1 / 28

Oceanic Constraints on the Size of the Terrestrial CO 2 Fertilization Sink

Oceanic Constraints on the Size of the Terrestrial CO 2 Fertilization Sink. A joint atmosphere-ocean inversion New air-sea fluxes No “regularization” A large CO 2 fertilization is sink not needed Why do we get this result? Is it reliable?.

xuxa
Download Presentation

Oceanic Constraints on the Size of the Terrestrial CO 2 Fertilization Sink

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Oceanic Constraints on the Size of the Terrestrial CO2 Fertilization Sink • A joint atmosphere-ocean inversion • New air-sea fluxes • No “regularization” • A large CO2 fertilization is sink not needed • Why do we get this result? Is it reliable? Andy Jacobson, Jorge L. Sarmiento, Manuel Gloor, Niki Gruber, and Sara Mikaloff Fletcher Atmospheric transport estimates: TransCom3 modelers, Atmospheric observations: NOAA CMDL Globalview-CO2 Program, GLODAP Ocean Carbon Survey: Robert M. Key, Richard Feely, Chris Sabine

  2. Flux Comparison Fluxes for tropical land regions and southern land regions are correlated cannot be reliably estimated separately. Positive flux: source to atmosphere Land-air flux ± 1 s.d. 80% CI mean Sea-air flux

  3. How much of the answer comes from data? Transport model: MATCH (R. Law)

  4. How much of the answer comes from data? Transport model: MATCH (R. Law)

  5. How much of the answer comes from data? Transport model: MATCH (R. Law)

  6. How much of the answer comes from data? Transport model: MATCH (R. Law)

  7. How much of the answer comes from data? Transport model: MATCH (R. Law)

  8. Joint Inverse: Ocean Flux Constraints Key atmospheric inversions TransCom3 L2 control inversion result (Gurney et al. 2004) Takahashi (1999) Takahashi (2002) MOM3 Forward sims ocean inversions

  9. Joint Inverse: Ocean Flux Constraints Key atmospheric inversions TransCom3 L2 control inversion result (Gurney et al. 2004) Takahashi (1999) Takahashi (2002) MOM3 Forward sims ocean inversions

  10. Joint Inverse: Ocean Flux Constraints Key atmospheric inversions TransCom3 L2 control inversion result (Gurney et al. 2004) Takahashi (1999) Takahashi (2002) MOM3 Forward sims ocean inversions

  11. Joint Inverse: Ocean Flux Constraints Key atmospheric inversions TransCom3 L2 control inversion result (Gurney et al. 2004) Takahashi (1999) Takahashi (2002) MOM3 Forward sims ocean inversions

  12. Oceanic Constraints on Terrestrial Fluxes • Independent Fluxes • Reject zero at 95% confidence level for T+SL flux. • 77% probability that the T+SL flux is greater than 1.0 PgC/yr (vs. 49% previous best guess).

  13. Implications for a CO2 Fertilization Sink Residual ~0 ± 1 PgC/yr Small residual flux is not compatible with the existence of a large fertilization sink in the tropics.

  14. Air-Sea Flux ComparisonContemporary Fluxes 1992-6

  15. Air-Sea Flux ComparisonContemporary Fluxes 1992-6

  16. Anthropogenic and Preindustrial Flux Estimates

  17. Anthropogenic and Preindustrial Flux Estimates

  18. Anthropogenic and Preindustrial Flux Estimates

  19. C* = DIC - Cbio = Cgasex + Cant + const

  20. Can Forward Models be so Wrong? Ocean uptake Ocean outgassing Zonally-averaged air-sea fluxes [Murnane et al. 1999]. In the Southern Ocean, a modest net flux is the result of large, offsetting contributions from the solubility pump and from the biological pump.

  21. Can pCO2 Fluxes be so Wrong? The Southern Ocean is undersampled, especially in the winter. Summertime pCO2 is subject to biological drawdown, but wintertime levels may be higher. Figure courtesy of Colm Sweeney

  22. Conclusions • Atmospheric data alone cannot reliably resolve regional fluxes • Ocean interior data constrain air/sea fluxes very strongly • Large tropical & southern land (T&SL) source detected • Magnitude of T&SL source similar to deforestation estimates. Hence, a large CO2 fertilization sink is not needed to close carbon budget.

  23. Partitioning of Sink: Land vs. Ocean -1.1 ± 0.2 PgC/yr -1.7 ± 0.2 PgC/yr Estimates for 1992-96 except where noted; By convention a negative flux represents uptake from the atmosphere; Outgassing of riverine carbon (0.45 PgC/yr) attributed toocean.

  24. Construction of the Joint Inverse Key atmospheric inversions TransCom3 control inversion result Takahashi (1999) Takahashi (2002) MOM3 Forward Sims ocean inversions joint inversions

  25. Oceanic Constraints on Terrestrial Fluxes • Anticorrelated Fluxes • Can we reject zero?

  26. Joint Inversion Constraints 67484 observations in ocean, 76 on land

  27. IPCC Terrestrial Models:Predicted Response to Rising Atmospheric CO2 Concentrations and Climate Change 1980s Fertilization Sink: 0.3 to -3.8 PgC/yr (reported) 4 2 0 -2 CO2 Flux to Atmosphere (PgC yr-1) -4 -6 Hybrid LPJ IBIS SDGVM VECODE Triffid CO2 Effect Only (model range) 1992-96 Fertilization Sink: about -1 to -3.5 PgC/yr (rough estimates from graph) -8 -10 -12 1850 1900 1950 2000 2050 2100

More Related