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Thereisgoodozoneinthestratosphereandbadozoneinthetroposphere

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Showstheloca8onandimplica8onsofgoodandbadozone.GoodozoneisintheStratosphere;itabsorbshighenergyuvlightandprotectslifefromitseffects,likemuta8ons.Badozoneisinthetroposphere,affec8ngtheairwebreathe,humanandplanthealth

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Highenergy,andveryshortwaveultravioletlightsplitsO2moleculesandthesingleOmoleculescancombinewithotherO2moleculesandformozone,O3Theproduc8onofozoneisnotuncheckedduetoitsdestruc8onbyCFCsandnitrogencompounds,whichareleadingtotheozoneholeovertheAntarcr8c

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UvlightbreaksupCFCs,releasingachlorineatom,Cl.ThiscleavesO3,ozone,toformClO.OtherOmoleculessplitClOtoenablefreeClatomstorepeatthesetofreac8ons.Todayversionsofhydrofluorocarbons(HFCs)arereplacingCFC,chlorofluorocarbons,hydrochlorofluorocarbons,HCFC,

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hRps://www.nsf.gov/about/history/nsf0050/arc8c/ozone.htm

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hRp://www.psi.ch/lac/ProjectDetailOzoneTrendsEN/igp_1024x640%3E_o3_trends_long.jpgOzoneisnotwellmixedlikeotherlonglivedgreenhousegases.Whilethereareregionaldifferencesinabsoluteozone,ingeneralthereisaworldwideincreaseinitsconcentra8on.Earliestdataareattheturnofthe20thCenturyinParis,whereconcentra8onswerebelow20ppm.Thedensityofmonitoringnetworkshaveimproved,assotheinstruments,sothemodernrecordisviewedasmorereliable.

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Observedtrendsinozone

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Thefreshsmellinthewoodsarevola8leorganichydrocarbons,likemonoterpenesandisoprene.Theyplaypivotalrolesintheproduc8onofphotochemcialozone

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Simplesetofreac8onsthatleadtothephotochemicalproduc8onofozone

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Whetherozoneisproduceddependsonthecombina8onofVOXandNoxconcentra8ons

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VOCsplaymanyrolesinregardstoproducingaerosolsthatcanreflectlightoractascloudcondensa8onnucleii.Chemically,theyplayacentralroleinozoneproduc8onandforbiologytheyhelpplantsdefendagainstpathogensandaRractpollenators.

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hRp://www.nature.com/nature/journal/v525/n7568/images_ar8cle/nature14986-f1.jpg

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Wewillcovernitrogengaseslaterinthiscourse.Thisisjustaquickintroduc8onofthebiogenicgasesthatareimportant

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OzoneinthestratosphereisdepletedfromClfromCFCandNOfromN2O.SingleOatomscauseN2Otoform2NOmoleculesandtheNOleadstothedestruc8onofO3.N2O+O(1D)->2NONO+O3->NO2+O2NO2+O->NO+O2Net:O+O3->2O2

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Tg=10^12g

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HerearesomeKeypoints..Helpiden8fyothersgleanedfromthislecture.

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MapshowingtheAntarc8cozoneholein2003SusanSolomon,aUCBgraduate,wasinstrumentalindiscoveringthemechanismforozonedestruc8onintheStatosphere.SheconductedmanystudiesinAntarc8ca.Earlydetec8onwasmissedbyNASAastheythoughttheholewasanoutlierintheperformanceoftheirinstruments.

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AnoverviewoftheozoneholeisproducedbyNASAhRp://aura.gsfc.nasa.gov/ozoneholeposter/Ozone-Hole-Poster_hiRes_508.pdf

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