ManagingAirQualityinaChangingWorld

DonaldJ.Wuebbles,SwarnaliSanyalandJunZhangDepartmentofAtmosphericSciences

UniversityofIllinoisatUrbana- Champaign

Date NameofMeeting 2

Thanks to EPA and the U.S. Clean Air ActThree times as much fossil fuel consumption now than in the 1960s, BUT pollutant emissions have been reduced by over 98%.

Net effect is that the air quality is much better now than it was then.

Warneke et al. (2012)

About200,000prematuredeathsintheUnitedStateseachyearfromoutdoorairpollution(MITstudy:Caiazzo etal.,Atmos.Environ.,2013)

Over3millionprematuredeathsworldwide;mostlyinAsia

FocusonO3 andPM2.5

Ø Ozone(O3)isamajorhealthriskasanirritanttorespiratorysystemandforreducinglungfunction² O3 isasecondarygaseouspollutantcreatedbyphotochemicalreaction

betweennitrogenoxides(NOx)andhydrocarbons(VOCs)

Ø ParticulateMatter<2.5μm indiameter(PM2.5)isamajorhealthriskthatcancauselungandheartissues² PrimaryPM- Agriculturaloperations,industrialprocesses,combustion

ofwoodandfossilfuels,constructionanddemolitionactivities,entrainmentofroaddustintoair,windblowndust,wildfires

² SecondaryPM– includesSOx,NOx,VOCsandNH4

Date NameofMeeting 5

HowclimatechangeaffectsairqualityØ Warmertemperaturesleads

tomoreO3 production.Ø Increasedwildfires increases

O3 andPM.Ø Driersoils,moreduststorms.Ø Effectsoflong-rangetransport

acrossnationalboundariesfromMexico,Canada,Asia,andNorthAfrica.

Ø Shiftsinweatherregimeslikejetstreams,Bermudahighs,stormactivitiesandhydrologicextremes.

Dust

Surface Ozone

Particulate Matter

Hg

Oil Spill

low jet

upper jet

LRT

Wildfire

Date NameofMeeting 6

ProjectObjectivesOur aim is:Ø To enhance understanding of how air quality in the United

States could evolve in future, with changing emission sources under a changing climate;

Ø To attribute key sources for major PM2.5 and O3 episodes on a local and regional basis; and

Ø To provide actionable information for designing effective air quality management strategies.

ProjectConceptualDesign

Focus on air quality over sensitive areas where high probabilities of PM2.5 and O3 exceeding the NAAQS have been issues in the past and are anticipated for the future subject to changes in climate, including climatic shifts in weather regimes (e.g. jet streams and Bermuda highs), storm activities, and hydrologic extremes.

Globalclimateandchemistry(CAM5-

chem)

Planetary

Forcing

RegionalclimateCWRF

NorthAmerica

AirQualityCMAQ

BaseEmissionSMOKEv3.5.1

IntercontinentalChemicaltransport

FutureEmission

EDGAR,GFED

U.S.PM2.5 &

O3

DynamicPredictionSystem

Date NameofMeeting 9

Ø ApplytheadvancedDynamicPredictionSystemtodetermineindividualandcombinedeffectsofglobalclimate& emissionschangesonU.S.airquality

Ø Quantifypollutionsourcesandassigntheirattribution– naturalvs.anthropogenicemissions,nationalvs.internationalagents,naturalvariationsvs.climatechanges

Ø Developatimelinefortheglobalchangefactorstobecomesignificanttotakeeffectiveactions

Approach

AnalysesusingBlueWaters

GlobalClimate-ChemistrysimulationsØ Historicalsimulations(1994– 2013)withmultipleensemblemembersat

both0.9ox1.25o AND0.25ox0.25o (CAM5-chem)Ø Futureprojections(2041– 2060)fortwofuturescenariosandensembles

U.S.RegionalClimateandAirQualitysimulations(CWRF/CMAQ)Ø CWRF– Historicalclimatestudiestodeterminebestrepresentationofmodel

physicsØ CWRF– HistoricalandFuturesimulationsforseriesofcasestudies(10km

resolution)Ø CMAQ– HistoricalandFuturesimulationsforeachcase(10kmresolution)

WhyBlueWaters?Ø Blue Waters enables high resolution simulations with the

global climate system modeling with fully coupled atmospheric chemistry.

Ø Blue Waters also enables a series of sensitivity and case studies with a state-of-the-science Dynamic Prediction system that couples Global models with Regional models over North AmericaØ To determine the individual and combined impacts of global climate

and emissions changes on U.S. air quality to 2050 under multiple scenarios.

RelativefactorscontributingtoO3(andPM2.5)

Based on He et al., 2016, Atmospheric Environment

Emission

Climate

LongRangeTransport

ModelDesign

RCP8.5(HighEmission)

RCP4.5(Intermediateemission)

2000 Lowscenario(2050– 2000)

Midscenario(2050– 2000) Highscenario(2050– 2000)

O3 surfaceconcentrationunderdifferentclimatescenarios

ØLowemissionsscenario(lowerconsumptionoffossilfuelandputsemphasisonglobalsolutionstoeconomic,socialandenvironmentalstability)

ØDecreaseoverNorthAmericaandEurope,andanincreaseovertheMideastandeasternAsia

Leieta.,2012

2000 Lowscenario(2050– 2000)

Midscenario(2050– 2000) Highscenario(2050– 2000) Leieta.,2012

ØHighemissionsscenarioemphasizesthecontinuedintensiveuseoffossilfuels

ØDerivesanincreaseofsurfaceO3concentrationupto40 ppboverlandareasthroughoutmuchoftheworld

O3 surfaceconcentrationunderdifferentclimatescenarios

Date NameofMeeting 15

ImpactsonUnitedStatesfromCanadianWildfires

ØEven a single wildfire event can put a region out of compliance with O3 or PM2.5standards

ØNeed to quantify O3 or PM2.5impacts from wildfires

ØThis requires models accounting for past and potential wildfires

Dreesen et al. (2016)

MODISTerraAODMaximum8-HourOzone 24-HourAveragePM2.5

Date NameofMeeting 16

Ø ExportofairpollutioncontributionfromChinasignificantlyaffectsairqualityintheUnitedStatesØ O3 export– rangesfrom

5.4%to6.9%Ø BlackCarbonaerosol

export– rangesfromabout0%ineasternUnitedStatesto22.7%inwesternUnitedStates

Linetal,2013,ProceedingsoftheNationalAcademyofSciences

ImpactsofLRTonNorthAmericanairpollution

Date NameofMeeting 17

Ø TheimportofaerosolstoNorthAmericais64Tg/year,includingtrans-Pacificdustandpollutionaerosolsandtrans-Atlanticdust.

Ø Theannualemissionsandproductionsofaerosolsof69Tg/yearfrommajordomesticsourcesinNorthAmericaisonlyslightlylarger.PrimaryPMemissionsincludeonlyanthropogenicsources(excludeswildfires).

Satellite-basedestimateofdustmassfluxinEastAsiaoutflowandNorthAmericainflow. Yuetal.,2012,Science

ImpactsofLRTonNorthAmericanairpollution

U.S.EPA:AirQualityEpisodes

Ø EPA’sNationalAmbientAirQualityStandards(NAAQs)Ø O3 daily8-hrmaximum70ppbvØ PM2.5 dailyaverage35µg/m3

annualaverage 12µg/m3 (primary)15µg/m3 (secondary)

Ø EpisodesmaybedefinedbythenumberofmonitoringsitesthatviolatethedailyNAAQSintheUnitedStates

TheAirQualitySystem(AQS)datacollectionsitesforOzone(1990– 2015)andPM2.5(2000–2015)

%oftime,thesitesviolatesNAAQS

2005

Welookat2005globallyandintheU.S.throughourmodelsimulationstoinvestigatethepollutantconcentrationsandNAAQsviolation(intheU.S.)

High Canadian/Mexican emissions along the U.S. northern/southern border can contribute to PM2.5and O3 violations in New England and California.

CWRF-CMAQPreliminaryStudy

O3 concentration PM2.5concentration

GlobalClimate-ChemistryPreliminaryStudy

Summary

Ø Global and regional model simulations underway are to be used to evaluate the factors affecting past and projected high pollution events in the United States for O3 and PM2.5

Ø Our Dynamic Prediction system is to be used to enhance scientific understanding of the impacts from global climate and emission changes and effects of long range transport on U.S. air quality management.

Ø Sensitivity and case study analyses using the Dynamic Predictionsystem are to be used to evaluate potential effects of various pollution sources on future air quality in the United States.

ThankYou