Coordinated by:

CARBOOCEANIntegrated Project Contract No. 511176 (GOCE) Global Change and Ecosystems

The big scientific questions – new answers and new challenges

Core Theme 5 Future scenarios for marine carbon sources and

sinks

The questions and challenges:

What is going to happen?

What are the uncertainties associated?

What if deliberate ocean storage comes back as a mitigation option?Integration of carbon observations into an integrated prognostic modelling frame-work:

Operational goal: Best possible science-based projections of ocean carbon sink behaviour for scenarios of future energy use and climatic change will be developed. The initial conditions for the scenarios will be compiled through a combination of observational data and modelling. The models will include formulations of new biogeochemical feedback mechanisms. Data collection and model simulations will be coordinated in particular with marine carbon cycle research activities in the US

Delivery: Assessment of future marine CO2 uptake kinetics based on models and data.

What is going to happen?

MPIIPSL

Sabine et al. 2004

Anthropogenic DIC

WP17 Bopp, Segschneider

ECHAM5 T63L31

JSBACHMPI-OMPE

610 GtC

1860 - 2100CO2 emissions

2200 GtC

HAMOCC5 NPZD

Interface

albedo

photosynthesis,stomatal conductance

phenology

carbon pools1740 GtC

soil, hydrologicaland energy balance

The MPI Climate – Carbon Cycle Model

40.000 GtC

Courtesy Thomas Raddatz

Atmosphere

Ocean

Land-biosphere

WP17 Segschneider

Earth System Model forcing

WP17 Segschneider et al.

WP17 Segschneider, MPI model system

coex90

WP17 Segschneider, MPI model system

PhosphateAtlantic Pacific

Simulated Annual Mean

Year 100[ mol / l ]

Observed WOA05

[ mol / kg ]

Model development, isopycnal HAMOCC/ MICOM, WP17, Karen Assmann, Bergen:

pre-industrial (PI) climate, CO2=280ppm pre-industrial (PI) climate, CO2=316->367ppm

1961-2000 (XX) climate, CO2=280ppm 1961-2000 (XX) climate, CO2=316->367ppm

Net ecosystem production for different LPJ runs (blue CO2 uptake, red CO2 release)

Model development, terrestrial C cycle and Bergen Climate Model, WP17, Kristof Sturm:

Hovmueller diagram showing the global zonal mean evolution of the surface aragonite saturation state at different latitudes. The saturation horizon (thick line) reaches the surface by the year 2050 at high northern latitudes. After the year 2070, high latitude regions will become largely undersaturated.

WP17, Joos et al., Bern

WP17, Joos et al., Bern

Changes in the volume of water with an aragonite saturation state below 1 (undersaturation, green) and between 1 and 2 (red), 2 and 3 (blue), 3 and 4 (grey), and above 4 (orange). By 2100, the saturation is always smaller than 3.

Change in 230Th, equatorial Pacific

Change in 230Th, equat. Pacific, after CaCO3 export 1/3, Heinze et al., 2006, GBC

What are the uncertainties associated (with the predictions)?

Friedlingstein et al., 2006, Journal of Climate,C4MIP

Why Earth system modelling?

year

year

NCAR

WP17

Sabine et al., 2004

Model results CARBOOCEAN

Cant water column inventory

Feb 1995

Takahshi, LDEO webside

Aug 1995Model results CARBOOCEAN

Feb 1995

surface ocean pCO2

Aug 1995

What if deliberate ocean storage comes back as a mitigation option?

(an option we do not really like…)

SPIEGEL ONLINE - 03. Dezember 2006, 10:13 URL: http://www.spiegel.de/wissenschaft/natur/0,1518,451308,00.html

CO2-SPEICHER IM MEER

Teures Seegrab für den Klimakiller*Von Gerd F. Michelis

Um Kohlendioxid von der Atmosphäre fernzuhalten, kann man es einfach im Meer eingelagern - diese Idee wird inzwischen auch in Deutschland ernsthaft geprüft. Experten warnen vor den Risiken. Und vor immensen Kosten für die Stromkunden.

Expensive ”Davy Jones's locker” for the climate killer

Experiments on CO2-droplet rise velocity • Midwater release option adresses

release, rise, and dissolution of liquid CO2 at intermediate (<2800m) water depth

• CO2 droplets dissolve in the process of rising upward due to buoyancy

• during ascend, hydrate forms at CO2-seawater interface, retarding dissolution

• understanding dissolution characterisitcs of CO2 droplets in the flow field is therefore essential for assessing the depths distribution of the released CO2, near injection pH fields etc.

• First adresses experimentally:Rise Velocity

WP18 Rehder, Gust, Allendal et al.

Experimental setup for rise velocities

• Release of single droplets within pressure lab with free control of p, T

• measurment of rise velocity by passing through 2 horizons of known distance by cameras in pressure housing

• size determination by monitoring droplet after focussing its pathway through a funnel to avoid parallax

WP18 Rehder, Gust, Allendal et al.

Observed rise velocities of CO2 droplets in seawater (35PSU)

(a vast amount of work for a couple of lines …)

WP18

pH change, Model (Enstad et al.)

The questions and challenges:

What is going to happen? Spectrum of scenarios needed

What are the uncertainties associated? If not reduction, then at least realistic estimate of uncertainties

What if deliberate ocean storage comes back as a mitigation option? Have accurate scenarios at hand based on processes

Core Theme 5 talks on Tuesday:

13:00-13:15 Laurent Bopp, Overview on future scenarios

13:15-13:30 Thomas Froelicher, "Results from the NCAR CSM1.4-carbon model at Bern

13:30-13:45 Jochen Segschneider, Climate feedback on the carbon cycle

13:45-14:00 Karen Assmann, First results from the isopycnal HAMOCC model in MICOM/BCM

14:00-14:15 Jim Orr, High resolution tracer modeling

14:15-14:30 Gregor Rehder, Overview on deliberate storage