WP 3: Long Term Assessment

1. WP 3: Long Term Assessment • Establish the framework for repeated anthropogenic CO2 (Cant) inventory quantification within the Atlantic Ocean basin, including its polar extensions and the European marginal seas • Create interfaces between CarboOcean activities and related international activities in order to permit global ocean inventory estimates.

2. WP 3 Where did we start? Column inventory of anthropogenic CO2 in the ocean (mol m-2) Net uptake of anthropogenic CO2 (1800-1994): 118 ± 19 Pg C yr-1 = 48% of the emissions after Sabine et al. (2004), Science305, 367-371.

3. WP 3 GLODAP – a product of a decade-long global effort JGOFS/WOCE CO2 survey ( GLODAP)

4. WP 3 CARINA – from a slow start to a CARBOOCEAN legacy CARINA – already a CARBOOCEAN legacy

5. WP 3 Anthropogenic CO2 methodology CARBOOCEAN has populated the zoo of CTant methods Did we agree on THE optimal method? – Not really, but ... Vázquez-Rodríguez et al. (2009), Biogeosciences 6, 439-451.

6. WP 3 Anthropogenic CO2 methodology • Two thing to learn: • the methods are rather robust • the differences point to general weaknesses of general assumptions Vázquez-Rodríguez et al. (2009), Biogeosciences 6, 439-451.

7. WP 3 CARINA – from a slow start to a CARBOOCEAN legacy

8. WP 3 Interior carbon synthesis • Resolutions: • Address decadal carbon change basin by basin • Calculate change in storage of both DIC and CTant • Apply different CTant methods (e.g. DC*, eMLR, TTD) to evaluate robustness of the distributions • Use a model-based analysis to provide „best practices“ recommendation for MLR-based approach • Synthesize basin studies into global picture of the decadal change of interior ocean carbon storage

9. WP 3 Interior carbon synthesis timeline – towards IPCC AR5 2009 2010 2011 2012 Arctic Bates DCant, DDIC interpolation Atlantic Tanhua 2nd QC DCant, DDIC interpolation Pacific Ishii DCant, DDIC interpolation 2nd QC Indian Sabine Interpol 1 Interpol 2 DCant, DDIC Southern Hoppema Data/Methods eMLRdens interpolation Rodgers? Key „best practices“ 6/10 6/11 8/11 3/12 8/12 2nd synthesis Workshops 3rd synthesis Workshop Together with SOCAT Basin-wide Studies completed Global Study completed By ocean basin Regional Synthesis Paper published Global Synthesis Paper published

10. The way beyond CARBOOCEAN: The OceanObs’09 vision

11. The way beyond CARBOOCEAN: Repeat Hydrography Program

12. The way beyond CARBOOCEAN: Repeat Hydrography Program CLIVAR post-CLIVAR WOCE ? ~10 years ~15 years ?

13. How to capture natural spatiotemporal variability DIC t

14. The way beyond CARBOOCEAN: ARGO Oxygen Program

15. The way beyond CARBOOCEAN: ARGO Oxygen Program • Objectives: • Understand oceanic oxygen dynamics in view of their carbon-relevance; • Establish temporal change of oceanic oxygen inventory; • Improve atmospheric O2/N2 constraint on the oceanic uptake of anthropogenic CO2; • Help to interpret and interpolate sparse data from repeat hydrography occupations and ocean time-series; • Refine oxygen boundary condition as a critical information for CTant methods • Aid interpretation of variations in ocean circulation/mixing as well as net community and export production.