Report:Technical

COPrimaryNOAAofAnalysesInfrared 22-in-Air

1991-1999SIO,atStandardsGasReference

by

MossD.Keeling,D.C.Bollenbacher,A.Guenther,R.P.

OceanographyofInstitutionScripps

DiegoSanCalifornia,ofUniversity

92093CAJolla,La

2002March,

ContentsofTable

1....................................................................................................................Introduction1.

2..........................................................................SystemAnalysisInfraredSIO/CDRG2.

GasesReferencePrimaryNOAA/CMDLofMeasurementsAnalyzerAPC3.

4.........................................................................................................................1999in

COofAssignment4. 2 7..................................................................AirinFractionsMole

CONOAA/CMDLandSIO/CDRGofSummary5. 2 9.........1991-1999Fractions,Mole

11............................ScalesCalibrationNOAA/CMDLandSIO/CDRGofComparison6.

16..........................................................................................................................References

CONOAA/CMDLof1999inmeasurementsinfraredSIO/CDRG1.Table 2-in-air

17....................................................................................standardsgasreferenceprimary

infraredSIO/CDRGandmanometricNOAA/CMDLofComparison2.Table

standards,gasreferenceprimaryNOAA/CMDLof1991-1999,fromanalyses,

18.........................................................................scalesX99NAandX99Ainexpressed

infraredSIO/CDRGandmanometricNOAA/CMDLofComparison3.Table

standards,gasreferenceprimaryNOAA/CMDLof1991-1999,fromanalyses,

19.........................................................................scalesX99NBandX99Binexpressed

Introduction1.

DioxideCarbonthebetweenintercalibrationdecade-longaonreportweHere

Cli-theand(SIO)OceanographyofInstitutionScrippstheat(CDRG)GroupResearch

andOceanicNationaltheof(CMDL)LaboratoryDiagnosticsandMonitoringmate

desig-thebeenhasNOAA/CMDL1995Since(NOAA).AdministrationAtmospheric

COCentralnated 2 Organi-MeteorologicalWorldtheof(CCL)LaboratoryCalibration

standards,gasreferenceprimarynatural-air15ofsetASIO/CDRG.replacingzation,

COoffractionmoleinranging 2 bycreated(ppm)millionperparts521to246from

meas-ofcalibrationtheforstandardinternationalthecomprisesnowNOAA/CMDL,

COatmosphericofurements 2 manometricallycalibratedbeenhavestandardsThese.

al.,et[ZhaodesigntheirofmanometervolumeconstantausingNOAA/CMDLby

1997].

non-awithanalysedandSIO/CDRGtosentwasstandardsofsetthis1999,In

ofsystemcalibrationthecloselycomparetoanalyzergas(NDIR)infrareddispersive

1995.topriorCCLdesignatedthewaswhichSIO/CDRG,ofthattoNOAA/CMDL

8timethisAlso,1991.inoccurringfirstthefourth,thewasintercomparisonThis

constanttheonmanometricallymeasuredweresetNOAA/CMDLtheofstandards

toreportedasSIO/CDRG,of(CMM)manometermercury-columnvolume

measure-additionalreportweHere[2000].KeelingandGuentherbyNOAA/CMDL

Cor-PhysicsAppliedtheon1999inmadestandards,gasreference15allofments

analyzerAPCthereviewweAlsoSIO/CDRG.ofanalyzerNDIR(APC)poration

SIO/CDRGtheandSIO/CDRG,atcalibrationspreviousthreetheformeasurements

gases.theseof8ofanalysesmanometric

-2-

SystemAnalysisInfraredSIO/CDRG2.

COThe 2 COtheinterrelatesSIO/CDRGatsystemcalibrationgasreference 2 con-

toproportionalisthatscale(I)"index"anofmeansbygasesreferenceofcentrations

chartaontracesbetweendistanceaasexpressedanalyzer,APCtheofresponsethe

vol-outputinstrumentfromdirectlydeterminedequivalentdigitalaorrecord,paper

fractionmoleinmillionperpartstocloseunitsinexpressedareI-indicesThetages.

designation.correctapproximatelyanonlyisthisalthough"ppm",inlabeledand

units,ppmI-indexindifferencesasexpressedaregasesreferenceofIntercomparisons

"REFGAS".calleddata-baseandprogramausingtabulatedandcalculatedroutinely

standards.gasreferencesecondaryandprimarybothofsetsmaintainsSIO/CDRG

COThe 2 determinedset,primarytheofairdrytorespectwithfractionsmole

COofconcentrationstruerepresentCMM,thewithmanometrically 2 COThe-in-air. 2

pri-thewithintercomparisonsbyestablishedaresetsecondarytheoffractionsmole

units.I-indexinexpressedinitiallyresultsanalyzer,APCtheusingstandardsmary

instrument’stheofdivisionscaleperunitsI-indexinsensitivity,instrumentThe

gassecondarytwoofresponsesfromdaycalibrationeachondeterminedisrecorder,

approxi-arestandardstwoThesestandard.span""highaand"principal"astandards:

offractionmolecurrentthenearcenteredfraction,moleinapartppm20mately

COatmospheric 2 (RSF)factor"scale"recorderatabulatesandcalculatesREFGAS.

measuredthecomparesdirectlyandsensitivityinstrumentthetoinversetheiswhich

betweendifferencescalethetostandardssecondarytwothebetweendifferencescale

theofcreationtheatI-indexinapartppm18betodefinedstandards,originaltwo

follows:asdefinedthusisRSFThe1957.insystemstandardgassecondary

-3-

RSF =IDSD × (1)18

SDwhere = highandprincipalthebetweendifferencescalemeasured

standardssecondaryspan

ID = highandprincipalthebetweendifferenceI-indexassigned

standardssecondaryspan

rangetheinconcentrationtruetocloserscale,index""adjustedanSubsequently

stan-primaryofmeasurementsmanometricfromestablishedwasppm,340to310of

thetoproportionalalsoisJ-index,thecalledscale,ThisCMM.thewithdards

followsasdefinedanalyzer,APCtheofresponse

J = 1.2186 × (I−311.51) + (2)311.51

Jwhere = ppm)(inJ-index

I = ppm)(inI-index

beenhasanalyzerAPCtheofresponsenonlinearthepresent,theto1974From

COofrangetheoverdetermined 2 respectwithppm,500to200fromfractions,mole

isresponseTheppm.10aboutofconcentrationvaporwateratodriedair,naturalto

aovergasesreferenceprimarySIO/CDRGofsetthemeasuringbydetermined

relationshipTheapart.weekaaboutspacedtypicallyfive,usuallydays,ofsequence

COdeterminedmanometricallytheandJ-indexthebetween 2 asuchforfractionmole

equa-calibrationpolynomialcubicabyexpressedthenisperiodcalibrationspecific

Foryears.twoeveryapproximatelyrepeatedbeenhaveperiodscalibrationSuchtion.

ofdatecentraltheforvalidbetodeemedscale,calibrationadesignateweperiodeach

rela-thedefineperiodeachforequationscalibrationCubiccalibrations.ofsequencea

COtoJ-indexoftionship 2 calibrationpreviousconsiderweHerefraction.mole

moledatescalibrationcentralBetweenperiod.recentmosttheaswellasperiods

-4-

givenanyfordatecentralrecentmostTheinterpolation.bycalculatedarefractions

fol-"X"bydesignatedscale""calibrationadefinesprogramourofhistorytheinyear

including,andto,upcalibrationsfor"X97"e.g.year,calendartheofdigits2bylowed

e.g.B,orAanbyqualifiedfurtheris1999forscaleThe1997.indatacentrala

applythatscalesspecialtwobelowdiscussalsoWebelow.discussedas"X99A",

X99NB.andX99NAcalibrations:1999toonly

gasesandgases,referenceunknownanalyzer,APCtheofoperationroutinetheIn

thirdatocomparedaregases","unknownherecalledkindsbothrecalibrated,being

andstandard,principalthetofractionmoleincloseiswhichstandard,secondary

andprincipalthewithcomparisonsfrequentfromknownareindicesJandIwhose

theofdeterminationscircumstances,normalUnderstandards.secondaryspanhigh

calibra-eachofbeginningthenearmadearestandards,twolattertheonbasedRSF,

deter-additionaldays,calibrationlongespeciallyForend.thenearagainanddaytion

thethatassumesroutinelyprogramREFGASTheday.theduringmadeareminations

determi-RSFallofaveragesimpleausingday,calibrationgivenaonconstantisRSF

index.currentunknownofgasesofJ-indicesandI-thecalculatetonations

1999inGasesReferencePrimaryNOAA/CMDLofMeasurementsAnalyzerAPC3.

unknownastreatedgases,referenceprimarynatural-airNOAA/CMDL15The

fiveofeachonstandardssecondaryourtoanalyzerAPCtheoncomparedweregases,

thefrommovedbeenrecentlyhadanalyzerAPCThe1999.July,toAprilfromdays

majoraoftimethetoup1957fromoperatedhaditwherebuildingainlaboratory

newThespace.officeexclusivelyalmosttoconversionandbuildingtheofrenovation

roomwhoseSIO/CDRG,oflaboratoryinstrumentthewasanalyzertheoflocation

lessinresultinglaboratory,oldtheinthanstablelesssignificantlywastemperature

COofrangethewhendays,calibrationOndeterminations.RSFconsistent 2 ofindex

secondaryspanhighandprincipaltheofrangethetocomparablewasgasesunknown

largeThedeterminations.theonaffectminoraonlyhadvariationthisstandards,

-5-

largeinhowever,resulted,gasesNOAA/CMDLofsettheoffractionmoleinrange

COloworhighextremelywithgasesfordaytodayfromdispersions 2 values.index

perfor-calibrationimprovetoJuly),14and(2dayscalibrationfifthandfourththeOn

cali-thetoaddedweregasesreferenceprimarynatural-airSIO/CDRGelevenmance,

APCtheofbehaviornon-linearthepreciselymorecharacterizetoschemebration

indays,twotheofeachonruntherebywerealtogethergasesTwenty-sixanalyzer.

COfractionmoleincreasingoforder 2 crea-thetoledschemecalibratingspecialThis.

"X99NB",and"X99NA"thecalledherescales,calibrationadditionaltwooftion

below.explained,further

ofsetsfordatacalibrationindispersiondaytodaycalculatedthedecreaseTo

J-theadjustsprocedureThisconcordance.""tankcalledprocedureausewegases

basedRSF,theofestimateimprovedanofmeansbydaycalibrationeachofindices

cali-theofdaysalloncommoninrungases,unknowntheofallfromdatatheupon

standards)gasreferenceprimaryNOAA/CMDL15theincludingcase,this(inbration

theofeffectThestandards.secondaryspanhighandprincipalthejustthanrather

nearmeasurementsgasreferencefordispersiondaytodaythereducetoisadjustment

range.fractionmoletheofendshighandlowthe

calibrations,ofdaysfivetheofeachfor1999,inprocedureconcordancetankThe

indifferenceabsolutethedeterminedfirstgases,NOAA/CMDL15theofeachforand

SIO/CDRGtheofJ-indexassignedthebetoselectedvalue,midpointafromJ-index

ofdifferencesabsolutetheofaveragesensembleDailystandard.secondaryprincipal

Thecalculated.thenwereensemble,theofset-averagefive-dayaandgases,15these

thatofratiothebymultipliedthenwasday,eachongas,eachfordifferenceabsolute

concor-tankbymadetherebylattertheaverages,ensembledailythetoset-average

addedthenwasvaluemidpointThedays.calibrationallforsamethebetodance

anproducingday,eachongaseachfordifferences,signedadjustedthetoback

set-averageTheday.eachforgasesNOAA/CMDL15allforJ-indicesofsetadjusted

-6-

meanrootcalculatedthebutprocedure,thisbychangednotisgaseachforJ-index

typicallydeterminationgasindividualantorespectwithDEV)(RMSdeviationsquare

ofdegreesinreductiontheoftakenisaccountafterevenreduced,alwaysalmostis

concordancetankthisBeforeprocedure.concordancetankthebycausedfreedom

ppm.0.280adjustment,after(J-index);ppm0.292wasDEVRMStheadjustment

dailywhenincreasedisnext,demonstrateweasimprovement,smallunusuallyThis

for.correctediscalibrations1999theforRSFindrift

can-butdays,thebetweendispersionreducecanprocedureconcordancetankThe

dayscalibrationfivetheDuringday.eachwithinRSFtheofinstabilityforadjustnot

RSFinvariationa2%,toupbydayeachduringdecreasedfact,inRSF,the1999,in

REF-theSincelaboratory.ourinpreviouslyobservedtypicallythatdoubleleastat

drift-RSFspecialaRSF,driftingaforadjustnotdoesprogramcomputerGAS

linearlywassensitivityinstrumentthewhichininstitutedwasprocedurecorrection

pro-REFGAStheinvokingbeforedeterminationsRSFwithin-daybetweenadjusted

valuesinresultingrecalculated,thenweregaseachforJ-indicesandI-Thegram.

RSF’s".driftingforcompensatetomodified"indicesasdesignated

tankbeforeDEVRMStheprocedure,drift-correctionRSFthisoutcarryingAfter

DEVRMSlatterTheppm.0.106concordance,afterand,ppm0.215wasconcordance

14].page2001,al.,et[Keelingcalibrationspreviousofthattocomparableis

sec-nexttheindiscussedas1999,inoutcarriedthenwasstepcalibrationfinalA

datathefromdeterminedanalyzer,APCtheofresponsenonlinearthedefinetotion,

COprimarySIO/CDRG11theforobtained 2 theonanalyzedgasesreference-in-air

thethathypothesistheonrestsstepfinalthisofsuccessThedays.fifthandfourth

thebygivenequation,responsecubicanalyzerAPCtheofcharacteristicsorderhigher

evendayscalibrationfivetheovervarynotdidcoefficients,cubicandquadratic

vary.didcharacteristics,linearthereflectingRSF,thethough

-7-

COofAssignment4. 2 AirinFractionsMole

standardsprimarySIO/CDRGthetoassignedvaluesfractionmoleManometric

fol-theusing1998,inmanometervolumeconstanttheonmeasuredthoseare1999for

ratiovolumemanometriclowing

V 4 cc

V 5000 cc = (3)1322.30

where V 5000 cc = 5015.09 cc

V 4 cc = 3.7927 cc

onstableremainedhadgasesthethatassumingbyatarrivedwasratiovolumeThis

calibratingX99AtheofbasistheisstabilityofassumptionThis1985.sinceaverage

[2001].al.etKeelinginreportedscale

CObetweenrelationshipcubicfollowingThe 2 (afterJ-indexandfractionmole

deter-thenwasabove)discussedasRSF,driftingaforcompensatetomodification

gasesreferenceprimarySIO/CDRG11theforJ-indicestheofaveragesfrommined

1999:July14and2onobtained

X = Co + C 1J + C 2J 2 + C 3J 3 (4)

Xwhere = COfractionmole 2 ppm)(in

J = ppm)(inJ-index

Co = 86.40013

C 1 = 0.5177722

C 2 = 5.275435×10−4

C 3 = 5.872148×10−7

-8-

scale.""X99NAtheforbasistheisequationcubicThis

2onanalyzerAPCtheofcharacteristicsnonlineartheestablishedthusHaving

tonormalizedwerecalibrationofdaysthreepreviousthefordatatheJuly,14and

procedure,concordancetankusualtheofmodificationaofmeansbydaystwothese

absolutetheadjustedweSpecifically,above.3,Sectionindescribedversionusualthe

ondifferenceabsolutedailyaveragethetodayeachongaseachofdifferenceJ-index

absoluteaveragesetoverallthetothanratherdays,calibrationJuly14and2the

bygivenfactorabyincreasedthuswasdifferenceabsoluteJ-indexEachdifference.

averagesetoveralltheto(42.24)July14and2onlyforaveragetheofratiothe

0.33bydecreasedwasgasfractionmolelowesttheforJ-indexaverageThe(42.12).

ppm.0.36byincreasedhighest,theofthatandprocedurethisusingppm

toconvertedwereprocedureconcordancetankthebyfoundJ-indicestheFinally,

1TableCO2 COthelists1Table(4).equationusingfractionsmole 2 eachoffractionsmole

gaseachforaveragesthewithalongday,eachondeterminedgasreferenceprimary

deviations,standardtheanddays,fivetheover si determina-day’sindividualanof,

thethroughfreedomofdegreesoflosstheaccountintotakingDEV,RMSThetions.

furtherWeJ-index.inppm0.106betocalculatedisprocedure,concordancetank

COthedeterminedwhichrelationshipcubicalternativeantested 2 theoffractionsmole

polynomicalcubicdifferentusingseparately,July14and2ongasesNOAA/CMDL

wereaverage,onthat,fractionsmoleyieldedworkupThisday.eachforequations

theusingcalibrations,ofdays5fulltheforcalculatedthanJuly2onlowerppm0.02

calculationpreviousthefromunchangedwasJuly14foraverageThescale.X99NA

individualfordifferworkupsX99NA-scaleandseparate-dayThedays.bothover

thewhichforgas,NOAA/CMDLhighesttheforexceptppm,0.13thanlessbygases

ppm.0.27isdifference

-9-

CONOAA/CMDLandSIO/CDRGofSummary5. 22 1991-1999Fractions,Mole

2Tablecalibra-analyzerAPCofperiodsfourfromdataSIO/CDRGcompares2Table

columnsofsettheinlisted1999,For1999.inreporteddataNOAA/CMDLtotions

COtheindifferenceaveragethe2,Tableinrightfartheto 2 15offractionsmole

SIO/CDRGppm,0.01isNOAA/CMDLand1)Table(seeSIO/CDRGbetweengases

(deviationstandardtheandlower, si ppm.0.13isdifferenceindividualanof)

SIO/CDRGatcalibrationsanalyzerAPConbaseddataare2TableinlistedAlso

22fromcalibrationsofdays16to(131991-1993inmadegases,NOAA/CMDLtheof

13fromcalibrationsofdays(61995-1996in1993),March11to1991January

toJuly28fromcalibrationsofdays(51997inand1996)July26to1995December

notwereperiodscalibrationthesefromdataanalyzerAPCThe1997).September,23

pri-SIO/CDRGofusedirecttorespectwithorvariation,RSFwithin-dayforadjusted

procedureconcordancetankThedata.1999thewereascalibration,theingasesmary

cali-cubicTheabove).3,Section(seeJ-indicesaverageperiodtheoneffectnohad

REFGASthe(fromJ-indicesconverttoused1997,through1991forequationsbration

COtobase)data 2 reportedasscale,calibrationX99Atheonbasedarefractions,mole

manometricthethatabove,4Sectioninnotedasassuming,[2001],al.etKeelingin

averageonremainedgasesreferenceprimarySIO/CDRGtheoffractionsmole

(dispersionlargerelativelytheisNotable1999.to1985fromunchanged si 0.19=

(0.11differenceaveragelargesttheexhibitalsowhichresults,1991-1993theforppm)

onlytheareresults1991-1993TheNOAA/CMDL.andSIO/CDRGbetweenppm)

COindriftdifferentialsignificantpossiblyofevidence 2 thebetweenfractionmole

calibra-fourallfromdatatheTakinggases.primarySIO/CDRGandNOAA/CMDL

thetodifferencesaveragetheoffitlinearaofslopetheaccount,intoperiodstion

driftlinearupwardanimpliesslopeTheppm/year.0.015isanalysisofdatesaverage

gasesreferencestandardprimaryNOAA/CMDL15theforyears10inppm0.15of

1991-1993thetodueisdrifttheofmostalthoughgases,SIO/CDRGthetorelative

-10-

data.

COtoconvertedare1999fordataanalyzerAPCtheIf 2 theusingfractionsmole

betweendifferenceaveragethescale,X99NAspecialtheofinsteadscaleX99A

Thehigher.SIO/CDRGppm,0.05is1999inNOAA/CMDLandSIO/CDRG si is

calibrationfivethebetweendispersionhightomainlyduevaluehighthisppm,0.41

range.concentrationtheofendshighandlowtheneargasesreferencethefordays

gasesNOAA/CMDLsevenofsubsettheforresultsaverageshowsalso2Table

averageThe1999.inSIO/CDRGatcalibratedmanometricallyalsobeenhadthat

fulltheofthosewithcloselyagreesubsettheofdeviationsstandardanddifferences

set.fulltherepresentedwellsubsetthethataffirmingset,

3Tableausing2,Tableinpresenteddatatheofanalysisalternativeanpresents3Table

tomeasurementsanalyzerAPCconverttoscale,X99Bthescale,calibratingdifferent

constantapositsscaleX99BThe2001].Addendum,al.,et[Guentherfractionsmole

primarytheofconstancythanrather1999,to1985forCMMtheinratiovolume

et[KeelingscaleX99Atheformulatinginassumedwasthatstandardsgasreference

chambercc4ofaveragethebydefinedisratiovolumeconstantThe2001].al.,

1990,and1988,1985-1986,inmadecalibrationsvolume

V 4 cc

V 5000 cc = (5)1321.18

where V 5000 cc = 5015.09 cc

V 4 cc = 3.7959 cc

TableinlistedarescaleX99BthedefinethatequationspolynomialcubicofsetThe

scale,X99NBadefineadditionallyWe[2001].Addendumal.,etGuentherofA4

thefromcalculatedequationpolynomialcubicawithscale,X99NAthetoanalogous

standardsgasreferenceairprimarySIO/CDRGtheoffractionsmolemanometric

(5),equationingivenratiovolumeCMMtheusingcalculatedand1998inmeasured

-11-

Thescale.X99AtheformulatetousedJ-indicesofsetsamethewithcombined

follows:asdefinedisequationpolynomialcubicX99NB

X = Co + C 1J + C 2J 2 + C 3J 3 (6)

Xwhere = COfractionmole 2 ppm)(in

J = ppm)(inJ-index

Co = 86.47370

C 1 = 0.5182131

C 2 = 5.279927×10−4

C 3 = 5.877148×10−7

thecausesratio,volumeCMMconstantauponbasedscale,X99BThe

periodtheduringdriftupwardanreflecttogasesreferenceprimaryNOAA/CMDL

periodsfourthefordifferencesaveragetheoffitlinearaofslopeThe1999.to1991

anorppm/year,0.051isanalysisofdatesaveragethetoSIO/CDRGatcalibrationof

10inppm0.51ofgasesreferenceprimaryNOAA/CMDL15theofdriftlinearupward

years.

ScalesCalibrationNOAA/CMDLandSIO/CDRGofComparison6.

theoffractionsmolebetweenyearsdifferentfordifferencesaverageThe

manometri-andSIOatanalysisinfraredbydeterminedgases,referenceNOAA/CMDL

thethatindicatescale,X99Atheonbased2TableinlistedasNOAA/CMDLbycally

thanmoreby1999to1991fromdifferentiallydriftednothavescalescalibrationtwo

inuse,thefromdirectlyresultsconclusionThisresult.satisfactoryhighlyappm,0.1

constant-SIO/CDRGtheofratiovolumethewhichinscaleaofcomparison,this

zerowithconsistentbetocalculatedwas(CMM)manometermercury-columnvolume

driftzeroThis1985.afterstandardsgasreferenceSIO/CDRGtheindriftaverage

-12-

COprimary10toappliesassumption 2-in-N2 CO11theaswellasstandards 2-in-air

et[KeelinggasesNOAA/CMDLtheofcalibrations1999theindirectlyusedstandards

betweendriftdifferentialnoessentiallywastherethatfoundweHowever,2001].al.

COSIO/CDRGofsetsthe 2-in-N2 COand 2 couldscaleX99Athethatsogases,-in-air

COtheofstabilitytheononlybasedbeenhavewellas 2 gases.-in-air

thebetweenagreementabsoluteofdegreetheisaddresstoissueadditionalAn

1998forconsideredbestiswhichscales,calibrationNOAA/CMDLandSIO/CDRG

indicates2Tableout.carriedwereintercalibrationsintensemostthewhen1999and

aNOAA/CMDL,thanlowerppm0.01fractionsmoleproducesscaleX99NAthethat

ofratiovolumemanometric1998theifonlyvalidbutresult,satisfactoryhighly

average.ondriftnotdidgasesSIO/CDRGtheifandperiod,thatforcorrectis1322.30

moleofcalibrationabsolutetheofestimatesadditionthreeprovideSIO/CDRGofData

COoffraction 2 ofchambercc5000theofvolumetheestimatestheseofallIn-in-air.

chambercc4theofvolumethebutcc,5015.09ofvaluetheassignedisCMMthe

(V 4 cc estimates,fourTheevidence.ofvarietyaonbasedvaluesdifferentassignedis)

oforderdescendinginlistednoware2Tableofthatincluding V 4 cc .

estimate.ECM:1.

COofsamplesarchivedofMeasurements 2 ConstantElectronicanonwaterseafrom

COofaliquotsoftransfersbycalibrated(ECM),ManometerVolume 2 plenumsfrom

sam-sametheofmeasurementspreviouswithcomparedwhenwater,withcalibrated

gives:CMM,theusingples

V 4 cc = 3.7961 cc.

scale).(X99BestimateplenumDirect2.

1990and19881985,inCMMtheofchambercc4theofcalibrationswithConsistent

COofaliquotsoftransferson(based 2 theinusedplenumscalibratedsamethefrom

thatmadeisassumptionthemercury),withcalibratedbutestimate,first V 4 cc

-13-

whence:1999tounchangedremained

V 4 cc = 3.79593 cc.

estimate.basedNOAA/CMDL3.

primarytheirofcalibrationsmanometricNOAA/CMDLthethatassumptiontheOn

1999ingasestheseof7onmeasurementsmanometricourcorrectaregasesreference

gives:

V 4 cc = 3.7944 cc.

scale).(X99AestimatefractionmoleStable4.

there-and1985,afterdriftnotdidgasesreferenceprimaryourthatassumptiontheOn

thatfore V 4 cc measure-manometricour2),Tableforbasis(the1990afterdecreased

2:estimateofinsteadgive,1999ingasestheseofments

V 4 cc = 3.7927 cc.

1999theonbasedishowever,ECM,ourofusemakeswhich1,estimateVolume

onbasedare4and2estimateswhereaswater,usingvolumesplenumofcalibration

Onlyplenums).ofusenomakes3(Estimatemercury.withcalibratedplenumsthe

calibrationsmercuryandwaterthebothinemployedwere7and6,3,numbersplenum

thethatindicatesplenumsthesefordataofweight-averageThevolumes.chamberof

determinedasthanlowercc0.00147beshouldvolumechambercc4water-calibrated

watertheIf2001].al.,et[Guenthervolumesplenummercury-calibratedtheusing

theofbasisthe2,estimateforcalibrationmercurytheofplaceinusediscalibration

result:thehavewescale,X99B

water:usingCMMofestimateplenumDirect5.

V 4 cc = 3.79446 cc.

-14-

NOAA/CMDLtheonbased3,estimatewithagreementsatisfactoryveryin

mercury,formediumcalibratingaaswaterSubstitutingscale.calibrationmanometric

magni-sametheofdisagreementatohowever,leads,scale,X99Athetoappliedwhen

2.Tableinshownagreementabsolutegoodtheofplaceintude

molecalculatedinrangeaproducescc,3.7927tocc3.7961values,ofrangeThe

NOAA-basedTheppm.350offractionmoleawithgasaforppm0.32offraction

esti-fourtheoflowestandhighestthebetweenwayhalfapproximatelyliesestimate

with(associatedestimatefourththeacceptedprovisionallyhavewenowUntilmates.

aevidence,otherofabsencetheinbecause,scale,preferredourasscale)X99Athe

reflectshouldgasesSIO/CDRGandSIO/CDMLthebetweendriftdifferentialsmall

gases.referencestandardprimaryofseteitherbydriftabsolutelittle

thatfindingdecisiveabetoappearswhatwithhowever,confronted,areWe

V 4 cc toAddendumanindescribedas1999,to1991fromsignificantlydriftnotdid

ofreanalysisofbasistheOn2001].al.,et[Guentherreportcalibrationmainour

cc4theofratedrifttheestimate),firstthe(seeECMtheusingsamplesarchived

standardthetosimilarvalueacc/year,0.000103byupwardbetofoundischamber

isscaleX99Athebyimplieddriftthewhereascc;0.000082ofslopetheoferror

cc((3.7961cc/yr0.00034ofdriftdownwardatoequivalent − cc)3.7927 ÷ ayr),10

esti-theFurthermore,slope.theoferrorstandardthetimes5isthatrateindifference

ofmate V 4 cc cc0.0002withinagreesabove),estimate(firstmethod,ECMtheby

determinedwellthewithppm),350offractionmoleaforppm0.02to(equivalent

above.estimate,second

changingorgasesreferencedriftingpossibilities,twobyconfrontedthusareWe

differentialsmallthewithoddsatbetoappearsformerTheCMM.ofperformance

totenddataECMthebutgases,NOAA/CMDLandSIO/CDRGbetweenfounddrift

wasmanometerthebutdriftedgasestheIfvolume.chambercc4driftingaoutrule

andsecondthird,andfirstthecomparingbygivenisdisagreementabsolutethestable,

-15-

indiscrepancyaestimates,thirdandfifthorthird, V 4 cc (0.15cc,0.0016aboutof

bothofgasestheIfless.or1999)inlowerscaleNOAA/CMDLppm,350atppm

aindicatingapply,estimatesfourthandthirdthedrift,offreealmostarelaboratories

possiblealsoisItdirection.oppositetheinmagnitudesamethealmostofdiscrepancy

manometertheandgasestheboththatmeasurements,ourofprecisionthewithin

itreplacetopresentatprospectnowithandCMM,ourofrestorationWithoutdrifted.

evi-thisresolvetoexperimentsoncarrytounablearewedeviceanotherwithSIOat

reportingforscaleprovisionalnewaestablishingondecisionAdilemma.dent

COatmosphericSIO/CDRG 2 pending.isdata

-16-

References

COPrimaryNOAAofAnalysesManometricKeeling,D.C.andR.P.Guenther, 2

Monitor-ClimatetosubmittedReportTechnicalSIO,atStandardsGasReference

2000.16,MarchNOAA,Laboratory,Diagnosticsanding

CalibrationGasReferenceScrippsKeeling,D.C.andEmanuele,G.R.,P.Guenther,

Standards:Dioxide-in-airCarbonandDioxide-in-NitrogenCarbonforSystem

Calibrations1985-1999ofFormulationAlternateAddendum:1999,ofRevision

Manometer,MercuryofVolumeChambercc4ofRe-calibrationafter Refer-SIO

Seriesence 2001.01-11,No.

Moss,J.D.andBollenbacher,A.Emanuele,G.Guenther,R.P.D.,C.Keeling,

andDioxide-in-NitrogenCarbonforSystemCalibrationGasReferenceScripps

1999,ofRevisionStandards:Dioxide-in-airCarbon SeriesReferenceSIO No.

2001.01-11,

forsystemmanometricprecisionhighAThoning,W.K.andTans,P.P.L.,C.Zhao,

COofcalibrationsabsolute 2 air,dryin ResearchGeophysicalofJournal Vol.,

1997.D5,No.102,

CO

NO

AA

/CM

DL

of19

99in

mea

sure

men

tsin

frar

edSI

O/C

DR

G1.

Tab

le2

stan

dard

s,ga

sre

fere

nce

prim

ary

-in-

air

CO

assc

ale

X99

NA

inex

pres

sed

2pp

m.

infr

actio

nsm

ole

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.N

o.C

yl.

No.

Cyl

.A

naly

sis

132

107

123

106

101

146

136

105

139

103

121

130

111

102

110

Dat

e

521.

0345

2.95

423.

1941

2.24

396.

4038

9.74

381.

4236

9.43

360.

9435

3.25

349.

3733

7.34

323.

9030

4.16

246.

5521

-Apr

-99

520.

8745

3.05

423.

1541

2.16

396.

4238

9.71

381.

4236

9.48

360.

9035

3.08

349.

3333

7.25

323.

8930

4.24

246.

643-

Jun-

9952

0.63

453.

0542

3.20

412.

2229

6.41

389.

6438

1.54

369.

5236

1.07

353.

3934

9.49

337.

3132

3.97

304.

2724

6.25

28-J

un-9

952

1.31

453.

1942

3.27

412.

2139

6.42

389.

6138

1.34

369.

3936

0.89

353.

2534

9.33

337.

2132

3.92

304.

2724

6.74

2-Ju

l-99

521.

3645

3.08

423.

0941

2.09

396.

2938

9.57

381.

3036

9.34

360.

8335

3.14

349.

3033

7.20

323.

9430

4.29

246.

3514

-Jul

-99

521.

0445

3.06

423.

1841

2.18

396.

3938

9.65

381.

4036

9.43

360.

9335

3.22

349.

3633

7.26

323.

9330

4.24

246.

50A

vera

ge0.

310.

080.

060.

060.

060.

070.

090.

070.

090.

120.

080.

060.

030.

050.

20St

Dev

-17-

NO

AA

/CM

DL

of19

99,

to19

91fr

oman

alys

es,

infr

ared

SIO

/CD

RG

and

man

omet

ric

NO

AA

/CM

DL

ofC

ompa

riso

n2.

Tab

leC

Oas

scal

esX

99N

Aan

dX

99A

inex

pres

sed

stan

dard

s,ga

sre

fere

nce

prim

ary

2pp

m.

infr

actio

nsm

ole

year

by(S

IO/C

DR

G–N

OA

A/C

MD

L),

Dif

fere

nces

and

Res

ults

SIO

/CD

RG

a

1992

Cyl

inde

rd

1996

d19

97d

1999

d19

99e

No.

bN

OA

A/C

MD

Lc

Dif

f.SI

OD

iff.

SIO

Dif

f.SI

OD

iff.

SIO

Dif

f.SI

O

-0.0

924

6.50

1.07

247.

660.

0224

6.61

-0.0

324

6.56

0.12

246.

7124

6.59

110*

-0.1

530

4.24

0.12

304.

51-0

.13

304.

26-0

.04

304.

350.

0530

4.44

304.

3910

2-0

.03

323.

930.

0232

3.98

0.01

323.

970.

0432

4.00

0.09

324.

0532

3.96

111*

-0.0

133

7.26

-0.0

833

7.19

-0.0

333

7.24

0.01

337.

280.

0233

7.29

337.

2713

00.

0134

9.36

-0.1

334

9.22

0.01

349.

360.

0334

9.38

0.00

349.

3534

9.35

121

-0.1

535

3.22

-0.3

135

3.06

-0.1

935

3.18

-0.1

435

3.23

-0.1

935

3.18

353.

3710

30.

0136

0.93

-0.1

936

0.73

-0.0

236

0.90

-0.0

436

0.88

-0.1

436

0.78

360.

9213

9*0.

0836

9.43

-0.1

636

9.19

0.11

369.

460.

0436

9.40

-0.0

436

9.31

369.

3510

5*0.

0738

1.40

-0.1

838

1.15

0.07

381.

40-0

.04

381.

29-0

.08

381.

2538

1.33

136*

0.15

389.

65-0

.10

389.

400.

1338

9.63

0.12

389.

62-0

.02

389.

4838

9.50

146

0.05

396.

39-0

.20

396.

14-0

.01

396.

33-0

.08

396.

26-0

.13

396.

2239

6.34

101*

0.16

412.

18-0

.04

411.

980.

1241

2.14

0.06

412.

08-0

.10

411.

9241

2.02

106

0.15

423.

180.

0142

3.04

0.07

423.

100.

0042

3.03

-0.1

542

2.88

423.

0312

3-0

.16

453.

06-0

.04

453.

18-0

.15

453.

07-0

.22

453.

00-0

.50

452.

7245

3.22

107*

-0.2

652

1.04

0.98

522.

280.

2752

1.57

0.07

521.

37-0

.53

520.

7752

1.30

132

-0.0

10.

050.

02-0

.01

-0.1

115

ofA

v.s i

0.13

0.41

0.12

0.09

0.19

7of

Av.

f-0

.01

0.05

0.00

-0.0

5-0

.10

s i0.

090.

460.

080.

090.

20

Not

es:

ada

tes)

.in

clus

ive

for

text

,of

5Se

ctio

n(s

eeSI

O/C

DR

Gat

mea

sure

men

tsan

alyz

erA

PCof

peri

ods

tore

fer

Yea

rsb

omitt

ed).

103

(cyl

inde

rst

ars

bysh

own

1999

,in

SIO

/CD

RG

byan

alyz

edm

anom

etri

cally

wer

eth

atst

anda

rds

ofSu

bset

cN

OA

A/C

MD

L.

byre

port

edm

easu

rem

ents

Man

omet

ric

dsc

ale.

calib

ratio

nX

99A

usin

gfr

actio

nsm

ole

toco

nver

ted

mea

sure

men

tsan

alyz

erA

PCSI

O/C

DR

Ge

scal

e.X

99N

Aus

ing

frac

tions

mol

eto

conv

erte

dan

dre

port

,th

isin

desc

ribe

das

adju

sted

1999

,in

mea

sure

men

tsan

alyz

erA

PCSI

O/C

DR

Gf

aste

risk

s.w

ithT

hose

-18-

NO

AA

/CM

DL

of19

99,

to19

91fr

oman

alys

es,

infr

ared

SIO

/CD

RG

and

man

omet

ric

NO

AA

/CM

DL

ofC

ompa

riso

n3.

Tab

leC

Oas

scal

esX

99N

Ban

dX

99B

inex

pres

sed

stan

dard

s,ga

sre

fere

nce

prim

ary

2pp

m.

infr

actio

nsm

ole

year

by(S

IO/C

DR

G–N

OA

A/C

MD

L),

Dif

fere

nces

and

Res

ults

SIO

/CD

RG

a

1992

Cyl

inde

rd

1996

d19

97d

1999

d19

99e

No.

bN

OA

A/C

MD

Lc

Dif

f.SI

OD

iff.

SIO

Dif

f.SI

OD

iff.

SIO

Dif

f.SI

O

0.12

246.

711.

2824

7.87

0.23

246.

820.

1224

6.71

0.17

246.

7624

6.59

110*

0.11

304.

500.

3830

4.77

0.12

304.

510.

1630

4.55

0.11

304.

5030

4.39

102

0.24

324.

200.

2932

4.25

0.28

324.

240.

2532

4.21

0.16

324.

1232

3.96

111*

0.28

337.

550.

2133

7.48

0.26

337.

530.

2333

7.50

0.09

337.

3633

7.27

130

0.31

349.

660.

1734

9.52

0.30

349.

650.

2634

9.61

0.07

349.

4234

9.35

121

0.15

353.

52-0

.01

353.

360.

1135

3.48

0.09

353.

46-0

.12

353.

2635

3.37

103

0.31

361.

230.

1136

1.03

0.28

361.

200.

2036

1.12

-0.0

636

0.86

360.

9213

9*0.

4036

9.75

0.15

369.

500.

4236

9.77

0.28

369.

630.

0436

9.39

369.

3510

5*0.

4038

1.73

0.14

381.

470.

3938

1.72

0.21

381.

540.

0038

1.33

381.

3313

6*0.

4938

9.99

0.22

389.

720.

4638

9.96

0.38

389.

880.

0638

9.56

389.

5014

60.

3939

6.73

0.14

396.

480.

3239

6.66

0.18

396.

52-0

.04

396.

3039

6.34

101*

0.52

412.

540.

3141

2.33

0.47

412.

490.

3341

2.35

-0.0

141

2.01

412.

0210

60.

5142

3.54

0.37

423.

400.

4242

3.45

0.27

423.

30-0

.06

422.

9742

3.03

123

0.23

453.

450.

3445

3.56

0.23

453.

450.

0845

3.30

-0.4

045

2.82

453.

2210

7*0.

1852

1.48

1.42

522.

720.

7152

2.01

0.41

521.

71-0

.41

520.

8952

1.30

132

0.31

0.37

0.33

0.23

-0.0

315

ofA

v.s i

0.14

0.41

0.15

0.10

0.18

7of

Av.

f0.

300.

350.

310.

19-0

.02

s i0.

110.

420.

070.

070.

19

Not

es:

ada

tes)

.in

clus

ive

for

text

,of

5Se

ctio

n(s

eeSI

O/C

DR

Gat

mea

sure

men

tsan

alyz

erA

PCof

peri

ods

tore

fer

Yea

rsb

omitt

ed).

103

(cyl

inde

rst

ars

bysh

own

1999

,in

SIO

/CD

RG

byan

alyz

edm

anom

etri

cally

wer

eth

atst

anda

rds

ofSu

bset

cN

OA

A/C

MD

L.

byre

port

edm

easu

rem

ents

Man

omet

ric

dsc

ale.

calib

ratio

nX

99B

usin

gfr

actio

nsm

ole

toco

nver

ted

mea

sure

men

tsan

alyz

erA

PCSI

O/C

DR

Ge

scal

e.X

99N

Bus

ing

frac

tions

mol

eto

conv

erte

dan

dre

port

,th

isin

desc

ribe

das

adju

sted

1999

,in

mea

sure

men

tsan

alyz

erA

PCSI

O/C

DR

Gf

aste

risk

s.w

ithT

hose

-19-