EvaluationofWintertimeCOandNOxEmissionsInventoriesfromtheTreasureValleyPM2.5

PrecursorStudyH.W.Wallace,M.H.Erickson,J.Vaughan,J.K.McCoskey,B.K.Lamb,B.T.Jobson

NW‐AIRQUESTAnnualMeetingApril1,2010

TreasureValleyPM2.5PrecursorStudy Goal:Tocharacterizeatmospheric

PM2.5,precursorgases,andtherelevantmeteorologyduringtypicalwintertimeconditions.

TwomonthstudyinBoise,ID. Dec.2008‐Jan.2009

Success! >90%Datacompletenessforall

buttwoinstruments. Sampledasignificantwintertime

stagnationevent.

SiteOverview

MACLLocation

ThesiteisborderedonthesouthbyI‐84.DowntownBoiseisapproximately7milestotheeastandSt.Luke’sMeridianMedicalCenterislocatedimmediatelywestofthesite.

Aerosol

ParticleSizeDistributionnanoSMPS(3‐60nm)(Assembledinhouse

withTSIcomponents)longSMPS(40‐700nm)(Assembledin

housewithTSIcomponents)APS(0.6‐20um)(TSI)

BulkSolubleCompositionParticle‐Into‐LiquidSampler–PILS

(Brechtel)Inorganics(SO4,NO3,Cl,NH4,Na,Mg,...)

byIonChromatography(Metrohm‐Peak)WatersolubleorganiccarbonbyTOC

analysis(Sievers/GEAnalytical)

CloudCondensationNuclei(DMT)AerosolSpatialVariabilityandOptical

Depth(LeosphereAerosolLidar)

Meteorology

P,T,RH,Windspeed&direction,Precip(VaisalaWXT)

BoundaryLayerHeight(LeosphereAerosolLidar)

TraceGases

Ozone(Dasibi)CarbonMonoxide(Aerolaser)NOx/NOy(AirQualityDesign)SO2(Teledyne)TimeResolvedVOCs(PTR‐MS,Ionicon)SpeciatedVOCs(notdeployedinBoise)

VarianGC‐MSCustom2‐channelVOCpreconcentrator

MACLInstrumentation

0

0.025

0.05

0.075

0.1

0.125

0.025 0.05 0.075 0.1 0.125

0

45

90

135

180

225

270

315

0 - 1 1 - 2 2 - 3 3 - 4 4 - 5 5 - 6 6 - 7 7 - 8 8 - 9 9 - 10 10 - 11 11 - 12 12+ (m/s)

WindRosePlot:

800

600

400

200

0

# IN

ST

AN

CE

S

0.12 3 4 5 6 7 8 9

12 3 4 5 6 7 8 9

10Wind Speed 2 min average, (m/s)

WXT 2 Minute Average

WindSpeedLogHistogram:

BoiseWinds

DiurnalAverageProfileofPBLHeightandAerosolOpticalDepth,Dec‐Jan

NormalizedresidencetimeforTreasureValleyairmasses10meterheight 50meterheight

GraphicscourtesyofIliasKavourasofTheDesertResearchInstituteandIdahoDepartmentofEnvironmentalQuality.

UsehighresolutionCOandNOxobservationstoevaluateemissions

•Parishetal.(2006)comparedmeasuredratiosofCOtoNOxtoemissionsinventories.

•MeasuredCOtoNOxratiosaremuchlowerthanemissionsinventories.

•WhatisthesituationinBoise?

TimeseriesofCOandNOxduringJanuary2009

0.6

0.5

0.4

0.3

0.2

Ben

zene

, Tol

uene

, C2-

Ben

zene

s, (

nmol

/mol

)

242220181614121086420Time of Day

45

40

35

30

25

20

15

NO

x, (nmol/m

ol)

300

280

260

240

220

200

180

160

CO

, (nm

ol/m

ol)

Diel CO Diel NOx Diel Benzene Diel Toluene

DiurnalconcentrationsofautomobileexhausttracersandNOx

250

500

750

1000

250 500 750 1000

0

45

90

135

180

225

270

315

CO, (nmol/mol) NOx, (nmol/mol)

•COandNOxlevelsdisplayedlittlewinddirectiondependence.•CO/NOxratioswerealsonotdependentonwinddirection

ObservedCOvs.NOxratiofortheentiremonitoringperiod(90sdata)

ObservedCOvs.NOxratioduringmorningrushhour(5:00amto9:00am)

DielvariationofΔCO/ΔNOxfromDec2,2008toJan31,2009

EmissionsgeneratedforAIRPACT‐3

•76%COemissionsmobile•57%NOxemissionsmobile

MeasurementandAIRPACT‐3resultsforJanuary2009

AIRPACT‐3TotalEmissions

AIRPACT‐3MobileEmissions

Measuredmixingratios

AIRPACT‐3mixingratios

HistogramofAIRPACT‐3andmeasuredCOmixingratios

HistogramofAIRPACT‐3andmeasuredNOxmixingratios

Source ΔCO/ΔNOxMeasurement (mol/mol)

Entirecampaignhighres. 4.6Rushhourhighres. 4.0Rushhourmedian 3.6

Entirecampaign1hravg. 4.6IDEQ1hr 3.3Model

Mixingratioresults 13.8Mobileemissions 18.9TotalEmissions 14.4

EmissionsRatioSummary:

2.5

2.0

1.5

1.0

0.5

Ben

zene

, (nm

ol/m

ol)

12001000800600400200CO, (nmol/mol)

SLOPE=0.0013 ± 0.00005

R2=.88

Morning Rush Hour Benzene vs. CO

BENZENE vs. CO fit_BENZENE vs. CO

5

4

3

2

1

0

Tol

uene

, (nm

ol/m

ol)

12001000800600400200 CO, (nmol/mol)

Rush Hour Toluene vs CO fit Rush Hour Toluene vs CO

Morning Rush Hour Toluene vs. CO

SLOPE=0.003 ± 0.0005

R2=.88

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

Ben

zene

, (nm

ol/m

ol)

20015010050 NOx, (nmol/mol)

Morning Rush Hour Benzene vs. NOx

Benzene vs. NOx fit_Benzene vs. NOx

SLOPE=0.0054 ± 0.0005

R2=.77

3.5

3.0

2.5

2.0

1.5

1.0

0.5

Tol

uene

, (nm

ol/m

ol)

20015010050 NOx, (nmol/mol)

Rush Hour Toluene vs NOx fit Rush Hour Toluene vs NOx

Morning Rush Hour Toluene vs. Nox

SLOPE =0.010 ±.001

R2=. 73

VOCRatiosformorningrushhour

Conclusions:•ModelCO/NOxratiosare3to4timeshigherthanobserved

•HistogramssuggestthattheemissionsinventorycapturesNOxemissionsbetterthanCOemissions.

•HowwillthischangewithanewEIand/orwiththenewMOtorVehicleEmissionsSimulator2010(MOVES2010)?

•Howdomodelratioscomparetoobservationsforotherspecies(VOC/NOx)?

Acknowledgements:WewouldliketothankIDEQforsupport,NSFforfundingtheMobileAtmosphericChemistryLabandNW‐AIRQUESTforsupportoftheAIRPACTforecastsystem.

Instrumentation:

NOx:•AirQualityDesign,Inc.twochannel,highsensitivity,chemiluminescentNOdetector.•Molybdenumoxidecatalyticconverteronchannel1(NOy).•SolidstatephotolyticNO2converteronchannel2(NOx).•Calibrationinzeroairwith5.03ppmv±1.0%EPANOstandardfromScottMarrin,Inc.•90secondaverage

CO:•AeroLaserAL5002FastCOMonitor.•Spancalibrationwith0.250%±2%NISTtraceable.•90secondaverage