Constraints on air-sea carbon fluxes from atmospheric potential - PowerPoint PPT Presentation

Constraints on air-sea carbon fluxes from atmospheric potential oxygen Laure Resplandy Scripps Institution of Oceanography R. Keeling (Scripps) ; A. Jacobson (NOAA) ; B. Stephens, J. Bent (NCAR) S. Khatiwala (Oxford, UK) ; C. Rödenbeck (MPI, Germany)

Air-sea CO 2 fluxes Takahashi et al., 2009 � -106 -60 0 60 106 Annual net flux [gC/m2/y]

Air-sea CO 2 fluxes sink source sink Takahashi et al., 2009 � -106 -60 0 60 106 Annual net flux [gC/m2/y]

Air-sea CO 2 fluxes sink source sink Takahashi et al., 2009 � -106 -60 0 60 106 Annual net flux [gC/m2/y] Ocean interior inversion (Jacobson et al., 2007) Ocean surface pCO 2 (Takahashi et al., 2009)

Air-sea CO 2 fluxes (a)symmetry CO 2pi Pacific � Ocean 90S 20S Eq 20N 90N

Air-sea CO 2 fluxes asymmetry CO 2pi Atlantic � Ocean 90S 20S Eq 20N 90N

Air-sea CO 2 fluxes asymmetry CO 2pi CO 2pi transport asymmetry Global Ocean 90S 20S Eq 20N 90N

Air-sea CO 2 fluxes asymmetry CO 2 difference (ppm) Inferred pre-industrial 1 � From 50 yrs � South Pole � � CO 2 data � SPO � � Keeling et al., 2011 0 � -0.8 ppm � � Mauna Loa � -1 MLO � CO 2pi transport asymmetry Global Ocean 90S 20S Eq 20N 90N

Air-sea CO 2 fluxes asymmetry CO 2 difference (ppm) Inferred pre-industrial 1 � From 50 yrs � Ocean South Pole � � CO 2 data � inversion � SPO � � Keeling et al., 2011 Gloor et al, 2003 � 0 � -0.4 ppm -0.8 ppm � � Mauna Loa � -1 MLO � CO 2pi transport asymmetry Global Ocean 90S 20S Eq 20N 90N

Can we further constrain the hemispheric 1 asymmetry? � Atmospheric data: potential oxygen � Where do the biases come from? � 2 Link between heat and carbon ocean transport � Can we improve the air-sea flux prior? � … �

Atmospheric Potential Oxygen tracks air-sea flux O 2 ︸ 1.4 O 2 ︸ Atmospheric Potential Oxygen � 1.1 (Keeling and Manning, review Treatise on Geochem. 2014) � � CO 2 APO = O 2 + 1.1 CO 2 CO 2 CO 2 O 2 CO 2 O 2 South � � � Equator � � � � � � North

Atmospheric Potential Oxygen tracks air-sea flux O 2 ︸ 1.4 Atmospheric Potential Oxygen � (Keeling and Manning, review Treatise on Geochem. 2014) � � CO 2 APO = O 2 + 1.1 CO 2 CO 2 O 2 CO 2 O 2 South � � � Equator � � � � � � North

Atmospheric Potential Oxygen tracks air-sea flux Atmospheric Potential Oxygen � (Keeling and Manning, review Treatise on Geochem. 2014) � � APO = O 2 + 1.1 CO 2 - fossil fuel CO 2 O 2 CO 2 O 2 South � � � Equator � � � � � � North

Airborne atmospheric potential oxygen data B. Stephens, J. Bent (NCAR) 1600 observations ~500 hours of flight Wofsy et al., 2011 APO airborne data (HIPPO) 500 600 pressure (mbar) 700 800 900 950 1000 60S 40S 20S 0 20N 40N 60N 80N 60S � Equator � � � � 80N Latitude APO (per meg) -18 -14 -10 -7 -3 0 3 7 10 14 18 Resplandy et al., in prep � �

Airborne atmospheric potential oxygen data B. Stephens, J. Bent (NCAR) 1600 observations ~500 hours of flight Wofsy et al., 2011 northern deficit ~ 8 per meg APO airborne data (HIPPO) 500 fossil fuel � 600 pressure (mbar) + ocean 700 800 900 950 1000 60S 40S 20S 0 20N 40N 60N 80N 60S � 20S Eq 20N �� � � 80N Latitude APO (per meg) -18 -14 -10 -7 -3 0 3 7 10 14 18 Resplandy et al., in prep � �

Combine atmospheric and oceanic data to constrain ocean transport PREDICTION � DATA � atmospheric atmospheric potential oxygen potential oxygen APO from inverse flux (MIT ECCO) APO airborne data (HIPPO) 500 500 600 600 pressure (mbar) pressure (mbar) 700 700 800 800 900 900 950 950 1000 1000 60S 40S 20S 0 20N 40N 60N 80N 60S 40S 20S 0 20N 40N 60N 80N Latitude � atmospheric transport ocean transport air-sea fluxes + Cant (Khatiwala, 2009) ocean DATA � � +fossil fuel (EDGAR) O 2 *, C*, T � (~60 000 obs.) ocean inversion (Gloor et al., 2001; Gruber et al., 2001; MikaloffFletcher 2007; Jacobson et al., 2007) Resplandy et al., in prep

Potential oxygen to constrain CO 2 asymmetry 1 Ocean inversions northern deficit APO (per meg) -2 MOM-HH MOM-LHS MOM-LL MOM-LL MOM-PSS MOM-PSS MOM-RDS -4 MITgcm-2.8 MIT-ECCO -6 Atmospheric � potential -8 oxygen data � � -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 MLO-SPO CO 2pi [ppm] Resplandy et al., in prep

Potential oxygen to constrain CO 2 asymmetry 1 Ocean inversions northern deficit APO (per meg) 50 yrs CO 2 data � -2 MOM-HH Keeling et al., 2011 MOM-LHS MOM-LL MOM-LL MOM-PSS MOM-PSS MOM-RDS -4 MITgcm-2.8 MIT-ECCO -6 Atmospheric � potential -8 oxygen data � � -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 MLO-SPO CO 2pi [ppm] Resplandy et al., in prep

Potential oxygen to constrain CO 2 asymmetry 1 Ocean inversions northern deficit APO (per meg) 50 yrs CO 2 data � -2 MOM-HH Keeling et al., 2011 MOM-LHS MOM-LL MOM-LL MOM-PSS MOM-PSS MOM-RDS -4 MITgcm-2.8 MIT-ECCO -6 Atmospheric � potential -8 oxygen data � � -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 observational target? MLO-SPO CO 2pi [ppm] � � � CO 2pi ocean transport � ~ -0.6 PgC/y Resplandy et al., in prep

Link between carbon and heat ocean transports 2 Cpi-Heat N transp 2 Ocean inversions 0 MOM-HH 1 MOM-LHS Heat transport [PW] MOM-LL MOM-PSS -1 MOM-RDS MITgcm-2.8 0 MITgcm-ECCO Atlantic Atlantic hydrographic -1 sections � Global Ganachaud & Wunsch, 2003; Macdonald et al., 2003; Alvarez Indo-Pacific -2 et al., 2003; Holfort et al., 1998; Atlantic Lundberg & Haugan, 1996 -1.5 -1.0 -0.5 0.0 0.5 1.0 Cpi transport [PgC/y] pre-industrial carbon transport [Pg/y]

� � Ocean transport asymmetry is underestimated 2 Ocean inversions northern deficit APO (per meg) MOM-PSS -2 MOM-HH MOM-RDS MOM-LHS MITgcm-2.8 MOM-LL MIT-ECCO v1 MOM-PSS � APO troposphere -4 -6 Atmospheric � -8 potential APO data oxygen data � -0.5 0.0 0.5 1.0 meridional heat transport [PW] ocean heat transport asymmetry [PW] Resplandy et al., in prep

� � Ocean transport asymmetry is underestimated 2 Ocean inversions northern deficit APO (per meg) MOM-PSS -2 MOM-HH MOM-RDS MOM-LHS MITgcm-2.8 MOM-LL MIT-ECCO v1 MOM-PSS � APO troposphere Previous estimates -4 Ocean sections � Ganachaud and Wunsch, 2003 Air-sea flux climatology � -6 CORE2 Large and Yeager, 2009 Atmospheric � potential -8 APO data oxygen data � -0.5 0.0 0.5 1.0 meridional heat transport [PW] ocean heat transport asymmetry [PW] observational � target 0.5-1 PW Resplandy et al., in prep

� � Ocean transport asymmetry is underestimated 2 Ocean inversions northern deficit APO (per meg) MOM-PSS -2 MOM-HH MOM-RDS MOM-LHS MITgcm-2.8 MOM-LL MIT-ECCO v1 MOM-PSS � APO troposphere -4 water mass inconsistency � (forward-inverse) “missing” � Atlantic heat � -6 transport “missing” � Atmospheric � Pacific heat � potential -8 transport APO data oxygen data � -0.5 0.0 0.5 1.0 meridional heat transport [PW] ocean heat transport asymmetry [PW] Resplandy et al., in prep

Discussion and prospects • Potential oxygen is a valuable new constraint on air-sea flux � • southward transport of 0.6 PgC/y necessary to explain APO data • Higher resolution ocean: weak impact on inversion � • Ocean models underestimate transports of carbon, heat and oxygen. � • Possible impact on land carbon sinks?