ZitelyTzompa-Sosa,B.Henderson,K.Travis,E.V.Fischer

Evalua8ngupdatedlightalkaneemissionsfromtheoilandnaturalgasindustryintheU.S.

Photocredit:www.beforethelastdrop.com

•  AlkaneemissionsintheNEI2011ek(newestversion)arelargeroveroilandnaturalgasbasins.•  Simula8onsofC2H6andC3H8underes8mateobserva8onsovertheCentralandSouthEasternU.S.•  Theupdatedinventorywillbeusedtoassessimpactsonsecondaryspecies.

*SpecialthankstoAlanFried,DirkRichter,Pe>erWeibring,JamesWalega,&DonaldBlakeforprovidingobservaGonaldataforthiswork,andChristophA.KellerforhelpwithHEMCO.

September14th,2017

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East South Central Central

South East North Central West

Midwest NG Annual Gross Withdrawals

ManyregionsoftheU.S.haveseenanincreaseinoilandnaturalgasdevelopmentsince2000.

Francoetal.,2016

•  Emissionratesareuncertain(nextslide)andrapidlychanging.

•  Thesefactorspresentachallengeforemissioninventories.

Totalemissionsfromthissector,andtheircomposi8on,dependonmanyfactors.

Spa8aldistribu8onofaveragedpercentagemolarC2H6/CH4ra8osinoilandnaturalgasbasinsoverthecon8guousU.S.

Emissionleakagedependson:•  typeofoilandnaturalgasreservoir(e.g.,8ghtgasvsshalegas)•  VOCcomposi8onofthenaturalgas•  produc8onstageofthewell•  Technologyandapplica8onofinsituemissioncontrols

Warnekeetal.,2014

Tzompa-Sosaetal.,2017

ThelatestversionoftheNEI(2011v6.3)includesupdatesoveroilandgasbasins;weincorporateditintoGEOS-Chem.

Hereisanexamplemapoftheseemissionsata0.5°x0.6°resolu8on.

C2H6anthropogenicemissions(ngm-2s-1)

NEI2011v1edBEFORE

NEI2011v6.3ekAFTER

Theupdatedimplementa8on(NEI2011v6.3ekvs.v1ed)increasesalkaneemissionsoilandgasproducingregions.

ALK4

NEI2011v6.3ek–NEI2011v1edemissionfluxesat0.5°x0.6°resolu8on(ngm-2s-1)

Rela8veemissionincreasesofC3H8andalkanes>C4arelargerthanC2H6intheupdatedinventory.

x 100(NEI 2011v6.3ek – NEI 2011v1ed) NEI 2011v1ed

AnestedGEOS-Chemsimula8on(for2011)wascomparedtomul8pleobserva8onaldatasets.

Anestedsimula8on(0.5°x0.6°)underes8matesC3H8abundancesovertheCentralandSouthEasternU.S.

•  Underes8matesoverthesameregionsoccurforC2H6.

00.020.040.10.30.5246C3H8ppbv

•  InGEOS-Chem,>C4alkanesarealumpedspeciescalledALK4.

•  WhencomparedtothesumofC4andC5alkaneobserva8ons,themodelabundancesarehigher.

00.030.10.531050400ALK4&>C4

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