Core theme 5: Future scenarios for marine carbon sources and sinks EU FP6 Integrated Project CARBOOCEAN ”Marine carbon sources and sinks assessment” 3rd Annual Meeting – Bremen Germany 4-7 December 2007

Objectives of CARBOOCEAN IP Guiding sustainable development management CO 2 emmisions Objective 5: Prediction, future assessment Initial conditions Objective 1: Short-term assessment System dynamicsBoundary conditions Objective 3: Assessment of Regional European Contribution Objective 2: Long term assessment Objective 4: Assessment of feedbacks

WP11 Model performance assessment and initial fields for scenarios. Objectives and deliverables To determine, how well biogeochemical ocean general circulation models (BOGCMs) are able to reproduce carbon cycle observations from the real world with respect to temporal and spatial distributions To refine criteria for model performance with respect to observations and other models To establish a quality check for the initial conditions for future scenarios with BOGCMs D11.3 (Version 2) Quality assessment of present day BOGCM simulations in form of written summary. This deliverable is delivered but will be extended to include further Earth system models. (Extended to month 30 as revised version). D11.6 Extended comparison between model and observations and consistency check with other model approaches. Breakdown into regions (data synthesis regions, comparison with inverse analyses). Addition of CFCs and natural 14C (natural) for off-line model circulations. Addition of analysis of nutrient and oxygen fields. (Month 36). D 11.7 Atmospheric pCO2 comparison model/observations. (Month 42) D 11.8 Analysis of the decadal variability in the ocean biogeochemical models and of the comparability model/observations for DIC, O2, nutrients, and further carbon cycle tracers. (Month 42)

The ocean carbon sink is at work indeed: Observation derived, Sabine et al., Science, 2004 (not CARBOOCEAN) Water column inventories for anthropogenic carbon [moles m -2 ], hot spots at deep water production areas: CARBOOCEAN models isopycnic MICOM, Univ. Bergen z-level: NCAR/Univ.Bern PISCES/NEMO IPSL OM/HAMOCC MPI-MET D11.3 Assmann&Bentsen

Evolution of model pCO 2 along 20°W, Iceland to 50°N SYN Forcing CLIM Forcing ΔpCO 2 Trend December ppm/yr January ppm/yr ΔpCO 2 Trend December 0.28 ppm/yr January 0.30 ppm/yr Atmospheric (D&J) & oceanic (D&J) pCO2 ΔpCO2 (D&J) Karen Assmann (Univ. Bergen) D11.6, D11.8 Karen Assmann

WP17. Coupled climate carbon cycle simulations. Objectives and deliverables To provide standard set ups of coupled carbon-climate models including simulations for the present To provide predictions of ocean carbon sources and sinks with the standard model configurations for a standard emission scenario To determine important feedback processes – key regional areas in the response of oceanic carbon cycle to climate change To provide interfaces for the new feedback processes as investigated under WP 16 and core theme 4 D 17.5 Carbon cycle data sets for basic future scenarios from Hadley and Bergen Models (month 36) (partner 1and 33) [extended from previous work plan for Partners 1 and 33]. D 17.8 Further simulations & analysis on the period with IPSL and Bern Models [a. 0 emission after 2100 and b emissions after 2100] (month 36) (Partner 6 and 11) D 17.9 Publication on intercomparison of oceanic carbon uptake on the period, including other C4MIP models (month 36) (Partner 6 and all) D Analysis of climate change impact on export production of POC, CaCO3 and potential feedback on carbon uptake (month 42) (Partner 11, 6 and 13).

1.Climate-Carbon coupling Results from C4MIP / CARBOOCEAN. Friedlingstein P., P. Cox, R. Betts, L. Bopp, W. von Bloh, V. Brovkin, P. Cadule, S. Doney, M. Eby, I. Fung, G. Bala, J. John, C. Jones, F. Joos, T. Kato, M. Kawamiya, W. Knorr, K. Lindsay, H. D. Matthews, T. Raddatz, P.Rayner, C. Reick, E. Roeckner, K.-G. Schnitzler, R. Schnur, K. Strassmann, A. J.Weaver, C. Yoshikawa, and N. Zeng, Climate –carbon cycle feedback analysis, results from the C4MIP model intercomparison, Journal of Climate, 19 (14): , Evaluation of the CARBOOCEAN/Euroceans coupled models (IPSL, MPIM, Bern models). : Export and Primary production. Schneider B., L. Bopp, M. Gehlen, J. Segschneider, T. L. Frölicher, F. Joos, P. Cadule, P. Friedlingstein, S. C. Doney, and M. J. Behrenfeld, Spatio-temporal variability of marine primary and export production in three global coupled climate carbon cycle models, Biogeosciences Discuss., 4, , Role of changes in THC on future ocean carbon uptake (IPSL model) Swingedouw D., L. Bopp, A. Matras, and P. Braconnot, Effect of land-ice melting and associated changes in the AMOC result in little overall impact on oceanic CO2 uptake, Geophys. Res. Lett. In press, Published and in press articles :

4. Role of changes in calcification on future ocean carbon uptake (IPSL model) Gehlen M., R. Gangstø, B. Schneider, L. Bopp, O. Aumont, and C. Ethe, The fate of pelagic CaCO3 production in a high CO2 ocean: a model study, Biogeosciences, 4, , Role of changes in ecosystem structure on future ocean carbon uptake (IPSL model) Bopp L., O. Aumont, P. Cadule, S. Alvain, M. Gehlen, Response of diatoms distribution to global warming and potential implications: A global model study, Geophys. Res. Lett., 32, L19606, doi: /2005GL023653, Role of changes in dust deposition on future ocean carbon uptake (IPSL model) Tagliabue A., L. Bopp, and O. Aumont, Ocean biogeochemistry exhibits contrasting responses to a large scale reduction in dust deposition, Biogeosciences Discuss., 4, , Published and in press articles :

- 11 Climate-Carbon Coupled Models (7 GCMs + 4 EMICs) - Same emissions scenario from 1860 to simulations each : Uncoupled + Coupled 1. Climate-Carbon coupling Results from C4MIP / CARBOOCEAN. All models show a positive feedback bewteen the climate system and the carbon cycle. D17.9 (slide by L. Bopp) (Friedlingstein et al. 2006)

Feedback Analysis : g = –  (  L +  O ) / (1 +  L +  O )  Climate sensitivity to CO2  Ocean and Land carbon sensitivity to atmospheric CO2  Ocean and Land carbon sensitivity to climate  ocean  ocean 1. Climate-Carbon coupling Results from C4MIP / CARBOOCEAN. Uncertainties of ocean uptake response to both increased atm. CO2 and a changing climate D17.9 (slide by L. Bopp)

Mechanisms : -Increasing Sea Surface Temperature decreases CO2 solubility - Decreased Mixing prevents the penetration of C ant. - Decrease in Biological Production reduces the amount of carbon transported to depth.  SST (°C)  MXL (m)  THC (Sv)  O.M export (PgC/y) 1.Climate-Carbon coupling Results from C4MIP / CARBOOCEAN. D17.9 (slide by L. Bopp

2. Evaluation of the coupled models (IPSL, MPIM, Bern models). : Export and Primary production. Left : Observation-based (top) and modelled (others) vertically integrated primary production (PP). Right : Hovmoeller diagrams showing the seasonal variability of vertically integrated PP. (Schneider et al. 2007) D17.10 (slide by L. Bopp)

2. Evaluation of the coupled models (IPSL, MPIM, Bern models). : Export and Primary production. (Schneider et al. 2007) Top: Timeseries of anomalies in primary production (PP) for the global ocean (black lines) and the area of the low-latitude permanently stratified ocean that has annual mean sea surface temperatures above 25°C and dominates the global signal. On the left data from satellite observations are shown, on the right results from the IPSL model. Middle: Timeseries of anomalies in the low-latitude ocean for PP overlaid by stratification and SST anomalies, showing the inverse relationship between climate (stratification, SST) and productivity in both observation-based estimates (left) and the IPSL model (right). Bottom: maps of cross-correlations of local PP anomalies versus the stratification anomalies averaged over the whole area of the low-latitude ocean from observation-based estimates (left) and the IPSL model (right). D17.10 (slide by L. Bopp)

3 simulations with the same Coupled GCM (1 Control and 2 scenarios) THC (Sv) CTL GW1 GW2 CTL : Control – No Climate Change GW1 : 1xCO2 > 4xCO2 – No additional ice melting in the North GW2 : 1xCO2 > 4xCO2 – Additional ice melting in the North Swingedouw et al. in press. 3. Role of changes in THC on future ocean carbon uptake (IPSL model) 1xCO2 2xCO2 4xCO2 D17.8 (slide by L. Bopp)

3 simulations with the same Coupled GCM (1 Control and 2 scenarios) THC (Sv) CTL GW1 GW2 Cumulative Carbon Uptake (GtC) THC-related SST and SSS effects counter-balance the dynamical effect CTL > GW1 = GW2 Swingedouw et al. in press. 3. Role of changes in THC on future ocean carbon uptake (IPSL model) 1xCO2 2xCO2 4xCO2 D17.8 (slide by L. Bopp)

4. Role of changes in calcification on future ocean carbon uptake (IPSL model) Gehlen et al The effect of rising pCO2 on CaCO3 production and dissolution was quantified by means of model simulations forced with atmospheric CO2 increasing at a rate of 1% per year from 286 ppm to 1144 ppm over a 140 year time-period. The simulation predicts a decrease of CaCO3 production by 27%. The combined change in production and dissolution of CaCO3 yields an excess uptake of CO2 from the atmosphere by the ocean of 5.9 GtC over the period of 140 years.

5. Role of changes in ecosystem structure on future ocean carbon uptake (IPSL model) (Bopp et al. 2005) Simulated changes in the relative abundance of diatoms (4xCO2 – 1xCO2) At 4xCO2, diatoms relative abundance is reduced by more than 10% at the global scale. This simulated change in the ecosystem structure impacts oceanic carbon uptake by reducing the efficiency of the biological pump, thus contributing to the positive feedback between climate change and the ocean carbon cycle. However, our model simulations do not identify this biological mechanism as a first-order process in the response of ocean carbon uptake to climate change. D17.8 (slide by L. Bopp)

6. Role of changes in dust deposition on future ocean carbon uptake (IPSL model) Absolute change in (A) NPP (gC m-2 yr-1), (B) air-sea CO2 exchange (gC m- yr-1), between 2000 and 2100, due to 60% decrease in dust deposition (Mahowald et al. 2006). We find that the ocean biogeochemical cycle of carbon is relatively insensitive to a 60% reduction in Fe input from dust. Overall, there is relatively little impact of reduced aeolian Fe input (<4%) on cumulative CO2 fluxes over 240 years. The lower sensitivity of our model to changes in dust input is primarily due to the more detailed representation of the continental shelf Fe, which was absent in previous models. (Tagliabue et al. 2007) D17.8 (slide by L. Bopp)

from Jerry Tjiputra A first A2 run – currently being compiled with components that we already have: D17.5

LPJ driven by BCM D17.5 Kristof Sturm

Vegetation dynamics Global[60ºN-90ºN][30ºN-60ºN] LPJ-BCM LPJ-ECHAM D17.5 Kristof Sturm

Net Ecosystem Exchange C4MIP (Friedlingstein et al., 2006) Global [60ºN-90ºN] NEE D17.5 Kristof Sturm

Column inventory of C Ant in 1994 (moles m -2 ) Simulated (climatol. NCEP forcing) Observed (Sabine et al. 2004) D17.5 Karen Assmann & Mats Bentsen

WP18. Feasibility study on purposeful carbon storage. Objectives and deliverables To determine the kinetics and phase-transfer reactions between liquid CO2, hydrate, and seawater from laboratory experiments under high pressures. To simulate the near-range dispersion of injected CO2 using these new kinetic constraints and improved meso-scale models for CO2 injection in the deep ocean and at the sea floor To prepare the simulation of the large-scale propagation of injected CO2 and the global ocean’s retention efficiency (using these improved near-range constraints and a global high- resolution model) To provide preliminary quantification of spatial scales for stress on marine biota due to deliberate CO2 injection. D18.3 Parameters for near-range geochemical kinetics and phase transfer for deep ocean storage (month 36) D18.4 Improved quantification of liquid CO2 near-range behaviour at the seafloor (month 30) D18.5 Global scale high resolution modelling of CO2 release (month 36)

Bigalke (IfM GEOMAR) and G. Rehder (IOW) CO2 droplet rise rates as measured in pressure chamber D18.3/18.4

Bigalke (IfM GEOMAR) and G. Rehder (IOW) CO2 droplet rise rates for hydrated droplets and ”clean” droplets Clean droplets rise quicker as currently assumed according to p,T-stability conditions for CO2 hydrate D18.3/18.4

Lachkar et al., 2007, Ocean Science Mixed layer depth CFCl3 inventories D18.5