1. GEOF236 CHEMICAL OCEANOGRAPHY (HØST 2012) Christoph Heinze University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research Prof. in Global Carbon Cycle Modelling Allegaten 70, N-5007 Bergen, Norway Phone: +47 55 58 98 44 Fax: +47 55 58 98 83 Mobile phone: +47 975 57 119 Email: christoph.heinze@gfi.uib.nochristoph.heinze@gfi.uib.no DEAR STUDENT AND COLLEAGUE: ”This presentation is for teaching/learning purposes only. Do not use any material of this presentation for any purpose outside course GEOF236, ”Chemical Oceanography”, autumn 2012, University of Bergen. Thank you for your attention.”

2. Sarmiento&Gruber 2006 Chapter 9: Calcium carbonate cycle, part 2

3. Heinze, C., E. Maier-Reimer, and K. Winn, 1991, Glacial pCO 2 reduction by the World Ocean - experiments with the Hamburg Carbon Cycle Model, Paleoceanography, 6, 395-430. Carbon pumps SOLUBILITY

4. The major factor for changing TA is precipitation/dissolution of CaCO 3 : CaCO 3 solid ↔ Ca 2+ + CO 3 2- Carbon in seawater: CO 2 added, carbonate saturation calcium carbonate (calcite, aragonite) So in principle one can neutralise CO 2 gas by dissolving CaCO 3 : CaCO 3 solid + CO 2 gas + H 2 O ↔ Ca 2+ + 2HCO 3 - Over-/undersaturation with respect to CaCO 3 is determined by the solubility product: K sp = [Ca 2+ ] sat x [CO 3 2- ] sat = const. x [CO 3 2- ] sat Therefore: By adding CO 2 we decrease the carbonate saturation. Ω = saturation state = ([CO 3 2- ] actual ∙[Ca 2+ ] actual )/K sp ≈ [CO 3 2- ] actual / [CO 3 2- ] sat

5. Source: Zeebe & Wolf-Gladrow, 2001 Carbon pumps

6. Tucker and Wright (1990) Two different concepts to discriminate between over- and undersaturated areas: Lysocline: Depth interval, where CaCO3 shell material undergoes strong signs of corrosion. Calcium carbonate compensation depth, CCD: depth level, where rain and re-dissolution balance. Therefore: Below the CCD there is no CaCO 3 available anymore.

7. Atlantic Pacific Model Observation GEOSECS Black dots: approximate saturation depth level, using the critical CO 3 2- concentration)

8. CaCO 3 top sediment coverage:

9. Diagenesis model: Model to predict: -solid concentrations in the bioturbated zone -porewater concentrations in the bioturbated zone -flux of dissolved constituents between water column and porewaters -Burial of solid material to “stone” SEE ARCHER ET AL. 1993

10. Diagenesis modelling: Heinze et al., 2009, Paleoceanography

11. Diagenesis modelling: Heinze et al., 2009, Paleoceanography

12. long-term variations (past)

13. CaCO 3 from Eq. Pac. Atmosph. CO 2 Farrell&Prell 1989 Siegenthaler et al., 2005 last 130,000 years

14. Tracer signals – example Atlantic Balsam 1983 Pazific Farrell & Prell 1989

15. Zachos et al., 2005 http://www.fossilmuseum.net/GeologicalTimeMachine.htm

16. T anomaly across the Paleocene-Eocene boundary (Winguth et al., 2010)

17. Van Andel, 1975

19. future evolution

20. Caldeira and Wickett, 2003

21. Direct measurements of C ant in the ocean: Sarmiento&Gruber, 2006

22. Direct measurements of C ant in the ocean: Santana-Casiano et al., GBC, 2007

23. Potential alterations in biological cycling of carbon with circulation and pCO 2 change: 350 μatm (green) 700 μatm (grey) 1050 μ atm (red) Apparent decrease of dissolved inorganic C with pCO 2 Apparent increase of organically bound C with pCO 2 Apparent increase of nutrient utilisiation efficiency with pCO 2 Mesocosm facilities at Espegrend, Bergen Mesocosm experiments at differing atmospheric pCO 2 : ”Captering natural ecosystem communities in plastic bags and watching their behavior for changes in forcing under controlled conditions ” Riebesell, Schulz, Bellerby, Botros, Fritsche, Meyerhöfer, Neill, Nondal, Oschlies, Wohlers & Zöllner, Nature, 2007

24. PTEROPODS (small snails) (aragonite producers) Antarctic pteropod, Fabry et al., Oceanography, 2009 CORALS (aragonite producers) Hoegh-Guldberg et al., Science, 2007

25. Anthroogenic CO 2 emssion scenarios: Raupach et al., 2007, PNAS

26. Aragonite saturation according to future climate projections:

27. Steinacher et al., Biogeosciences, 2009 Aragonite saturation according to future climate projections:

28. Gehlen et al., 2008 CaCO 3 sediment can start to dissolve close to deep-water production areas due to anthropogenic CO 2 :

29. Gehlen et al., 2008 CaCO 3 sediment can start to dissolve close to deep-water production areas due to anthropogenic CO 2 :

30. Gehlen et al., 2008 CaCO 3 sediment can start to dissolve close to deep-water production areas due to anthropogenic CO 2 :

31. CaCO 3 sediment neutralises IPCC AR4, Ch. 7, following Archer, 2005 Archer, 1996 Core top CaCO 3 Ocean is central for long-term uptake and storage of anthropogenic CO 2 : without with CaCO 3 sediment

32. Warm water corals Guinotte&Fabry, 2008

33. Deep water corals Guinotte&Fabry, 2008