First Expendable Bathythermograph Science Workshop

FirstExpendableBathythermographScienceWorkshop

WorkshopReport

Preparedby:MollyBaringer,GustavoGoni,JanetSprintall,withcontributionsfromtheworkshopparticipants.Melbourne,AustraliaJuly7‐8,2011AustralianBureauofMeteorologyHeadquartersBuilding700CollinsStreet,DocklandsRoom3,6thfloorWorkshophostedbyGraemeBallandLisaKrummelattheAustralianBureauofMeteorology(ABOM)).ItwasmoderatedbyMollyBaringer(AOML),LisaKrummel(ABOM),GraemeBall(ABOM)andAnnThresher(CSIRO).RapportuerssummarizingindividualsessionswereJanetSprintall,RebeccaCrowley,PedroDiNezioandTimBoyer(NOAA/NODC).TheworkshopwasattendedbyscientistsfromAustralia,SouthAfrica,France,Numea,UnitedKingdom,UnitedStates,andJapan.

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Introduction.............................................................................................................................. 3TheXBTNetwork ..............................................................................................................................4Theworkshopformat ......................................................................................................................7

XBTSciencepresentations................................................................................................... 7DayOne.............................................................................................Error!Bookmarknotdefined.DayTwo:...........................................................................................Error!Bookmarknotdefined.

GeneralDiscussions .............................................................................................................14FundingandResearchv.Operations....................................................................................... 14LogisticalIssues.............................................................................................................................. 14ThefutureofXBTtransects........................................................................................................ 17OnclimatequalityXBTdata ....................................................................................................... 15XBTScienceSteeringTeam ........................................................................................................ 16

Summary ..................................................................................................................................18WorkshopAgenda.................................................................................................................20

ListofParticipants................................................................................................................24

Acronyms .................................................................................................................................27

IntroductionThegoalofthemeetingwastobringtogetherscientiststohighlighttheusesofXBTdata.Topicsincludedupperoceanheatbudgets,transport,circulation,andvariabilityofnearsurfacetemperatureandsalinity.TheuseofmultipledatatypeswasencouragedtocontainnovelinclusionsofdifferentinstrumentsandwasnotstrictlylimitedtoXBTobservationsalone.

• AbstractsubmissionswereencouragedforpresentationsonanytopicandanyregionoftheoceansprovidedthatsubstantialuseofXBTdatawasmade.ThegoalofthemeetingwastoassessthegeneralutilityoftheXBTdataanditsfuturedirection;

• Heatbudgetsonglobaltoregionalscales;• Seasonaltointer‐annualvariabilityoftheupperoceanasobservedbyXBTs

andotherinstruments;• TheroleofXBTsandotherupperoceanthermalmeasurementsin

constrainingoceandataassimilationfields;• Estimationofcirculationfieldsonglobaltoregionalscales;• Futureofresearchandoperations,and

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• Newtechnology,toincludechangestotheoperationabilitiesofanXBT,andfall‐rateestimation.

ThemeetingtookplaceattheAustralianBureauofMeteorologicalHeadquartersinMelbourne,Australiaon7‐8July,2011.Theworkshopwasdividedinoralpresentationsandplenarydiscussions,heldwiththeobjectiveofexchangingideasonhowtoproceedwiththeimplementation,maintenance,andenhancementoftheXBTNetwork.

TheXBTNetworkXBTsarevaluablebecausetheyrepresentthelargestfractionofthetemperatureprofileobservationssince1970sanduntilthefullyimplementationofArgoprofilingfloatsinapproximately2005.Inrecentyears,approximately25,000XBTaredeployedeachyear,ofwhicharound15,000reachtheGTSinreal‐time,representingcloseto15%ofthecurrenttotalupperoceanthermalprofileobservations.Currently,studiesperformedusingdatafromXBTobservationsarefocusedon,butnotlimitedto:a)variabilityofsurface,subsurface,currentsandundercurrents,b)meridionalheattransport,andc)thermaltemporalvariabilityalongfixedtransects.MostoftheXBTtransectsarecurrentlybeingusedtostudythevariabilityofseveralsurface,subsurface,boundary,andundercurrents,someofwhichhavebeenmonitoredformorethan20years.Thereare49XBTtransectsrecommendedbythescientificcommunity(Figure1,Gonietal,OceanObs09,ShipOfOpportunityProgram,2011)inHighDensity(alsoreferredasHighResolution)andFrequentlyRepeatedmodes.HighDensitytransectsareoccupiedatleast4timesperyearXBTdeployedatapproximately25kmintervalsalongtheshiptrack.Frequentlyrepeatedtracksareoccupiedataround18timesperyearwithXBTdeploymentsat100kmintervals.LowDensitymodehasbeenlargelydiscontinuedinfavorofArgoprofilingfloatdeployments.TheXBTnetworkisverycomplextomaintainforwhichastrongcollaborationbetweenmanyorganizationsandcountriesareneeded.TheparticipantsrecognizedthatthelogisticsandproblemslinkedtoimplementationoftheXBTnetworkareuniquebutwithsomecommonaspectswithotherobservationalplatforms,discussedthedistinctivecontributionprovidedbyXBTsthatcannotbeaccomplishedbyanyothernetworkofobservations,andhighlightedthesynergythatexistsbetweenXBTobservationsandobservationsfromotherplatforms,suchasaltimetry,surfacedrifters,Argo,etc.

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Figure1.RecommendedXBTtransects.Currently,themainfocusoftheXBTnetworkistomaintaintheHighDensitytransects.ThestrengthoftheXBTdatasetcurrentlyliesonitslengthandonitsabilitytoestimatetransportsacrossentireoceansectionsandkeychoke‐points,suchasDrakePassage,IndonesianThroughflow,ACCsouthofAfrica,etc.ThescientificobjectivesofHDaresummarizedbelow:

• Measuretheseasonalandinterannualfluctuationsinthetransportofmass,heat,andfreshwateracrosstransectswhichdefinelargeenclosedoceanareasandinvestigatetheirlinkstoclimateindexes.

• Determinethelong‐termmean,annualcycleandinterannualfluctuationsoftemperature,geostrophicvelocityandlarge‐scaleoceancirculationinthetop800moftheocean.However,insomeregions,XBTsreaching800mcannotdepictthecompleteverticalstructuresoffinebutintenseoceanicjetsandacombinedapproachintermsofhighdensityanddeeperprofilingfloatmeasurementsisnecessary.

• Obtainlongtime‐seriesoftemperatureprofilesatapproximatelyrepeatedlocationsinordertounambiguouslyseparatetemporalfromspatialvariability.

• Determinethespace‐timestatisticsofvariabilityofthetemperatureandgeostrophicshearfields.

• Provideappropriateinsitudata(togetherwithArgoprofilingfloats,tropicalmoorings,air‐seafluxmeasurements,sealeveletc.)fortestingoceanandocean‐atmospheremodels.

• DeterminethesynergybetweenXBTtransects,satellitealtimetry,Argo,andmodelsofthegeneralcirculation.

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• Identifypermanentboundarycurrentsandfronts,describetheirpersistenceandrecurrenceandtheirrelationtolarge‐scaletransports.

• Estimatethesignificanceofbarocliniceddyheatfluxes.Themainsurfaceandsubsurfacecurrent,undercurrent,andcountercurrentsystemscurrentlybeingmonitoredandstudiedbyXBTtransectsare(theyearmeasurementsbeganareinparenthesis).

• UpstreamKuroshioCurrent:o Upstream:PX44(since1991)o Downstream:PX05(2009)

• GulfStream:AX10(1997),AX32(1981) • AgulhasCurrent:IX21• EastAustralianCurrent:

o at27°S:PX30(1991)o at33°S:PX34(1991)

• EastAucklandCurrentandTasmanoutflow:PX06(1986)• CaliforniaCurrentSystem:

o Undercurrent:PX37(1991)o CaliforniaCurrent:PX37(1991)

• AlaskaCurrent:PX38(1993)• LeeuwinCurrent32°S:IX15(1987)• IndonesianThroughflow:IX01(1987)• SolomonSeacurrentsystem:PX05(2009)• AntarcticCircumpolarCurrent

o SouthofTasmania:IX28(1993)o DrakePassage:AX22(1996)o SouthofSouthAfrica:AX25(2004)

• BrazilCurrent:AX97(2004)• Brazil/MalvinasConfluence:AX18(2002)• AgulhasCurrentat28°S:IX21(1994)• BenguelaCurrentandAgulhasCurrentRings:AX18(2002)andAX08

(2000)• AtlanticOceanEquatorialCurrentSystem:AX08(2000),AX20(2010)• FloridaCurrent:AX7(1997)• NorthAtlanticDriftCurrent:AX01(1997)• LabradorCurrent:AX02(2010)

Inaddition,theuseofXBTobservationsinHighDensitymodetomonitorMeridionalHeatTransport(MHT)intheAtlanticandPacificbasinswerealsohighlighted:

• AX07:MHTintheNorthAtlanticOcean;• AX18:MHTintheSouthAtlanticOcean;and• PX37/40:MHTintheNorthPacificOcean

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TheimplementationoftheXBTtransectsandofdatamanagementrequirementsisdonebytheWMO‐IOCShipOfOpportunityProgrammeImplementationPanel(SOOPIP).AlthoughtheSOOPIPimplementsdatamanagementpractices,theyareusuallynotuniformaseachLaboratoryandcountrycurrentlysetsupproceduresthatarenotstandardizedacrossthenetwork.

WorkshopformatThisworkshopwasorganizedbroadlyintosimilarsciencetopicssuchastheuseofXBTobservationstounderstandoceancirculation,boundarycurrents,heattransportandheatcontentchanges.Interspersedinthesciencepresentationswerediscussions.Belowisasummaryofthesciencepresentationsfollowedbyasummaryofallthediscussions.Abstractsforthepresentationsareincludedintheworkshopwebpage:

XBTSciencepresentationsOurknowledgeinoceancirculation,heatcontent,andmeridionalheattransporthasbeenimpactedthroughtheuseofXBTobservations,whichisreflectedbythelargenumberofscientificpublicationsandthatwerehighlightedinseveralpresentationsmadeattheworkshop.ThemeetingwasopenedbyMollyBaringerwhoprovidedanintroductiontoscienceresultsderivedfromXBTs.ThisintroductionalsoemphasizedthatthemeetingwaspatternedaftertheArgosciencemeetingsandthatitwasasteptowardsbuildingontheXBToperationalbaseintoamorescience‐orientedfocus.AsummaryofscientificapplicationsoftheXBTswaspresented,emphasizingontheHighDensityandFrequentlyRepeatedtransects,whicharefocusedonthemonitoringofmesoscalefeatures,westernboundarycurrents,meridionalheattransport,andthesynergywithotherobservingsystems,suchasArgoprofilingfloats.AsummarypresentationonseveraloceancirculationstudiesandheatandmasstransportswasmadebyDeanRoemmich.ItwasrecommendedthatXBTsbeputforthastheexistingboundarycurrentmonitoringsystemuponwhichotherinstrumentationsuchasgliderscanbuild.WithinthisareaofstudyitwasindicatedthattheHighDensityXBTtransectsareunderappreciatednetworksforsamplingboundarycurrents.Argodataiscomplementaryinthatitcanprovidereferencelevelvelocities.However,XBTsarenotlimitedtoboundarycurrents,theyalsomeasureintotheoceaninterior.TimeseriesofboundarycurrenttransportestimatesusingXBTswerepresented,whichincludedtheEastAucklandcurrentwhereArgodataaretoosparsetodefinethecurrent,andtheCaliforniaCurrentsystemwheretheCalCOFI(CaliforniaCooperativeFisheriesInvestigations)programprovidesadditionaltransportcalculations,butnotgranularandoffshore

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enough.AsummaryofestimatesofheatandmasstransportfromXBTdatawasalsopresented.Ingeneral,altimetrysatelliteobservationswereidentifiedasthebestdatasettocomplementXBTdatawhenthereislackoftemporalcoverage.OceanCurrentsAsummaryofthemonitoringandanalysiseffortsofthenorthernlimbofthesubtropicalgyreusingHDXBTtransectsintheSouthPacificOceanwaspresentedbyAlexGanachaud.Highlyvariabletransportestimates(25‐30Sv)weredeterminedfromthebiannualXBTtransect(7surveyssince2008)betweenNewCaledonia–Vanuatu–SolomonIslands(roughlythesouthernportionofPX04/05)thatcrossesthenorthernlimboftheSouthPacificsubtropicalgyre.TheNorthVanuatuJetwasassociatedwithvariousnarrowwestwardstreamsimpactedbytopographyandwindvariability,whiletheeastwardflowingSouthEquatorialCounterCurrentexhibitedstrongseasonality.Thecurrentsarecharacterizedbystrongdeepshearto1000m,supportingtheneedfordeploymentofthedeeper‐reachingT‐5XBTprobestoadequatelyresolvethegeostrophicflowandtransportatthesedepths.ThecontinuanceofFrenchfundingforthisXBTtransectisuncertainatpresent,yetitprovidesimportantinformationabouttheCoralSea/SolomonSeacirculationsystemthatarethefocusoftheCLIVAR‐endorsedSouthwestPacificOceanCirculationandClimateExperiment(SPICE).AstudyofdecadalChangesintheEastAustralianCurrentsystemandtheirrelationshiptochangesintheSouthPacificGyrewaspresentedbyKatyHill.Threelong‐running(20+years),high‐resolution,quarterlysampledXBTtransectsenclosingtheTasmanSea(PX09;PX31;PX34:the“TasmanBox”)weresupplementedbyaltimetrydataandusedtoexaminechangesinthevolumetransportassociatedwiththeSouthPacificboundarycurrentsystem.OndecadaltimescalestheeastwardextensionoftheEastAustralianCurrent(EAC)–knownastheTasmanFront–wasfoundtobeanti‐correlatedwiththesouthwardEACextension,inresponsetobasinwidechangesinthewindstresscurl.Thisappearstobeassociatedwithastrengthening/shiftofthegyreratherthanachangeintheseparationlatitudeoftheEAC.KathyHillnotedthattherewouldbemooredarraydeployedalongPX31offBrisbanein2012(PIsRidgwayandSloyan,CSIRO)aspartofalong‐termmonitoringeffortoftheEAC.AnoverviewofXBTobservationsfromXBTtransectAX22,whichareusedtoinvestigatechangesintheAntarcticPolarFrontintheDrakePassagewaspresentedbyJanetSprintall.Annually,between6and8realizationsarecarriedoutontheR/VL.M.Gould,96realizationssince1996.XBTsaredropped6‐12kmapart,XCTDsoccasionallyaswell.SinceoceanfrontscoalesceintheDrakePassage,thisisconsideredtobeagoodareatostudyfrontalvariability,inwhichsmallseasonalvariabilityhasbeenobserved.Whentheseasonalcycleisremoved,thereremainsa50kmsouthwardshiftinthePolarFront.ObservedchangesinthelocationanddepthofthemixedlayeroftheAASWwerelinkedtoSAMandLaNinaindices.

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ResultsobtainedusingobservationsfromtheXBTtransectAX25werepresentedbyIsabelleAnsorge,whichrunsfromSouthAfricatoAntarctica.Thistransecthasbeenoccupiedsince2004,withrealizationscarriedoutmainlyduringthesummermonths,18totaltothedateoftheworkshop.TheseXBTobservationsareusedtohelpunderstandtheflowbetweentheIndianandAtlanticOcean,monitorAgulhasRings,andcapturethevariabilityofthevariousAntarcticCircumpolarCurrentfronts.ThistransectislinkedtotheFrench‐RussianregionalprojectsBONUS‐GOODHOPE.VolumetransportsintheareaarebeingestimatedusingacombinationofXBTmeasurementsandCTDobservations.However,itwasnotedthatmoreXBTandCTDmeasurementsarenecessary,particularlyduringthewintermonths,toimprovetheseestimates.Itwasagreedontakingadvantageofopportunitiestocarriedthemout.BesidesthecurrentXBTopportunitiesavailableduringtheDecember‐Februaryperiod,anewSouthAfricanresearchshipmaypresentaviableplatformforadditionaltransectsanddeployments.AstudyontheTropicalAtlanticVariabilityduring1993‐2010usingacombinationofXBTandaltimetryobservationswaspresentedbyMarlosGoes.“Synthetic”temperatureandsalinityprofilesweredevelopedtolinkthedynamicheightobtainedfromXBTobservationswiththealtimetricseasurfaceheight(SSH)andclimatologicalreferencelevels,allowingestimationofthesurfaceandsubsurfacecurrentssince1993.GoodagreementisfoundforthesynergistictransportestimatesofthesurfaceNorthEquatorialCounterCurrent(NECC),withweakeragreementfoundforthesubsurfaceNorthEquatorialUnderCurrent(NEUC)astheSSHsignalisdegraded.ResultsshowedthattheseasonalityoftheNECCiscloselyrelatedtothemeridionaldisplacementoftheITCZandstrengtheningoftheNorthBrazilCurrent,whiletheNEUCexhibitsbothannualandsemi‐annualvariability.IntheSouthEquatorialUnderCurrent,theXBTtransportestimatesshowmuchhighervariabilitycomparedtothetransportestimatesusingthesyntheticSSHprofiles.ResultsfromtheIndianOceanHDtransectIX01,whichwasimplementedin1980,presentedbySteveRintoulareneededtoseparatethenumerousmechanismsdrivinglow‐frequencyvariabilityintheocean.ThetransportestimatesfromIX01indicatethattheIndonesianThroughflowisdrivenbothbytheIndianOceanDipole(IOD)andENSOviadistinctphysicalmechanisms.Asaresult,someENSOandIODeventsinteractconstructivelywhileothersoppose.ResultsobtainedusingIX28observationsindicatethatthepolarfrontsseparateinfilamentswithverysmallspatialscalesandwithverticalstructurecanonlyberesolvedwithXBTobservationscollectedalongthesefixedtransects.Becausethesefeaturesaresosmall,otherobservingsystemswillbepronetoaliasing.

MeridionalHeatTransport

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HDXBTtransectshavebeenkeytoobtainamulti‐decadalrecordofmeridionalheattransport(MHT)at26°NintheNorthAtlantic.MollyBaringerpresentedresultsfromthistransect,showingthattheXBT‐derived15year‐longtimeseriesofMHTisinverselycorrelatedwiththeAMOindex,akeyclimaticindexoftheAtlanticbasin.ThisrelationshiphasbeenrecentlydetectedthankstothelengthoftheXBTrecordandwillbeusedtovalidatenumericalmodelingresults.TheMHTisalsobeingcomputedintheSouthAtlantic,andincombinationwithanaltimetrybasedmethodology.PreliminaryresultspresentedbyGustavoGonishowthatbetween20°Sand40°SaltimetrytogetherwithhydrographicobservationscouldbeusedasaproxytoestimatethevariabilityoftheMHTwithlatitude.Inaddition,satellitealtimetryobservationscanbealsousedtoextendbackintimeto1993therecordofMHT.UpperOceanHeatContentTherecentGHRSSTmeetingasitrelatestoXBTswasreportedbyHelenBeggs.GHRSSTistheglobalhigh‐resolutionseasurfacetemperaturegroup.ThemainusethatthisgrouphasforXBTsisasanindependentvalidationofSST,althoughpresentlyonlytheRSMAScomponentofGHRSSTusesXBTdataforvalidation.ThemainissueforGHRSSTtouseXBTdataistheresponsetime,asthefirst3metersoftheXBTdropareusuallynotusableduetostart‐uptransientsandnear‐surfacetemperaturespikes.However,itwasreportedthattemperaturevaluesatdeeperdepthscouldstillbeusedforvalidation.RequirementsforXBTsforvalidation:5minutestimeaccuracy,0.005degreesaccuracyinposition,0.01metersresolutionwith0.5metersaccuracyindepth,and0.05degreeaccuracyintemperature.Ingeneral,thesevaluesindicatethatXBTscouldbewidelyusedforGHRSSTvalidationpurposes.[PleaseseeHelenspresentationtodoublecheckrequirements.]AnovelmethodologythatusesEOFstocorrectsystematicerrorsinXBTprofiles.waspresentedbyMathieuHammond.Thismethodologyisbasedonremovingthedecadalvariationsthatcapturestheshorttermcoolingproducedbyvolcaniceruptions.TheglobaltrendsobtainedwereconsistentwithWCRPCMIP3trends.ResultspresentedshowsthatXBTsmayneedaseparatecorrectioninthewesternPacific,theareaiswheremostoftheXBTsaremanufacturedbyTSK.ThekeyrolebeingplayedbytheXBTnetworkinGODAEOceanView,thenewframeworkforoceanassimilationandforecastingoriginatedafterthecompletionofGODAE,waspresentedbyPeterOke.GODAEOceanViewaimstosupporttheobservationalcommunitywithfeedbackontheimpactofobservationsinforecastskill.Resultsfromthisprojectshowthatnotassimilatingin‐situobservationscandegradeseasonalpredictionsby25%.Whilesatellitealtimetryhasbeenidentifiedasthemostimportantcomponenttoadequatelyforecastthe(short‐range)evolutionofmesoscaleeddies,XBTobservationsstillremainasoneofthecoredatasetforshort‐rangeforecasting.

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You‐SoonChangpresentedastudyofOHCdecadalchangesandtrendsestimatedwiththeGFDLoceandataassimilation(ODA)system,whichassimilateshistoricalXBTobservations.VariousmechanismsthathavebeensuggestedtogeneratePacificDecadalVariability(PDV),suchasair‐seainteractionintheNorthPacific,tropical‐extratropicalteleconnections,internaltropicaldynamics(e.g.ENSO),andrectificationofENSO.P.DiNezioexaminedvariousclimatemodelsandsuggestedthatthePDVisassociatedwithaweaklycoupledmodethatgeneratesdecadalENSO‐likeSSTvariabilityviachangesintheWalkerCirculationthatareamplifiedbyoceansurfaceprocessesonly,i.e.withoutparticipationbytheequatorialthermocline.PacificOceanXBTandCTDdata(1970‐2010)wereusedtoevaluatethistheory.ThermoclinedevelopmentwasidentifiedwheremaximumdT/dzoccursineachprofileandlinkedtowindandSSTvariability.ThedatasupportedtheclimatemodelsandsuggestedthatunlikeduringENSOevents,onPDVtimescaleswarmerSSTisassociatedwithashallowerthermoclinedrivenbyweakertradewinds.TheU.S.Navy’sGlobalOceanTemperatureandSalinityClimatologybyRobertHelber.TheUSNavydevelopsamonthly,globaloceantemperatureandsalinityclimatologyat78depthlevelsto6600monaglobal1/4degreegrid,usingallavailableinsituprofiledata(e.g.Xbts,Argo,CTDsetc).Aftercheckingforoutliers,1.7millionXBTsareincludedinthefinaldataset(uptoJuly2008).Improvementstotheclimatologyfocusonachievingaccuracyintheverticalgradientoftemperature,particularlynearthecoastorinregionsofslopingbathymetry,asthisquantityhasimportantapplicationsinNavyacoustics.TheeffectofdifferentXBTfall‐ratecorrectionsonoceanheatcontentcalculationswaspresentedbyTimBoyer.XBTdatacoveralargeproportionoftheoceanbetween1967and2000’s.In2009,XBTsstillrepresentalargefractionofthecurrentprofiledata:6%to9%oftheglobaldatabaseareXBTsandhenceitisvitaltocorrectXBTdataasbestaspossible.Dr.Boyershowedtheglobalheatcontentestimatesusingthecurrentlyavailablefall‐rateXBTcorrectionschemes.HeappliedXBTcorrectionstothesamedatasetWODthatincludedtheLevituscorrection(whichcontainsnoregardtoXBTbehaviour),Wijffelsetal(2008;whichisapuredepthcorrection)Ishii&Kimoto(2009),Gouretski&Reseghetti(2010;adepth,temperatureandthermalbiascorrection),Good(2011:whogeneratedadepthcorrectionbasedonprofilesthathittheseafloor),andDeNezioandGoni(2010;whichusedconcurrentXBTandArgodatatoestimatecorrection).Ingeneral,thereremainsalargespreadinheatcontentvaluesusingdifferentcorrections.However,allcorrectionsremovethelargeheatcontentincreaseseeninthe1970‐1980’s.NocorrectionsappeartoworkwillinthenorthernIndianOcean.Gieseetal(2007)appliedtheW08andLevituscorrectionintheSODAmodeland

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showedthatthecorrectionsimprovemodelperformance.Lymanetal(2010)performedasimilaranalysisandfoundsimilarcomparisons.AnewapproachtoestimatingXBTerrorswaspresentedbyRebeccaCowley.InthispresentationalargedatabaseofXBTsandCTDswasusedforanalysisthatresultedin5000CTD/XBTcolocatedpairs.ThefinescaletemperaturestructureineachprofileisusedtomatcheachXBTtothecollocatedCTDateachdepthbycomputingthemaximumcorrelationateachdepth,thenfittingthedepth“corrections”toaline(withslopeandoffset).Whatremainsafterthisdepthcorrectionistermedthethermalbias.TheanalysisisdoneseparatelyforeachprobetypeandalldataisinitiallycorrectedtotheHanawafall‐rate.Ingeneral,thestudyshowedthatthedepthoffsetisconstantovertimeandisaround1.2mfordeptherror.Thethermalbiasvariesovertimeandislargerbefore1990,probablybecauseofearlyanalogsystemsandlargeractualbias.Highresolution,deepprobesoffsetisabout0.4˚C.Thethermalbiasisdepthindependentandlargelyresponsibleforthethermalhumpinthe1970s.Removingthatfirstleavesessentiallynosignificantfallratechangeovertime(expectperhapsasmallslowingofthefallratewithtimesincethemid‐1990s).ThisstudyfoundnoclearrelationshipbetweenTemperatureandfallrate(e.g.therallratedoesnotseemtobedifferentincolderverseswarmerwatersassomestudieshavesuggested).Thestudyrecommendsaminimumof30highresolutionpairsandminimumof50lowresolutionpairstogetrobustestimate.Anothernewanalysisonfall‐ratecoefficientswasdescribedbyLijingChengthatusesahistoricalXBTdatabasedofside‐by‐sideprofilestoestimatethedepthwithDepth=at2+bt+c,whereaandbarethetypicalfallratecoefficientspreviouslyestimatedandcisan“offset”termasdescribedbyBoyerandothers.Heshowedthatusinganintegratedmethodtocalculatea,bandoffsetfromthatpairsdatabaseandusingthoseestimatestocorrectthedepthandthermalbiasgenerallyimprovedata.Thisstudyshowsaclearrelationshipbetweenlatitudeandthecoefficientaandsuggestthatthe1970‐1980heatcontent“hump”couldbecausedbygeographicaliasingofthedata.Furtherthissuggeststhatwecouldbeovercorrectingthe1970‐1980warmperiodbyusingXBTbuddiesthathaveoccurredlargelyinthetropicalregion.Thisanalysisshowedapronouncedshiftinthefall‐ratein199,whichisanecdotallylinkedtoimprovedwirecoatingtechniquesappliedbythemanufacturer.Italsoshowedalinearlycorrelatedrelationshipbetweenaandtheoffset.Inanefforttounderstandthepossiblephysicalmechanismsthatcouldreasonablyadjustthefall‐arteofXBTs,KimioHanawapresentedresultswheretheweightoftheXBTwassystematicallyalteredtocheckthefall‐ratecharacteristics.Inordertoaccomplishthisexperimentandassessthedependenceoftemperature,weightofprobeandamountofwire,anumericalmodelofprobedescentwasdevelopedandevaluatedusingseveralprobetypes(TSKandSippican)comparedtoCTDprofiles.AssumingafallratemodellikeAt^2+Bt,theAcoefficienttranslatesintosomethinglikeinitialspeedastheprobehitsthewaterandtheBcoefficienttranslatesintoreductioninmasswithtimeasthewirespoolsoff.Thisexperimentshowedthat

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coldertemperatureprobesfallfasterthaninwarmwater(similartoresultsofKizu2011).HeavyprobesasexpectedfallfasterthanLighterprobes.TSKprobesfallfasterthanSippicanprobes(allotherconditionsremainingthesame).Thefallrateaccelerationcoefficientaincreasesby0.06forevery10gofweightincrease.Interestingly,theobservedfallratechangesdonotmatchthenumericalexperiments,whereweightwasasecondaryfactortoprobeshape.Theoverallrecommendationsarethatprobeshapeandweightshouldbemaintainedasmuchaspossible.TheseexperimentsareexpectedtobecontinuedannualtoevaluatetheXBTprobesthroughtimeandchecktheperformanceofthenumericalmodel.TheexperimentdescribedabovewaspossiblethroughthecarefulproceduresoutlinedbyShoichiKizu.Toreducetheweightofaprobe,theinsideofthenoseconeisscrapedout,eliminating10to20ginthecone.SippicanprobesarelighterthanTSKprobesbyabout12gduealmostentirelytothedifferencesintheweightofthewires.Thewiregaugeisthesameandthedifferenceisthecoating.ThedifferentstructuresandmassbalanceoftheLMSandSippicanprobesresultsinrelativelysimilarfallrates.LargelyduetothedecreasedweightoftheSippicanprobes,experimentsdemonstratethattheSippicanfallsslowerthantheHanawa1995fallratebyabout2%andtheTSKprobesfallabout2%fasterthantheHananwa1995fallrate.ReducingtheweightoftheTSKprobessothattheymatchtheSippicanweightstheSippicanstillhasaslowerfallrateduetothestructuraldifferences.EvenreducingtheweightoftheTSKby20gresultsintheSippicanprobestillfallingslowerthanthelighterTSK(‐20g).Thelossofwiredoesnotslowtheprobesdownproportionally.Dragofwaterprobablyaffectsthefinalfallrate,suchasareductionintheprobewobblewithtimecouldreducethedragcounteractingtheimpactofreducedweight.Sippicanshowslargetemperaturebiasatdepthinsomeprobeswithnocharacteristicchangesinprofileshapetoindicateaproblem.Thisishypothesizedtobeanunspecifiedwireproblem.Ingeneralweighttolerancesof+/‐1g(Sippican)and+/‐5g(TSK)isgoodenoughtocontrolfallrateto1%.DiscussionsensuredaboutseveralchangestotheXBTprobedesignthatcouldpossiblyimpactthefallrate.Theseincludechangesinthecontactpinmaterial,thecontactgapsizebetweennoseandtail,thewirenetting,thewirecoatingandalsoachangeinthelocationofthemanufacturingfactory.ThehistoricalXBTdatabasecomprisesalargefractionofthetimehistoryofsubsurfacetemperataures.AreviewofsomeoftheissuesassociatedgeneratingwithheatcontenttimeseriesestimatesantheimpactoftheXBTfallrateissuewasdiscussedbyCatiaDomingues.XBTdataisclearlyimportanttoclimatestudiesas90%oftheheatcontentistrappedintheoceanandthermalexpansioncontributestosealevelrise.Ingeneral,theXBTdatawasnotdesignedforclimatestudies,buttheyareusedinthiswayanyway.Qualitycontrolandrescueofmetadataisimportant.Aprioritymustbemadeoftherescuefullresolutionversiondatafromthehistoricalrecords.Thispresentationshowedthatmappingissuesalonecanchangeheatcontentevenwithdifferentfallratecorrectionsappliedtothehistoricaldata(i.e.mappingseemstomakemoreofadifferencethantheactualfall‐ratecorrectionused).UsingtheENACTdataarchivechangedfairlydramaticallytheheat

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contentvariabilitybetweenabout1998toabout2002.Inparticular,theLyman(REF)methodtriestofillthegapsusingsatellitealtimetryandPeterGleckeretal.(REF)usemodelstogetapoolednoisetodeterminethesignal(fingerprint),othgivesubstantiallydifferentresultsusingthesameunderlyingdata.Oceantemperatureanomaliescanalsopartlybeexplainedbythenumberofprofilesavailableatanygiventimeandlocation.DifferentXBTbiascorrectionsgiveasimilarresult.

GeneralDiscussions

FundingandResearchv.OperationsWiththecurrentemphasisoftheXBTnetworkinHDsampling,thetransitionoftheXBTnetworkfromresearchtooperationalmodewasdiscussed.InAustralia,anoperationalnetworkcouldprobablysecurefunding.Ontheotherhand,itwasmentionedthattransectsfundedbytheUSNSFrespondtoascientificjustificationandnottomonitoringefforts,thereforetheneedtoremaintheminresearchmode.Manyoftheglobaltransectsarestillconsideredtooperateinresearchmode,sincetheirspatialandtemporalsamplingarestillbeingassessedandallXBTdataqualitycontrolisdoneatresearchfacilities.ItwasarguedthatthescientificqualitycontrolthatisappliedtoallXBTcouldalsodegradeifthemaintenanceofthenetworkisconvertedintooperational.ItwasagreedthatperhapsitwouldbebesttodescribetheoperationsoftheXBTnetworkasbeinginsustainedmode.Itwassuggestedtoobtainendorsementfromaninternationalagency,suchasCLIVAR,tofacilitatesecuringfundingofthenetwork.However,CLIVARhasnotendorsedanyotherplatform,suchasArgoorsurfacedrifters,butonlyscientificprograms.Itwasagreedthatfundingwouldcontinueiftheargumentstosustaintheobservationswerecompelling.However,differentagenciesarecompelledbydifferentarguments.Forexample,whiletheUSNSFseeksnewscience,NOAAsupportstheoceanobservingsystemforlongtermmonitoring.Lackoffundinghasalreadycausedtheterminationofglobalfrequentlyrepeatedtransects.Forexample,inregions,suchastheNorthPacificHFtransectsweretheonlyXBTrepeatedtransectsinplace.InthePacificOcean,transectsPX04/05thatarecarriedbyIRD/Noumeaareatriskofbeingdiscontinued.Itwasnotedthatgivenitsimportance,itmightbepossibleforNOAAtohelpsupportthistransect,providedthatthedataaremadepubliclyavailableinnear‐realtime.IntheSouthIndianOcean,HDtransectsmaybealsoatriskofbeingdiscontinuedduetolackoffunding.

Logisticsandimplementation

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TheShipofOpportunity(SOOP)ImplementationPanel(SOOPIP)overseesseveralaspectsofthelogistics,implementation,andmaintenanceoftheXBTnetwork.AsummaryofSOOPIPactivitiesandtheirlinktotheXBTnetworkwasgivenbyGustavoGoni.TheSOOPisacomponentoftheGlobalOceanObservingSystemcoordinatedbyJCOMM.TogetherwiththeVolunteerObservingShips(VOS)meteorologicalobservationnetworktheyformtheShipofOpportunityTeam(SOT).SOOPactivitiesincludetherecruitmentofshipsandriders,softwaredevelopment,collaborationtoprovideprobes,real‐timeanddelayed‐modedataqualitycontrol,anddatadistribution.ThemaintenanceoftheXBTnetworkanddistributionofthedatatoresearchersarealsoprioritiesoftheSOOP.InadditiontotheXBTnetworktherearesmallercomponentsofSOOP,suchasthermosalinograph(TSG)observations.Theconstantchangeofroutes,partlybecausetoadapttoworldcommercialtrade,hasalwaysbeenanissueinthedeploymentofXBTs,surfacedrifters,andArgoprofilingfloats.However,therecruitingofshipsthattransectalongfixedroutescarriedoutatleast4timesperyearconstitutesanadditionaldifficultytotheoperations.Inparticular,thesespecifictransectswerediscussed:• ItwasnotedthatthetransectPX50,whichgoesfromNewZealandtoChilehasessentiallynotcommercialtransit.ApartialtransectfromChiletoEasterIslandwasproposedinordertoatleastmonitortheeasternboundarycurrent.

• HDXBTtransectAX18,whichgoesfromCapeTowntoBuenosAires/Montevideo,hasbeendifficulttomaintainbecausemostshiproutescurrentlygofromCapeTowntoSantos(Brazil)at24°SandnottoBuenosAiresat34°S.

• Somelogisticalissueswerecloselyrelatedtofundingissues.Forexample,transectPX04/05needsaship‐riderandacontinuousinstallationmostlyoneachrealizationwiththevesselchangeseveryfewyearsnecessitatingtheXBTsystembereinstalled.Atpresent,nodataisenteredintheGTSbutaretransmittedtoCoriolis.

OnclimatequalityXBTdataThispresentationandthediscussionthatfollowedpointedtoseveralrecommendations:

1. ScientificcommunityneedsrecommendationsforXBTcorrections.2. Correcteddataneedstobemadeavailable.Notethatlongtermdatasets

mustbeclearlyidentifiedifcorrectionshavebeenapplied(e.g.WODstandardleveldatahasXBTcorrectionapplies,butobservedleveldatahasnocorrections).

3. Thereshouldbeawebsitewithliteratureandfall‐ratecomparisondata(NODCXBTbiaspageisagoodstart).

4. Implementyearly,globalfall‐ratecomparisonstests(toaugmentNavalPostgraduateSchoolannualtestingsince1999).

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5. Developanddocumentcriteriaforperformancethatcanassessedannually.

6. Publishasummarywhitepaperwithrecommendationsformovingforwardthatalsoclearlydescribeseachmethodsothatuserscaneasilychosethemethodmostappropriateforthem.

XBTScienceSteeringTeam OneoutcomeoftheworkshopwastheestablishmentofanXBTScienceSteeringTeam(XBTSST).ThefocusofthisTeamshouldbetoinformtheoceanographiccommunityonthebenefitsofXBTtransectdataformonitoringmassandheattransportsinboundarycurrents,andstudiesofeddyandfrontalvariability,withthefollowinggoals:

1) Haveavoiceinthecommunitytocommunicatescientificresults.MuchofthisdiscussionwasfocusedondevelopingaparallelmodeltothatoftheArgocommunitywhohavebeeneffectiveininvolvingthebroaderoceanographiccommunityintheutilityofArgodata,andthereforemoresupportiveofthecontinuanceoftheArgoprogram

2) GathertheXBTcommunitytodiscussscientificadvancesintheuseofXBTobservations;

3) Helptoenhanceinternationalscientificcollaboration;4) MakerecommendationsandprioritizetransectsontheXBTnetwork;5) Makerecommendationsondatamanagement;6) Createlinkswithotheractive/recognizedscientificandoperationalpanels;

and7) MusthavesomecontrolovertheactivitiescarriedoutbytheShipOf

OpportunityProgrammeImplementationPanelinordertobeeffective.ThetermsofreferenceoftheXBTSSTweredraftedandpresentedforreviewandcomments:

1) TheXBTSSTwilloverseethedevelopmentoftheglobalXBTnetworkwiththeprimaryobjectiveofobtainingprofilesoftemperature;

2) TheXBTSSTwilldefinethescopeoftheXBTnetworkwithrespecttothedesignandgeographicalextentofthenetworkandtheobjectivesofdatamanagement;

3) TheXBTSSTwillprovideadviceonthecontents,quality,andtimelinessoftheXBTdatastreamtoensurescientificandoperationalrequirementsaremet;

4) TheXBTSSTwillencourageobservingsystemexperimentsandstudiestoguidethelong‐termdevelopmentoftheXBTsamplingdesignandtocomplementthescientificjustificationofthetransectsalreadyinplace;

5) TheXBTSSTwillprovideadviceandguidancerelatingtotechnicalinnovationsrelevanttotheXBToperationsandnetwork;

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6) TheXBTSSTwillliaisewithrelatedglobalobservingsystems,includingthoseconcernedwithsatelliteobservationsandwithglobalscaleship‐basedhydrography,inparticularGOOSandGCOS,throughtheiroversightandcoordinationbodies,OOPC,GSSC,GCOSSC,JCOMM/OCG(includingJCOMMOPS);

7) TheXBTSSTwillprovidescientificguidanceto,andreceiveadvicefrom,therelevantscientificpanels(e.g.CLIVAR)andworkinggroups;

8) TheXBTSSTwillassistnationalandregionalprogramstohelpensuresustainedfundingfortheoperationoftheXBTnetwork;and

9) TheXBTSSTwillmaintainfluidcommunicationswithandproviderecommendationstoJCOMMSOTandSOOPIPwithreferencetonetworkimplementationanddatamanagement.

Thefollowingacceptedorwerenominated(*)aspotentialmembersofthefirstXBTSST.ThefinalmembershipofthefirstXBTSSTwillbemadepubliclyavailableduring2012.

JanetSprintall(UAA,SIO,co‐chairforscience)AnneThresher(Australia,CSIRO,co‐chairfordatamanagement)GustavoGoni(USA,NOAA,co‐chairforoperations)DeanRoemmich(USA,SIO)MollyBaringer(USA,NOAA)GillesReverdin(France,U.Paris)GopalakrishnaVisa(India,NIO)MauricioMata(Brazil,FURG)SebastiaanSwart(SouthAfrica,UCT)RebeccaCowley(Australia,CSIRO)SoichiKizu(Japan)RobertHelberg(USA,USNavy)AlexanderGanachaud(Noumea,IRD)TimBoyer(USA,NOAA)CharlesSun(USA,NOAA)LoicPetitdelaVilleon(France,IRD)BirgitKlein(Germany,*)CandyceClark(ex‐officio,USA,*)AlbertoPiola(Argentina,*)PeterOke(Australia,*)HellenBeggs(Australia,*)*nominated,pendingacceptance.

ThefutureofXBTtransectsDiscussionswereheldinwhichthefuturedirectionofXBTobservationswerepresented.ThenetworkhassuccessfullytransitionedintotheHighDensitymodeofsamplingmakingavailableuniqueobservationswithemphasisinmonitoring

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currentsandmeridionalheattransport,whichcannotbeaccomplishedusingdatafromotherobservationalplatform.XBTtransectswillkeepprovidinguniqueandcriticalsamplingoftemperaturesectionsalongrepeatedtransects,manyofwhichhavebeencarriedoutforlongerthan15years.ThestrengthofthenetworkalsoliesinthatcomplementaryobservationscanbeobtainedsimultaneouslyduringXBTdeployments.Inaddition,itwasdiscussedhowtheobservingsystemwouldlooklikeinapproximately10yearsunderdifferentscenarios,onewithXBTdata;whereXBTscontinuebeingthebackboneoftheboundaryobservingsystem;andanotherwithoutXBT;wheregliderstookoverobservingtheboundaries.Itwasagreedthatthisscenariomaynotoccursoonbecausea)lackofinvestmentindevelopinganappropriateplatform,andb)gliderscannotyetswimagainstmostoceanscurrentsmaking,therefore,theirusenotappropriatetomonitorstrongboundarycurrents.Technologydevelopmentwasalsodiscussed,includingimprovingautolauncherstothebuildingofanXBTprototypewithpressureswitchesandmoreaccuratetemperaturesensors.GustavoGoninotedthatSipppicanvolunteeredtotaketheleadinthedesignoftheprototypewithAOMLcollaboratingduringthetestingphase.

ActionItemsSummaryInsummary,thegroupagreed:

1. ToestablishanXBTScienceTeam(XST)tomakerecommendationsontheimplementation,maintenance,andenhancementoftheXBTnetworkanddatamanagementpractices,relyingthereforeonasingleoverseeingbodytomakerecommendationsandtosetuppriorities.

2. ThattheXSTneedstobewellcoordinatedwithotheroperationalgroupssuchasOOPC,SOOPIP,etc.

3. Co‐chairswerenominated(JanetSprintal,GustavoGoniandAnnThresher)totheXSTandnumerousmemberssuggestedincludingShoichiKizu,TimBoyer,RebeccaCowley,Gopal,RobertHelber.

4. AdrafttermsofreferencewasapprovedfortheXSTandwillbecirculatedtootherinterestedparties.

5. ThereshouldbeaScienceWorkshoporScienceTeammeetinghostedapproximatelyeverytwoyearsperhapslinkedtoSOOPIPorArgosciencemeetings.TheformatshouldconsiderXBTbiases(1day)andscientificadvances(2days).

6. AproposaltoSCOR(IOC)shouldbepursuedtoconstituteascienceadvisorypaneltodraftrecommendationsforthesciencecommunityonfallratecorrections.

7. AplanfordistributingcorrectedXBTdatatothescienceandmodelingcommunityshouldbedrafted.

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8. AsciencepaperontheuniqueutilityofXBTstocaptureboundarycurrenttransportsandothermajoroceancurrentsshouldbecompleted.

9. CreateandmaintainadedicatedwebpagewithinformationabouttheXBTSteeringTeam,andwithproductsonoceancurrentsandmeridionalheattransport,distributionofqualitycontroldata(e.g.withlinkstodatadistributioncenters).ThewebpageshouldalsoclearlydescriberecommendationsforXBTdatacorrections,meetingsandlinkstovariousXBTsites.

10. TheendorsementofCLIVARshouldbesought.11. AworkshopsummaryshouldbesubmittedtoEOS.12. V.V. Gopalakrishna offered to host the next XBT science meeting in India. 13. TasktheScienceTeamtoassesstheimportancetocarryouttransectson

marginalseas(Mediterranean,GulfofMexico)thatcouldbecriticalbecauseoflackofothertypeofsustainedhydrographicobservations.

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WorkshopAgendaXBTScienceWorkshopMeetingAgenda7July­8July2011Day1:Thursday7July2011

Start End Time Item Speaker AffiliationTimeKeeper Rapporteur

9:00AM

9:05AM 0:05 Introductions

MollyBaringer NOAA

9:05AM

9:10AM 0:05 Welcome/Logistics GraemeBall ABOM

9:10AM

9:25AM 0:15

TheXBTNetworkOverviewofProgramObjectives GustavoGoni NOAA

9:25AM

9:40AM 0:15

UseandrequirementsforXBTsurfacetemperatureobservationsbytheGroupforHighResolutionSST(GHRSST) HelenBeggs ABOM

9:40AM

10:40AM 1:00

OceanCirculationandtheMass,Heat,andFreshwaterBudgetsofLargeOceanRegions:TheSynergiesofHighResolutionXBTTransects,Argo,andSatelliteAltimetry

DeanRoemmich Scripps

10:40AM

11:00AM 0:20 BREAK

11:00AM

11:30AM 0:30

RecentScienceHighlightsusingAir‐SeaUnderwayObservationsinDrakePassage JanetSprintall Scripps

11:30AM

12:00PM 0:30

UnderstandingtheACCsouthofAfrica

IsabelleAnsorge UCT

MollyBaringer

TimBoyer

12:00PM

1:00PM 1:00 LUNCH

1:00PM

1:30PM

0:30 OntheHighDensityXBTlines

SteveRintoul CSIRO

LisaKrumme

l PedroDiN

ezio

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inAustralia

1:30PM

2:00PM 0:30

EstimatingtheMeridionalHeatTransportandOverturningCirculationfromXBTs

MollyBaringer NOAA

2:00PM

2:30PM 0:30

VariabilityoftheMeridionalHeatTransportandOverturningCirculationintheSouthAtlantic GustavoGoni NOAA

2:30PM

3:00PM 0:30

EmpiricalcorrectionofXBTdataandglobalfieldreconstructionusingEOFs

MathieuHamon Ifremer

3:00PM

3:20PM 0:20 BREAK

3:20PM

4:20PM 1:00

ObservingSystemEvaluationactivitiesunderGODAEOceanView PeterOke CSIRO

4:20PM

4:50PM 0:30

Basinpatternsoftheupperoceanwarmingfor1993‐2008

You‐SoonChang NOAA

4:50PM

5:20PM 0:30

InterannualandintraseasonalvariabilityofupperlayertemperaturefieldsinthesoutheasternArabianSea

VissV.Gopalakrishna NIO

5:20PM

5:50PM 0:30

DISCUSSION‐SustainingtheObservingSystem

AlexGanachaud IRD

6:00PM

RECEPTION‐SummitCafé(700CollinsStreet)

XBTScienceWorkshopMeetingAgenda7July­8July2011

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Day2:Friday8July2011

Start End Time Item Speaker AffiliationTimeKeeper Rapporteur

9:00AM

9:30AM 0:30

ObservationalEvidenceforaWeaklyCoupledModeofPacificDecadalVariability

PedroDiNezio

NOAACIMAS

9:30AM

10:00AM 0:30

Monitoringthenorthernlimbofthesubtropicalgyrewithhigh‐resolutionXBTsurveysintheSouthPacificOcean

AlexGanachaud IRD

10:00AM

10:30AM 0:30

DecadalChangesintheEastAustralianCurrentsystem–therelationshiptochangesintheSouthPacificGyre KatyHill IMOS

10:30AM

10:50AM 0:20 BREAK

10:50AM

11:20AM 0:30

TheU.S.Navy’sGlobalOceanTemperatureandSalinityClimatology

RobertHelber NRLSSC

11:20AM

11:50AM 0:30

InvestigationoftheTropicalAtlanticVariabilityduring1993‐2010

MarlosGoes

NOAACIMAS

GraemeBall

JanetSprintall

11:50AM

12:20PM 0:30

DISCUSSION‐Thewayforward

GustavoGoni NOAA

12:20PM

1:20PM 1:00 LUNCH

1:20PM

1:50PM 0:30

EffectsofdifferentXBTcorrectionsonhistoricandrecentoceanheatcontentcalculations TimBoyer NOAA

AnnThresher

RebeccaCowley

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1:50PM

2:20PM 0:30

Anewanalysisonfall‐ratecoefficientsinhistoricalXBTdatabasedonside‐by‐sidecomparisons

LijiongCheng IAP

2:20PM

2:50PM 0:30

ANewViewofXBTBiases

RebeccaCowley CSIRO

2:50PM

3:10PM 0:20 BREAK

3:10PM

3:40PM 0:30

TrialtocheckXBTfallrateandtodevelopsimplenumericalmodel

KimioHanawa TU

3:40PM

4:10PM 0:30

Anassessmentoftheeffectofvarianceinprobeweightonthefall‐rateofexpendablebathythermographandpuretemperaturebias

ShoichiKizu TU

4:10PM

4:40PM 0:30

DetectionandAttributionofUpperOceanWarming

CatiaDomingues ACECRC

4:40PM

5:10PM 0:30

DISCUSSION‐WrapUp

MollyBaringer NOAA

Abreviation InstitutionNOAA NationalOceanicandAtmosphericAdministrationABOM AustralianBureauofMeteorology

ScrippsScrippsInstitutionofOceanography,UniversityofCaliforniaSanDiego

UCT UniversityofCapeTown,SouthAfrica

CSIROCommonwealthScientificandIndustrialResearchOrganisation

NIO NationalInstituteofOceanography,India

CIMASCooperativeInstituteforMarineandAtmosphericStudiesUniversityofMiami,Miami,Fl

IRD InstitutdeRecherchepourleDéveloppementIMOS IntegratedMarineObservingSystem,UniversityofTasmaniaIAP/AC InstituteofAtmosphericPhysics,ChineseAcademyof

24

SciencesNRL NavalResearchLaboratory,StennisSpaceCenterTU TohokuUniversity

ListofParticipantsIsabelle Ansorge Senior Lecturer Oceanography Dept. University of Cape Town South Africa Tel 27 + 21 6503280 isabelle.ansorge@uct.ac.za Graeme Ball Manager, Marine Operations Group, Australian Bureau of Meteorology 700 Collins Street, Docklands, Victoria 3008, Australia GPO Box 1289 Melbourne, Victoria 3001, Australia Tel +61 3 9669 4203 Fax +61 3 9669 4168 g.ball@bom.gov.au | Molly Baringer NOAA/AOML 4301 Rickenbacker Causeway Miami, Fl 33149 Tel (305) 361 4345 Molly.Baringer@noaa.gov Helen M. Beggs Centre for Australian Weather and Climate Research, Bureau of Meteorology, Tel:[+61 3] 9669 4394; Fax [+61 3] 9669 4660 CAWCR, Bureau of Meteorology, GPO Box 1289, Melbourne, Vic 3001 AUSTRALIA H.Beggs@bom.gov.au Roger Bodman, Unimelb, Australia

The University of Melbourne, Parkville, Victoria 3010 School of Earth Sciences, Rm 317, McCoy Building, Cnr Swanston and Elgin Sts. H9783 6601 M0433 963 322 rwbodman@unimelb.edu.au Tim Boyer NationalOceanographicDataCenter1315East‐WestHighwaySilveSpring,MD20910US301‐713‐3290x186Tim.Boyer@noaa.gov Gary Brassington BOM, Australia g.brassington@bom.gov.au Jaclyn Brown Centre for Australian Weather and Climate Research (CAWCR) GPO Box 1538, Hobart, Tas. 7001 Australia Ph.+61 3 6232 5113 Mob. 0438 077 444 jaclyn.brown@csiro.au Wenju Cai CSIRO Marine & Atmospheric Research, Aspendale, Victoria Tel: + 613 9239 4419 Wenju.Cai@csiro.au You-Soon Chang GFDL/NOAA,PrincetonUniversity

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UniversityForrestalCampus,201ForrestalRd.,Princeton,NJ08540You‐Soon.Chang@noaa.gov Lijing Cheng Institute Of Atmospheric Physics, Chinese Academy Of Sciences, Beijing Qi Jia Huo Zi, De Sheng Men Wai Street, Institute Of Atmospheric Physics, BEIJING 100029 Tel 86-10-82995291 chenglij@mail.iap.ac.cn Philip Chu Naval Research Laboratory OceanDynamicsandPredictionBranchOceanographyDivision(Code7322)NavalResearchLaboratoryStennisSpaceCenter,MS39529(228)688‐4507 chu@nrlssc.navy.mil Rebecca Cowley OceanDataAnalyst/ScientificProgrammerCentreforAustralianWeatherandClimateResearch(CAWCR)CastrayEsplanade,BatteryPointTasmania,Australia,7000Tel:+61362325446Fax:+61362325123Rebecca.Cowley@csiro.au Peter Dexter Co-President of JCOMM International Oceans Policy Advisor, Bureau of Meteorology GPO Box 1289, Melbourne, Vic, 3001 Australia Tel: +613 9669 4870 Fax: +613 9669 4275; M: +61 417 353 459 p.dexter@bom.gov.au Pedro DiNezio UM/CIMAS, NOAA/AOML, US

4301 Rickenbacker Causeway Miami, Fl 33149 Pedro.DiNezio@noaa.gov Catia Motta Domingues ACE CRC, Hobart, Tasmania, Australia CSIRO Marine and Atmospheric Research, Private Box 1, Aspendale VIC, 3195, Australia Tel: +61 3 9239 4411 Catia.Domingues@csiro.au Alexandre Ganachaud InstitutdeRecherchepourleDéveloppementBPA5Noumea98848NewCaledonia+687260812Alexandre.Ganachaud@ird.fr Marlos Goes UM/CIMAS, NOAA/AOML, US 4301 Rickenbacker Causeway Miami, Fl 33149 Marlos.Goes@noaa.gov Gustavo Goni NOAA/AOML, US 4301 Rickenbacker Causeway Miami, Fl 33149 gustavo.goni@noaa.gov Max Gonzalez BOM, Australia Maxwell.gonzalez@bom.gov.au V.V. Gopalakrishna Physical Oceanography Division National Institute of Oceanography Donapaula, GAO -403004, INDIA 00-91-832-2450302 (Office) gopal@nio.org (E-mail) MathieuHamonIFREMER,France

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mathieu.hamon@ifremer.frProf. Kimio Hanawa Department of Geophysics, Tohoku University 6-3 Aramaki-aza-Aoba, Aoba, Sendai 980-8578, JAPAN Tel 81-22-795-6526 hanawa@pol.gp.tohoku.ac.jp Robert W. Helber Naval Research Laboratory Ocean Dynamics and Prediction Stennis Space Center, MS 39529 Tel: (228)688-5430 Fax:(228)688-4759 robert.helber@nrlssc.navy.mil Katy Hill IntegratedMarineObservingSystemUniversityofTasmaniaPrivateBag110Tel:+61405570686 katy.hill@imos.org.au Xinmei Huang Oceanographic Systems Development National Meteorological and Oceanographic Centre Bureau of Meteorology Australia X.Huang@bom.gov.au Shoichi Kizu Physical Oceanography Laboratory Department of Geophysics Graduate School of Science Tohoku University, Japan 6‐3AzaAoba,Aramaki,Aoba‐ku,Sendai,JapanTel: +81‐22‐795‐6528 kizu@pol.gp.tohoku.ac.jp Lisa Krummel MarineOperationsGroupBureauofMeteorology,Box1289,Melbourne,Victoria3001Australia

Tel:+61396694155L.Krummel@bom.gov.au Hans Ngodock Naval Research Lab Bldg 1009, Stennis Space Center, Mississippi Tel +1 228 688 5455 Hans.Ngodock@nrlssc.navy.mil Peter Oke CSIRO Marine and Atmospheric Research GPO Box 1538, Hobart TAS 7001 Tel: +61-3-6232-5387 Fax: +61-3-6232-5123 Peter.Oke@csiro.au GregReedHydrographyandMetocBranchRoyalAustralianNavyWyldeStreetPottsPointNSW2011Australiagreg@metoc.gov.auSteve Rintoul CSIRO, Australia steve.rintoul@csiro.au Dean Roemmich Scripps Institution of Oceanography UCSD 9500 Gilman Drive, La Jolla, CA 92093-0230 USA Tel (858) 534-2307 droemmich@ucsd.edu Janet Sprintall MailCode0230ScrippsInstitutionofOceanography9500GilmanDriveLaJollaCA92093‐0230,U.S.A.Tel:858‐8220589Fax:858‐5349820 jsprintall@ucsd.edu

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Ann Gronell Thresher CSIRO Division of Marine and Atmospheric Research Tel: (03) 62-325-419

Fax: (03) 62-325-123 GPO Box 1538, Hobart, TAS 7001 Ann.Thresher@csiro.au

AcronymsABOM Australian Bureau of Meteorology ADMT Argo data management team AST Argo Steering Team CalCOFI California Cooperative Oceanic Fisheries Investigations

CLIVAR CLIVAR is the World Climate Research Programme (WCRP) project that addresses Climate Variability and Predictability

CSIRO Commonwealth Scientific and Industrial Research Organisation CTD Conductivity, Temperature, and Depth DBCP Data Buoy Cooperation Panel EAC East Australian Current ENACT Tasmanian Database System ENSO El Niño/La Niña-Southern Oscillation EOF empirical orthogonal function EOS Eos, Transactions, American Geophysical Union GCOS Global Climate Observing System GCOS SC GCOS Steering Committee

GEM Gravest Empirical Mode GHRSST Group for High Resolution Sea Surface Temperature GODAE Global Ocean Data Assimilation Experiment GOOS Global Ocean Observing System GSSC GTS Global Telecommunications System IAP/AC InstituteofAtmosphericPhysics,ChineseAcademyofSciencesIMOS IntegratedMarineObservingSystem,UniversityofTasmaniaIOC Intergovernmental Oceanographic Commission IOD Indian Ocean Dipole IRD InstitutdeRecherchepourleDéveloppementITCZ Intertropical Convergence Zone ITF Indonesian Throughflow JCOMM Joint Commission for Oceanography and Marine Meteorology JCOMM SOT JCOMM Ship Observations Team JCOMM OCG JCOMM Observations Coordination Group JCOMMOPS JCOMM Observing Platform Support Centre MHT Meridional Heat Transport

28

MLD Mixed Layer Depth NECC North Equatorial Counter Current NEUC North Equatorial Under Current NIO NationalInstituteofOceanography,IndiaNOAA National Oceanic and Atmospheric Administration NODC National Oceanographic Data Center NSF National Science Foundation ODA Ocean Data Assimilation OHC Ocean Heat Content OOPC Ocean Observations Panel for Climate PDV Pacific Decadal Variability PI Principal Investigator SCOR Scientific Committee on Oceanic Research SIO Scripps Institute of Oceanography SOOPIP Ship Of Opportunity Programme Implementation Panel SSH Sea Surface Height SST Sea Surface Temperature TACE Tropical Atlantic Climate Experiment TSG Thermosalinograph UAA UCT University of Cape Town UK United Kingdom US United States WMO World Meteorological Organization WO8 World Ocean Database 2008 WOD World Ocean Database XBT eXpendable Bathythermograph XCTD eXapendable CTD XST XBT Science Team