollution• propose indicators of impact distances of the road pollution




4

… based on using dispersion models to interpret air quality measurements made close to the road

The impact distances are evaluated by comparing the results of three local dispersion

How?

The impact distances are evaluated by comparing the results of three local dispersionand deposition analytical models:

• FIDES-2D (Godson solution of the advection-diffusion equation, INRA, Loubetet al., 2001 and 2009)

• ADMS Urban (Gaussian dispersion model , CERC, 2001)• CALPUFF (Gaussian puff dispersion model, U.S. EPA, 2008)

And also by:And also by:* using the models to estimate dry deposition (dry deposition schemes of atmosphericPM are incorporated into the models)* comparing the simulations to measured concentrations and deposition rates




5

Domain study and measurement campaign

The experiment took place in the south of Parisnear the A6 highway between 15 Septemberand 13 October 2008. The average traffica d 3 Oc obe 008 e a e age a cintensity at the site was 73200 vehicles perday (DIR-IDF-2007) with 10300 trucks

Farm buildingsfields wood

Farm buildingsFarm buildingsfields wood

NOx and PMmeasurements

Deposition plates and plants

4 m 116 m284 mhig fields



4 m 116 m284 mhig



4 m 116 m284 m



4 m 116 m284 mhig fields

Met stationSonic anemometerCO2 fast sensor

Sonicanemometer

Farthest site andWet deposition

ghway

fields


Sonicanemometer


ghway Met station

Sonic anemometerCO2 fast sensor

Sonicanemometer



Sonicanemometer


ghway

fields

The NOx and PM measurements were performed along the black line. The red lines show thelocations of the plants and inert plates (at downwind receptors ranging from 9-m to 284-m from thed f th d




6

edge of the road

Experimental setup by AIRPARIF and INRAWetWetdeposition

NOPM10 PM2.5NO Sonic anemometerNO2

passive samplerNOxHAP

PlantsSoil

Inert Samplers

A6 highway : 73200 vehicles per day, 10300 trucks




7

Samplers

Experimental details (1)

Lolium perenne grown in a greenhouse and

Soil from the T t h t

greenhouse and hand watered

Soil from the same bag

Transparent sheet with silicon grease protected for rain

Analysis for Fe Analysis for FeAnalysis for Fe, Cd, Cr, Co, Cu, Zn, Ni

Analysis for Fe, Cd, Cr, Co, Cu, Fe, Mg, Pb, Zn, Ba

Analysis for Fe, Cd, Cr, Co, Cu, Fe, Mg, Pb, Zn, Ba




8

Experimental details (2)

Table 1. Overview of the measurement performed during the experiment, the distances and the period covered. Measurements Distances downwind from the road (m) Equipement Period

nb 4 9 16 27 38 57 116 284

NO and NO2 x x x x ThermoEnvironment 15 min

NO2 x x x x x x x Passive samplers weekly

PM10 & PM2.5 x x TEOM 15 min

Atmos. Cu (PM) x Partisol weekly

Raygrass deposition 5 x x x x x x x x plants in pots 4 weeks

Inert samplers dep. 3 x x x x x x x x plastic sheets & grease 4 weeks

Soil samples 3 x x x x x x x x Sampling equipement -

Turbulence x x Gill R3 and R2 30 min

Meteorological data x Meteorological mast 30 min

Wet deposition x Glass rain collector weekly




9

Deposition at 16 and 284 m

1E-3

1E-2

1E-1

µg m

-2 s

-1)

plastic sheetsplantssoil

1E-5

1E-4

1E 3

epos

ition

(µ

16 m1E-6 de

1E-2

1E-1

1E+0

m-2

s-1

)

wet depositionplastic sheets284 m

1E 5

1E-4

1E-3

1E 2

ositi

on (µ

g Lolium perenne284 m

1E-6

1E-5

Cd Cr Co Cu Fe Mg Pd Pl Pb Rh Zn Ba

Dep




10

The modelling system

meteorological pollutants species emissionmeteorologicalconditions

pollutants species(gases/particulate)

emission scenarios (COPERT)

FIDES

DISPERSION & DEPOSITION MODELS

CALPUFF ADMS

gas or particulate deposition velocity (Vd)

pollutants concentrationgases/particulate

pollutants deposition gases/particulate




11

Modelling approach (1)

3

In the atmosphere

FIDES (Flux Interpretation by Dispersion and Exchange over Short-range) is designed (Loubet et al., 2001) to allow

Deposition (μg.m-2.s-1)C (μg.m-3)

Pollution emitting source

simple and fast estimation of gases or particles dispersion and exchange over the short-range, with a mechanistic

h It i “fl t t i ”

Emission source length

approach. It is a “flat terrain” model which therefore cannot deal with change in surface roughness.

FIDES combines two submodels:

• Dispersion submodel. This submodel corresponds to the Huang (1979) 2D dispersion model:

⎥⎦

⎤⎢⎣

⎡

⋅+

−⋅

=xcZZ

xAQC(x,z)

αs

α

β exp

(1979) 2D dispersion model:• Canopy gas exchange submodel. Thissubmodel follows the resistance analogy forcanopy exchange of Sutton et al. (1995)

• Canopy aerosol exchange submodel.Dry deposition includes gravitational settlingas a function of particle size and air viscosity.

or




12

Modelling approach (2)Dry deposition modelling

zo

zo'

Particulate module

In CALPUFF, the deposition is calculated as the product of the concentration at Zo=2 mheight times the deposition velocity at that heightIn FIDES and ADMS, the concentration at Zo’ is used to evaluate the deposition flux, whichleads to larger deposition rates near the source and an overall larger deposition.




13

g p g p

Modelling approach (3)

As FIDES model, a full resistance model is provided in CALPUFF and ADMS for the computation of dry deposition rates of gases and particulate matter as a function ofcomputation of dry deposition rates of gases and particulate matter as a function of geophysical parameters, meteorological conditions, and pollutants species.

• For Gases, the deposition velocity is:

where, Ra is the atmospheric resistance (s/m) through the surface layer, Rb is the deposition layer resistance (s/m), and Rc is the canopy (vegetation layer) resistance (s/m).

cbaRd RRv

++=

1

• For Particulate Matter, the deposition velocity is:

where vs is the gravitational settling speed (m/s) of the particle.

ssbaba

d vvRRRR

v +++

=1

The dry deposition velocity, which varies with particle diameter, depends on Ra theaerodynamic resistance of mass transfer by turbulent diffusion and surface resistance,Rb the capturing capacity of surface, and the sedimentation speed vs which representsthe combined effects of gravitation and friction on a particle in a motionless air.




14

Models inputCommon parameter values used for models calculations

For each particle size or typeof gases (Rc), the parametervalues to calculate vd with themodels is used




15

Meteorological conditions10%Nord

>4 m/s ]2-4] m/s ]0-2] m/s

0%

5%

EstOuest

Sud

Correctwindsector

Bad wind sector for first part of experiment




16

experiment

Results: Models-measurement comparison (1)

600700

NO

x

Time series of NOx concentrations at 10 m and 120 m from the road

200300400500600

ntra

tions

en

N(µ

g/m

3)

ADMS-Urban CalpuffMesure FIDES

w

0100200

Con

cen

500

NO

x

200

300

400

ntra

tions

en

N(µ

g/m

3)

0

100

15/09/0820/09/08

25/09/0830/09/08

05/10/0810/10/08Heures

Con

ce




17

Heures

Results: Models-measurement comparison (2)Time series of NO2 concentrations at 10 m and 120 m from the road

300

NO

2

ADMS-Urban Calpuff

100

200

entra

tions

en

N(µ

g/m

3)

Mesure FIDES

0Con

ce

300

NO

2

ADMS-Urban Calpuff

100

200

ntra

tions

en

N(µ

g/m

3)

pMesure FIDES

015/09/08

20/09/0825/09/08

30/09/0805/10/08

10/10/08

Con

ce




18

8 8 8 8 8 8Heures

Results: Models-measurement comparison (3)Variation of NO2 concentrations with the distance to the road

50

35

40

45 MesureADMS-UrbanCalpuff

FIDES

In generally, FIDES and CALPUFF

20

25

30

NO

2] e

n µg

/m3 FIDES C U

underestimate the NO2 concentration because the

5

10

15

[N

Week 3

conversion reactions NO+O3→NO2 are not take

0

5

0 20 40 60 80 100

120

140

160

180

200

220

240

260

280

300

320

Distance de l'axe (m)

into account in these models.




19

Results: Models-measurement comparison (4)

100

120

)


Time series of PM10 concentrations at 10 m and 120 m from the road

40

60

80

PM10

(µg/

m3 Mesure FIDES

0

20

P

100

120

)


40

60

80

100

PM10

(µg/

m3 Mesure FIDES

0

20

15/09/0820/09/08

25/09/0830/09/08

05/10/0810/10/08

Heures

P




20

Heures

Results: Models-measurement comparison (5)Time series of PM2.5 concentrations at 10 m and 120 m from the road

10 m100

120

3)


40

60

80

PM

2.5

(µg/

m Mesure FIDES

0

20

120 m100

1200

40

60

80

100

M2.

5 (µ

g/m

3)

0

20

15/09/0820/09/08

25/09/0830/09/08

05/10/0810/10/08

PM




21

Heures

Results: Models-measurement comparison (6)A comparison of the deposition according to FIDES model for each

size of particles and HMs measured3.0E-043.5E-044.0E-04

2 s-

1)

20 µm5 µm1.25 µm0 31 µm 1.6E-05dZn < 5 µm

0.0E+005.0E-051.0E-041.5E-042.0E-042.5E-04

dépô

t (µg

m-2 0.31 µm

0.08 µm0.02 µmZinc (µg m-2 s-1)

4.0E-066.0E-068.0E-061.0E-051.2E-051.4E-05

dépô

t (µg

m-2

s-1

) Plomb (µg m-2 s-1)

dZn 5 µm

1.5E-05

2.0E-05

2.5E-05

3.0E-05

3.5E-05

t (µg

m-2

s-1

) Chrome (µg m-2 s-1)

0.0E+002.0E-06

2.5E-043.0E-043.5E-044.0E-04

-2 s

-1) Cuivre (µg m-2 s-1)

d 50.0E+00

5.0E-06

1.0E-05

dépô

t

5 0E-06

6.0E-06 0.0E+005.0E-051.0E-041.5E-042.0E-042.5E 04

0.00 20.00 40.00 60.00 80.00 100.00 120.00dé

pôt (

µg m

- dcu < 5 µm

1.0E-06

2.0E-06

3.0E-06

4.0E-06

5.0E 06

dépô

t (µg

m-2

s-1

) Cadmium (µg m-2 s-1) x (m)

Pb, Cr and Cd dominated by re-suspended matter rather than emissions from vehicles




22

0.0E+00 than emissions from vehicles

Sensitivity studies: Model-model comparison (1)Sortie C50

2

2.5

yenn

e

FIDES

Sentitivity of simulated concentrationsGasat 50 m from the road

0

0.5

1

1.5

L (Longueur WD (Direction Zo (Hauteur de Lemi (Largeur hsrc (Hauteur Type de gaz

Sens

ibili

té m

oy CALPUFF

ADMS-Urban

( gMonin

Obukhov)

(du vent)

(rugosité)

( gde la route)

(de la source)

yp g

Sortie DC50Sentitivity of simulated cumulated depositionGasat 50 m from the road

0.2

0.3

0.4

0.5

0.6

bilit

é m

oyen

ne

FIDES

CALPUFF

ADMS Urban

at 50 m from the road

0

0.1

L (LongueurMonin Obukhov)

WD (Direction duvent)

Zo (Hauteur derugosité)

Lemi (Largeur dela route)

hsrc (Hauteur dela source)

Type de gaz

Sens

ib ADMS-Urban




23


2

2.5

yenn

e

FIDES

Particles(dp=20; 5; 1.25 µm)

Sentitivity of simulated concentrationsat 50 m from the road

0

0.5

1

1.5

L (Longueur WD (Direction Zo (Hauteur Lemi (Largeur hsrc (Hauteur Type de

Sens

ibili

té m

oy CALPUFF

ADMS-Urban

MoninObukhov)

du vent) de rugosité) de la route) de la source) particule(taille)

Sortie DC50Particles(dp=20; 5; 1.25 µm)

Sentitivity of simulated cumulated depositionat 50 m from the road

16.0000

24.0000

32.0000

40.0000

bilit

é m

oyen

ne

FIDES

CALPUFF

ADMS-Urban

( p µ ) at 50 m from the road

0.0000

8.0000


WD (Directiondu vent)


Lemi (Largeurde la route)

hsrc (Hauteurde la source)

Type departicule (taille)

Sens

ib




24

l10

Slide 24

l10 idem page précédenteloubet, 9/3/2010


2

2.5

yenn

e

FIDES

Particles(dp=0.31; 0.08; 0.02 µm)

Sentitivity of simulated concentrationsat 50 m from the road

0

0.5

1

1.5

L (Longueur WD (Direction Zo (Hauteur Lemi (Largeur hsrc (Hauteur Type de

Sens

ibili

té m

oy

CALPUFF

ADMS-Urban

MoninObukhov)

du vent) de rugosité) de la route) de la source) particule(taille)

Sortie DC50Particles(dp=0.31; 0.08; 0.02 µm)

Sentitivity of simulated cumulated depositionat 50 m from the road

0.8

1.2

1.6

2

bilit

é m

oyen

ne

FIDES

CALPUFF

ADMS-Urban

( p µ ) at 50 m from the road

0

0.4


WD (Direction duvent)


Lemi (Largeur dela route)

hsrc (Hauteur dela source)

Type de particule(taille)

Sens

ib




25

Sensitivity studies: Model-model comparison (5)

10

100

e dé

pôt

L WD Zo Lemi hsrc Part1, Part2, Part3

ADMSCumulated deposition of particulate pollutants (dp=20; 5; 1.25 µm)

100


0.01

0.1

1

Sens

ibili

té m

oyen

ne (s

ur l

cum

ulé)

CALPUFF

( p ; ; µ )

0.1

1

10

té m

oyen

ne (s

ur le

dép

ôt

cum

ulé)

0.0015 10 20 50 100 200 300 400 500

Distance en aval de la source (m)

S


CALPUFF

0.001

0.01

5 10 20 50 100 200 300 400 500


Sens

ibili

t

0.1

1

10

100

oyen

ne (s

ur le

dép

ôt

cum

ulé)

FIDES

0.001

0.01

5 10 20 50 100 200 300 400 500


Sens

ibili

té m

o




26

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l12 voir remarque précédenteloubet, 9/3/2010

Final comments

Analysis of models results provided clues for understanding of pollution road impacts on agricultural production!

Simulated NOx and PM10 concentrations are close to those measured. Measured traffic level could improve the models results.

Heavy metal deposition simulated by CALPUFF ADMS are lower than

B h d li d i l l h i d i i

Heavy metal deposition simulated by CALPUFF, ADMS are lower than measured deposition => Measurements include the resuspension of material from other sources.

Both modeling and experimental results show two important driving forces of deposition: particle size and friction velocity (wind speed, Monin-Obukhov length and surface roughness).

The sensitivity studies shows that the deposition is in ascending orderinfluenced by the type of pollutant, thermal stratification, wind direction, height source, roughness length and finally by the source width.




27

Thank you for your attention!

Contact information: [email protected]




28

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An evaluation of pollutant dispersion and deposition ...events.awma.org/IUAPPA/presentations/11A/2010-A-158-IUAPPA_Feiz... · An evaluation of pollutant dispersion and deposition