Reduction in Tropospheric NOx and Ozone Corresponding to ...

This map, created using measurements of atmospheric gases from NASA and European Space Agency Earth-observing satellites, shows how lower ... SearchAllStories... Search Earth  ID:4959 ReductioninTroposphericNOxandOzoneCorrespondingtoWorldwideCOVID-19Lockdowns Visualizationsby TrentL.Schindler ReleasedonDecember13,2021 WhentheworldwentintolockdowntoslowthespreadofCOVID-19,airpollutionemissionsstartedtorapidlydecreaseleavingaglobalatmosphericfingerprintdetectedbyateamofscientistsatNASA’sJetPropulsionLaboratoryusingsatellitemeasurements.Thesetracesprovidedanunexpectedwindowintowhatlow-emissionsworldcouldlooklike,thusprovidingameansforidentifyingeffectiveenvironmentalpolicies. Whilemanycountriesinthelastfewdecadeshaveimplementedenvironmentalpoliciestoreducehumanhealthriskfromairpollutionbycontrollingemissions,theimpactsofthosepolicieshavenotalwaysbeenclear.ThegloballockdownsinresponsetoCOVID-19representawell-observed“scenario-of-opportunity”thatallowsustoassesshowatmosphericemissionandcompositionrespondstoreducedhumanactivity. COVID-19lockdownseffectivelyshowedhowreducingNOxemissionsaffectstheglobalatmosphere.Itsidentifyingsignatureshowsupasintheatmosphere’salteredabilitytoproduceharmfulozonepollutionandozone’sreducedinfluenceonEarth’sheatbalancethataffectsclimate.Theseeffectsarenotuniformacrosstheworldanddependonthelocationandseasonoftheemissionreductions. Theresultsofthisresearchindicatethatinordertodesigneffectiveenvironmentalpolicieswhichbenefitbothairqualityandclimate,decision-makersneedtocarefullyconsiderthecomplexrelationshipsbetweenemissionsandatmosphericcomposition. DownloadOptions 5760x324030.0fpsFrames:Nox_hyperwall 1024x576jpeg(122.0KB)StillImage 3840x2160mpeg-4(13.6MB)30.0fps 1920x1080mpeg-4(11.9MB)30.0fps Rightclickmoviestodownloadthemiftheyautomaticallyplayinyourbrowser. Theteamfocusedondroppinglevelsofnitrogenoxides,orNOx,whichareemittedlargelyfrompowerplantsandcarexhaust.Italsoreactstoformsurface-levelozone–aninvisiblecontributortosmogandaharmfulpollutanttohumanhealth. Atthecountryscale,theevolutionofNOxemissionreductionsovertimeisstronglycorrelatedwiththeCOVID-19GovernmentResponseStringencyIndex,anindicatoroftheseverityofgovernmentlockdownmeasurestoslowtransmissionofCOVID-19. ChineseNOxemissionsrapidlydeclinedfromlateJanuarythroughlateFebruary,correspondingtoChina’sfirstlockdown.ThiswasfollowedbyarapidrecoverytotheirnormallevelsforMarchandApril.InMay,theemissionsagainstartedtodecreasecorrespondingtoasecondlockdowninsomepartsofthecountry. InItaly,theearlyimplementationoflockdownledtolargeemissionreductionsbeforeotherEuropeancountries,fromlateFebruarytoearlyMay. MostofthestatesintheUnitedStatesannouncedemergencystay-at-homeordersinlateMarch.TheestimatedemissionsshowdeclinesbeginninginlateFebruaryandearlyMarch,withmaximumreductionsofabout25%inAprilandMay,followedbyamoderaterecoveryinJune. Theteamfoundthat,globally,emissionsofNOxdecreased15%. DownloadOptions 5760x324030.0fpsFrames:O3_2d 1024x576jpeg(153.0KB)StillImage 3840x2160mpeg-4(69.0MB)30.0fps 1920x1080mpeg-4(48.0MB)30.0fps Rightclickmoviestodownloadthemiftheyautomaticallyplayinyourbrowser. Ozonereductionscorrespondingtoemissiondecreasesfromlockdownsineachregionoftheworldshowdistinctpatterns,bothlocallywherethelockdownsoccurredandremotelyduetotheglobalcirculationoftheatmosphere.Theresultsdemonstratethatwhereandwhenthelockdownsoccurredisveryimportantindeterminingtheimpactonatmosphericcomposition. Toidentifyregionalandseasonalchangesintheozoneresponse,theteamconductedmodelsimulationsforeachregionseparately.Foreachmodelsimulationshownhere,onlytheNOxreductionsforthatregionwereused,leavingtherestoftheglobeatthestatusquo.Thisallowedtheinvestigatorstoavoidseeingoverlappingeffectsfrommorethanoneregionatonce. Eachregionshowsdistinctpatterns: OzoneproductionfromNOxismostefficientinthetropicsbecauseofwarmerandsunnierclimate. TheSouthAmericanemissionreductionsresultinalongtailofdecreasedozonealongthemid-latitudewesterliesintheSouthernHemisphere. TheEuropeanandAustralianemissioninfluencesonozonearemostlylimitedtotheregionpolewardof30°,linkedtothemovementsoflargeairmasses,likecoldorwarmfronts,thatscalethousandsofmiles. Overall,thelockdownsinthenorthernmidlatitudeshadthelargestimpactonozoneconcentrationsbecausereductionsinNOxemissionswerelargestthere. DownloadOptions 5760x324030.0fpsFrames:O3_2d_5ppb 1024x576jpeg(134.0KB)StillImage 3840x2160mpeg-4(46.8MB)30.0fps 1920x1080mpeg-4(33.4MB)30.0fps Rightclickmoviestodownloadthemiftheyautomaticallyplayinyourbrowser. Thisisanalternateversionofthepreviousvisualization,usingadatarangeof5ppbratherthan2ppb. DownloadOptions 5760x324030.0fpsFrames:O3_world_volume 1024x576jpeg(244.0KB)StillImage 3840x2160mpeg-4(247.5MB)30.0fps 1920x1080mpeg-4(180.7MB)30.0fps Rightclickmoviestodownloadthemiftheyautomaticallyplayinyourbrowser. Theteamlookedatthelockdowns’impactsonglobalozonepollutioninthetroposphere—thelowestlayeroftheatmosphere,fromthesurfacetoabout40,000feet(roughlywerepassengerjetsfly).Asopposedtotheprotectiveozonelayerinthestratosphere(thelayerabovethetroposphere),thetroposphereozoneisanimportantgreenhousegas. Thismap,createdusingmeasurementsofatmosphericgasesfromNASAandEuropeanSpaceAgencyEarth-observingsatellites,showshowloweratmosphericozonereductionsoccurredworldwide. NASAsatellitesshowedthatthedropinNOxresultedina2%globaldropofozone.Whilethismayseemsmall,thisdropinozone,whichoccurredover8months,wouldtake15yearstoachieveunderevenaggressiveemissioncontrolscenarios. OzonedependsonanumberoffactorsandnotjustNOxemissionsalone,whichiswhytheteampulledtogetheravarietyofairqualitymeasurementsandcombinedthemwithamodeltounderstandwhathappened. DownloadOptions 5760x324030.0fpsFrames:O3_regions_volume 1024x576jpeg(154.0KB)StillImage 3840x2160mpeg-4(151.8MB)30.0fps 1920x1080mpeg-4(107.8MB)30.0fps Rightclickmoviestodownloadthemiftheyautomaticallyplayinyourbrowser. Asianemissionsshowadistinctpattern,withlargeozonereductionsintheuppertropospherearound40,000feetextendingthroughoutthetropicsandtothemidlatitudesofbothhemispheres. Thispatternreflectshowinthetropicswarmairrisestohigheraltitudesandspreadsnorthandsouthward,andalsohowitistransportedbytheAsianmonsoon.TheresultssuggesthumanactivityinAsiahasasubstantialimpactontheglobalenvironment. Meanwhile,reducedlockdownemissionsinNorthAmericareducedozoneuptoabout40,000feetfromthegroundfarthernorthward,widelyoverthenorthernmidandhighlatitudesintoCanada,EuropeandtheArctic. ThemovementofthesignalofreducedozonelevelsfromAsianandNorthAmericanemissionsalsohasimplicationsforozone’sheat-trappingabilityasagreenhousegas.Ozonehasthe3rdlargestimpactontheradiativebalanceoftheatmosphere. VisualizationCredits TrentL.Schindler(USRA):LeadVisualizer KazuyukiMiyazaki(JPL):LeadWriter EllenT.Gray(ADNET):Writer EllenT.Gray(ADNET):LeadProducer KatieJepson(KBRwyle):Producer KevinBowman(JPL):LeadScientist KazuyukiMiyazaki(JPL):Scientist Pleasegivecreditforthisitemto:NASA'sScientificVisualizationStudio ShortURLtosharethispage: https://svs.gsfc.nasa.gov/4959 Keywords: DLESE>>Atmosphericscience DLESE>>Environmentalscience GCMD>>EarthScience>>Atmosphere>>AirQuality GCMD>>EarthScience>>Atmosphere>>AirQuality>>NitrogenOxides GCMD>>EarthScience>>Atmosphere>>AtmosphericChemistry/OxygenCompounds>>Ozone SVS>>Hyperwall NASAScience>>Earth GCMD>>EarthScience>>Atmosphere>>AtmosphericChemistry>>NitrogenCompounds SVS>>COVID-19 SVS>>COVID19 GCMDkeywordscanbefoundontheInternetwiththefollowingcitation: Olsen,L.M.,G.Major,K.Shein,J.Scialdone,S.Ritz,T.Stevens,M.Morahan,A.Aleman,R.Vogel,S.Leicester,H.Weir,M.Meaux,S.Grebas,C.Solomon,M.Holland,T.Northcutt,R.A.Restrepo,R.Bilodeau,2013.NASA/GlobalChangeMasterDirectory(GCMD)EarthScienceKeywords.Version8.0.0.0.0 SearchAllStories... 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