PM25监测设计模型解读课件

1Designationsforthe2006PM2.5Standards:EvaluatingtheNineFactorsinSettingNonattainmentAreaBoundaries

1Designationsforthe2006PM22

The9DesignationFactors

ToHelpDetermine

NearbyAreaofInfluence

for24-hrNAAQSViolationsEmissionsAirQualityMeteorologyTopographyPoliticalandOtherBoundariesCurrentEmissionControlsGrowthTraffic&CommutingPopulationandUrbanizationNonAttainmentBoundariesAirQualityisoneofthemostImportantDesignationFactors2The9DesignationFactors

T3TopicstobeCoveredConceptualmodelforhighPMdaysSeasonswhenexceedancesoccurCompositionofthehighdaysAnalyticaltoolsSLICEtechnique-forevaluatingurbancontributionstohighdaysResidencetimeanalysis–forassessingnearbycontributingsourceregionsusingbacktrajectoriesandemissionsdataGradientanalysis–foridentifyingdayswithpotentialhighsource-orientedimpacts3TopicstobeCoveredConceptua4ConceptualModelforHighPM2.5DaysHowtodefinehighPM2.5days?Whatisthetypical“dailyincrement”forhighPMdaysinrelationtotheannualaverage?Whatistheurbancontributionaboveregionallevels?4ConceptualModelforHighPM25ConceptualModelforHighPM2.5Days

WhathighPM2.5daystoconsider?“HighPM2.5Days”Associatedwiththe98thpercentileNotjustonedayperyearSelectallcandidatedays e.g.top5%ordays>30-35ug/m3Summarizebyseasontodistinguishvaryingconditions5ConceptualModelforHighPM2640ug/m31624PM2.5HighDayValueSeasonalAverage+TypicalDailyIncrementExampleTypicalDailyIncrement-ExampleTheannualaveragePM2.5(urbanbackground)isthestuffthatisthereonaday-to-daybasis.ComesfromnearbyandmoredistantareasCanbeestimatedbyseasonalaveragePM2.5concentrationofnon-highdaysIncludescontributionsfromallnearbysurroundingcountiesCanbeestimatedusingthetraditionalurbanincrementapproachThedailyincrement(ontopofannualaverageurbanbackground)alsohasregionalandlocalcontributions.-Keyissue:whatcountiesandsourcesfromtheurbanareacontributetothetypicaldailyincrement?ConceptualModelforHighPM2.5Days

HighDailyPM2.5hasUrbanandRegionalComponents640ug/m31624PM2.5Seasonal+Typ7ConceptualModelforHighPM2.5Days

Anapproachtopartitiontypicallevelsinto

urbanandregionalcomponentsUrbanIncrementAnalysesasusedin2004/2005PM2.5DesignationsUrbansourcesintheEasternUScontributeatleast4-6ug/m3toannualaveragePM2.5

ProbablyevenlargerurbancontributioninwesternUScitiesCarbonissignificantcomponentofaveragePM2.5mass,butmetroareaemissionstypicallyaremuchlessthanSO2andNOxWeightedemissionsscoredevelopedtogiveadditionalweighttonearbydirectcarbonemissionsastheycontributetotheurbanbackground7ConceptualModelforHighPM28urbanincrementPM[µg/m³]naturalbackgroundUrbanareas~14-20ug/m3Countryside~10-12ug/m310152030253540ConceptualDiagram-AnnualAveragePM2.5

AirQuality-AnnualAveragePM2.5

regionalcontributionWesternUSurbanareasmayhavesmallerregionalcontribution8urbanincrementPM[µg/m³]natu9urbanincrementPM[µg/m³]naturalbackground10152030253540ConceptualDiagram-HighDailyPM2.5Concentrations

AirQuality-HighDailyPM2.5ConcentrationsregionalcontributionUrbanareas~30-40ug/m3Countryside~18-30ug/m3Larger“urbanisland”onpeakdaysFocusofnewanalyses:understandingwhatemissionscontributetourbanincrementWesternUSurbanareasmayhavesmallerregionalcontribution9urbanincrementPM[µg/m³]natu10ConceptualModelforHighPM2.5Days

SourceregionconsiderationsRoleofRegionalvsUrbanvsMicro-scaleInfluencesOnhighdaysparticularlyintheeast,regionalemissionsoftenprovidea“base”amountofpollutionUrban-wideandnearbyemissionsalsocontributesignificantlytohighdays:“urbanisland”effectInsomecases,theremaybeamicro-scaleeffectfromasinglesourceorsmallgroupofsourcesDoesnothelpdefineNAboundaries,unlessitistheonlycontributingsource(Note:“urban”canmeanlargemetropolitanareaorsmallercity)AirQuality10ConceptualModelforHighPM11ConceptualModelforHighPM2.5Days

SeasonswhenexceedancesoccurTimeofYearforExceedances-variesbyGeographicRegionSE:MostlysummerIndustrialMidwest(IMW),Mid-Atlantic,So.CA:WinterandsummerNW,UT,NM,MiddleCA:MostlyorexclusivelyWinter11ConceptualModelforHighPM12%50

250NWUTIMWMidCAS.CASEMidAtlPercentof2003-05FRMDays>35ug/m3byMonthBasedonallsiteswhichviolate24-hrNAAQSJFMAMJJASONDJFMAMJJASONDJFMAMJJASONDLaCruces,NM%50

250JFMAMJJASOND12%50NWUTIMWMidCAS.CASEMidAt13ConceptualModelforHighPM2.5Days

CompositiondataareimportantCompositionIndicatewhichsourcesarecontributingtoaverageandhighPM2.5valuesVariesacrosscountryWarmseasonexceedances:

Mostlysulfate+organiccarbonColdseasonexceedances:

Nitrate(athigherlatitudesandinWesternUS)+sulfate+carbon;Carbonmaydominateinsomelocations(e.g.MT,ID)GapsinspeciationdataforcertainareasAirQuality13ConceptualModelforHighPM14CompositiononAnnualAverageandHighPM2.5Days(FromPMStaffPaper)

SomesourcecategoriesandregionalinfluencesmaybemoreimportantforhighconcentrationdaysComparingaverageof5highestdaysduring2003,regionalsourcesofsulfatesandnitratesarelargercontributorstopeakdayconcentrationsthantoannualaverage(selectedcityanalysis)CompositioncanvaryfromhighdaytohighdayCarboncanbesmalleras%--butstilllargerinabsoluteconcentrationvalues--comparedtotheaverageNote:Allthenewanalysespresent“FRM”compositionwiththepeer-reviewed“SANDWICH”TechniqueAsusedinCAIRandPM2.5RIASMWCANEFromPMStaffPaper(Raoetal)BirmAtlantaNYCClevelandChicagoSt.LouisSLCFresnoUTMoreSulfateMoreNitrateHighPM2.5dayshave:NitrateTCMSulfateCrustal

ThisanalysisshowsPM2.5Compositionoftheambientaerosol(notadjustedtorepresentFRMmass)AirQuality14CompositiononAnnualAvera15NWUTIMWMidCAS.CALaCrucesNMSEMidAtlAvgHigh3ColdAvgHigh3WarmAvgHigh3ColdAvgHigh3WarmAvgHigh3ColdAvgHigh3WarmAvgHigh3Cold“Example”CompositionforHighDays[“Warm”Season(May-Sept)&

“Cold”]Butsitescanbedifferentwithineach“domain”ColdColdWarmColdWarmWarmColdWarmColdColdColdElPasoSTNorJFMAMJJASONDJFMAMJJASOND%50

250%50

250Piesrepresentaverageof3highestdaysperyearperseason,usingSANDWICHor15NWUTIMWMidCAS.CALaCrucesSE16Compositionisoftensimilaramongthehighdays3highestPM2.5days>30ug/m3Perseason,Milwaukee,WI(2003-05)AverageCoolSeasonWarmSeasonMeasuredPM2.5mass,ug/m3BlacklineisdifferencebetweenOCMmbandOCM14Milwaukee,2003-05PM2.5days>30ug/m316Compositionisoftensimilar17UseresidenttimeweightedemissionstopartitioneachcomponentoftotaldailyIncrementsintourban®ionalcontributions(%ofRTWEinlocalarea)ConceptualModelforHighPM2.5Days

AnapproachtopartitiontotaldailyincrementintourbanandregionalcomponentsDailycompositionminusSeasonalavg.PM2.5days>30ug/m3Perseason&year,Milwaukee,WI(2003-05)MeasuredPM2.5massTheurbanbackgroundPM2.5canbeestimatedusingseasonalaveragePM2.5concentrationofnon-highdaysCoolWarmCoolseasonWarmseasonNextsubtractthedailycompositionfromtheseasonalaveragePM2.517Useresidenttimeweightede18AnalyticalTools

tohelpidentifyboundariesanddevelopSIPsSLICEtechnique-forevaluatingurbancontributionstohighdaysResidencetimeanalysis–forassessingnearbycontributingsourceregionsusingbacktrajectoriesandemissionsdataUrbangradientanalysis–foridentifyingwhetherthereareanysitespredominantlyaffectedbyasinglesource18AnalyticalTools

tohelpide19“SLICE”toidentify“urbanisland”daysandrelativeurbanamountofPM2.5massEvidenceofurbansourcecontributionsUrban“gradient”techniqueEvidenceofpredominantstrongnearbysourceinfluenceAnalyticalTools

IdentifyurbanPM2.5andgradientsAirQualityAirQualityEmissionsMetDailyurbanportionofPM2.519“SLICE”toidentify“urbani20AnalyticalTools-ResidenceTimeAnalysis

Wheredidtheairparcelcomefrom

onhighconcentrationdays?TransportpatternsproducingapotentialsourceregionUsetrajectoriesand“Residence-TimeAnalysis”tofindupwindprobabilityfields.ForPM2.5massoritscomponentsFocusontheensembleof“HighPM2.5days”,byseasonforsubsequentlinkingtocompositionpattern.Dayswithidentified“urbanislands”aremoreimportantLocalpollutionroses(annualvs.highdays)wouldalsobehelpfultoidentifynearbysources.MetAirQualityResidencetimeprobabilityplotswithHYSPLITtrajectorieshavebeenusedbyKinski,Poirotandotherstoidentifypotentialsourceregions.20AnalyticalTools-Residence21AnalyticalTools-Residencetimeweightedemissions

Whatare

themostlikelycontributingemissions?Spatialdistributionofemissionsbyseason

DevelopedfrommonthlyemissionsforprecursorsanddirectPM:(SO2,NOx,Carbon,Crustal)TheimportanceofeachprecursorpollutantcanbeguidedbythecompositionofthehighPM2.5day.considermonthlyemissionscorrespondingtotheaffectedPMcomponentaccordingtotypicalcompositionbyseason.Someprecursorswillnotbeconsideredorcouldbedown-weighted.e.g.crustal(year-round)andNOX(summer).Res