AtmosphericoxygenconstraintsonSouthernOceanair-seaCO2 fluxseasonality

BrittonStephens,MatthewLong,RalphKeeling,Colm Sweeney,EricKort,EricMorgan,JonathanBent,KathrynMcKain,SaraMikaloff-Fletcher,Prabir Patra

[Image:JonathanBent]

Outline:1) Backgroundandmotivation

2) TheORCAScampaign

• CampaignmeanO2:CO2 ratio

• CampaignmeanCO2 gradient

3) PalmerStationandSouthPoleFlasks

• Interannual variability

• WintertimeCO2 gradients

SeasonalCO2andO2forcings(Sof44S)

CO2

CO2

O2

O2

Total(obs)Thermal(SST,Q)Non-thermal

Models:Anav etal.,J.Clim.,2013Obs:dash=Takahashietal.DSR,2009

M.Long,S.Doney,C.LeQuéré,J.Dunneblack=GarciaandKeeling,JGR 2001

MattLongandTimScheitlin,NCAR

https://youtu.be/VUwOAVh6CGQ𝛿(𝑂$ 𝑁$⁄ ) = ()* +*⁄ ),-./01

()* +*⁄ )213121451− 1 x106

“permeg”

http://www.eol.ucar.edu/field_projects/orcas

NSF/NCAR GVPuntaArenas,Chile15Janto29Feb2016

PrincipleInvestigators:BrittonStephens(NCAR/EOL),MattLong(NCAR/CGD),RalphKeeling(Scripps),EricKort(U.Mich.),Colm Sweeney(CU/NOAA),ElliotAtlas(U.Miami),MichelleGierach (JPL)CarbonCycleInstruments:JonathanBent(NCAR/EOL),BruceDaube(Harvard),KathrynMcKain (CU),EricMorgan(Scripps),TimNewberger (NOAA),MackenzieSmith(UMich.),AndyWatt(NCAR/EOL),SteveWofsy(Harvard)BiogenicReactiveGasInstruments:EricApel (NCAR/ACOM),NicolaBlake(UCIrvine),ValeriaDonets(U.Miami),AlanHills(NCAR/ACOM),BeckyHornbrook (NCAR/ACOM),RichLueb (NCAR/EOL),SueSchauffler(NCAR/ACOM),JoannaCasey(CU)PRISMRemoteSensing:ErnestoDiaz(JPL),HeidiDierssen (U.Conn.),RobertGreen(JPL),JustinHaag(JPL),IanMcCubbin (JPL),Pantazis Mouroulis (JPL),ScottNolte(JPL),DavidThompson(JPL),ByronVanGorp (JPL),KateRandolph(U.Conn.),KatSmith(CU)AerosolandCloudMicrophysicsInstruments:Minghui Diao (SanJoseState),AndrewGettleman (NCAR/CGD),JorgenJensen(NCAR/EOL),BryanRainwater(CU),JeffStith(NCAR/EOL),DarinToohey (CU)Forecastingsupport:JimBresch (NCAR/MMM),ShawnHonomichi (NCAR/ACOM),JordanPowers(NCAR/MMM)AtmosphereandClimateModeling:AbhishekChatterjee(GMAO),MartinHoecker-Martinez(U.Mich.),Jean-FrancoisLamarque (NCAR/CGD/ACOM),FrancisVitt (NCAR/ACOM/CGD)EducationandOutreach:AlisonRockwell(NCAR/EOL),TeriEastburn (UCAR),NikkiLovenduski (CU)ExternalCollaborators:NicolasCassar (Duke),ScottDoney (PALTER),HughDucklow (PALTER),OscarSchofield(PALTER),JorgeSarmiento(SOCCOM),LynneTalley(SOCCOM)

ORCASScienceTeam

ORCASwasprimarilysupportedbyNSFPolarProgramsandLAOF.AdditionalsupportfromNSFAtmosphericChemistryandNASAOceanBiologyandBiogeochemistry

MattLongandTimScheitlin,NCAR

https://youtu.be/VUwOAVh6CGQ𝛿(𝑂$ 𝑁$⁄ ) = ()* +*⁄ ),-./01

()* +*⁄ )213121451− 1 x106

“permeg”

https://youtu.be/Df2peaFxUAM

ORCASResearchFlight3

https://youtu.be/Df2peaFxUAM

ORCASResearchFlight3

Wholecampaignlat/altbinaverages

permeg

O2 CO2

ppm

Alt

Lat

WholecampaignbinaveragedO2:CO2 relationship

adjustedforFFandLND

CESM(SD)ComparedtoObservations

CO2 O2

• ImpliesCO2 rightforwrongreasons

• Onepossibility=compensatingoverestimatesofbothbiologicalandthermalforcing

CESM(SD)CO2 Components CAMOceanCO2 Comparison

LargedisagreementwithclimatologicalCO2 fluxestimates,possiblyrelatedto1)climatologies,2)fossil/landcontributions,3)atmospherictransport,3)spatio-temporalfluxdistributions,4)IAV

MattLongandTimScheitlin,NCAR

https://youtu.be/VUwOAVh6CGQ𝛿(𝑂$ 𝑁$⁄ ) = ()* +*⁄ ),-./01

()* +*⁄ )213121451− 1 x106

“permeg”

O2 vs.CO2

O2CO2

PalmerStationminusSouthPoleseasonalO2 andCO2gradients,adjustedforFFandLND

SouthernOcean(>44S)O2 andCO2 fluxes.Tak09/GK01=Takahashietal.,2009CO2fluxes+GarciaandKeeling,2001seasonalO2 fluxes+Gruberetal,2001annualO2fluxes.Observationalcontraint onratiosshowninmagenta.

ORCASratioconstraintPSA-SPO ratioconstraint(± SE)

IfCESMCO2 fluxcorrect IfGK01O2 fluxcorrect

Summary• ORCASmeasuredpredominantlynegativeCO2:O2 correlationsreflectingthe

dominanceofbiologicaldriversonsummertimeCO2 fluxes• TheCESM forecastproductoverestimatedobservedO2 signalsbutshowed

remarkableagreementwithCO2 gradients,whichwerethemselvesmuchstrongerthanclimatologicalestimates

• PSA-SPOgradientsarelimitedbysparsesamplingbutmayalsoindicatesignificantIAVandpossibleunderestimationoffluxseasonalitybyclimatologies

• ORCASdataarepubliclyavailableandthereispotentialtoleveragemanysynergisticobservationsintheregion