Core Theme 5 – WP 17

Overview on Future Scenarios

- Update on WP17 work (5 european modelling groups : IPSL, MPIM, Bern, Bergen, Hadley)

- Strong link with Euroceans (FP6-NoE) (WP3.3 Lead : Fortunat Joos) - Ocean part of C4MIP

(Coupled Carbon Cycle - Climate Model Intercomparison Project : an IGBP/AIMES project, Lead : Pierre Friedlingstein)

Laurent Bopp, IPSL/LSCE, Gif, France

On behalf of the WP17 members

Results from C4MIP (Friedlingstein et al. 2006)

W17 CARBON –CLIMATE COUPLING

- 11 Climate-Carbon Coupled Models(7 GCMs + 4 EMICs)

- Same emissions scenario from 1860 to 2100- 2 simulations each : Uncoupled + Coupled

Results from C4MIP

W17 CARBON –CLIMATE COUPLING

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

Part I. More constrains on the term [ Uptake / Atm. pCO2 ]

Use of anthropogenic DIC estimates

Use of other tracers (CFC…)

Mechanisms that explain the models divergence

Part II. More constrains on the term [ Uptake / Climate change ]

Mechanisms that explain the models divergence

Sensivity experiments to explore the mechanisms

Constrains from observations

Part I. More constrains on the term [ Uptake / Atm. pCO2 ]

Use of anthropogenic DIC estimates

Use of other tracers (CFC…)

Mechanisms that explain the models divergence

IPSL-CM2C

IPSL-CM4 MPIM UNIBE/NCAR HADLEY FRCGC

o (PgC/ppm) 1.6 1.1 1.1 0.9 0.8 1.2

Sabine et al. 2004

Anthropogenic DIC

Waugh et al. 2006

Anthropogenic DIC : Regional Scale

IPSL GLODAP (Sabine et al. 2004)

Atl

anti

cP

acif

ic

96.5 GtC106 +/- 17 GtC119 +/- 17 GtC

(Cadule et al.)

Matsumoto et al. 2004, Orr et al. 2003

CFC : Learn from OCMIP

Use other tracers observations to get higher constrain on modelled carbon uptake

CFC11 in the IPSL coupled model

CFC11 inventories (pmol/m2)

IPSL Model

GLODAP

Run offline with the same circulation fields than thecoupled run

Ocean Cant uptake ↔ Volume of light water

Mechanisms that explain the models divergence

y = 258.28x - 194.37

R2 = 0.8747

0

50

100

150

200

250

300

0 0.5 1 1.5 2

Beta (PgC/ppm)

Mix

ed

La

ye

r D

ep

th (

m)

IPSL-CM2C

IPSL-CM4

MPI

UNIBE/CSSM1

HADLEY

FRCGC

Mechanisms that explain the models divergence

Ocean Cant uptake (beta factor) ↔ Volume of light water

0

50

100

150

200

250

0.7 0.9 1.1 1.3 1.5 1.7

Beta (PgC/ppm)

Mix

ed

La

ye

r D

ep

th (

m)

IPSL-CM2C

IPSL-CM4

MPI

UNIBE/CSSM1

HADLEY

FRCGC

From Climatology of Mixed Layer Depth : o = 0.93-0.95

(Boyer de Montegut et al. 2004)

Mechanisms that explain the models divergence

Part II. More constrains on the term [ Uptake / Climate change ]

Mechanisms that explain the models divergence

Sensivity experiments to explore the mechanisms

Constrains from observations ?

IPSL-CM2C

IPSL-CM4 MPIM UNIBE/NCAR HADLEY FRCGC

o (PgC / °C) -30 -16 -22 -17 -24 -46

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.

…..

Mechanisms that explain the models divergenceSST (°C)

MXL (m)

THC (Sv)

O.M export (PgC/y)

0

0.5

1

1.5

2

2.5

3

-50 -40 -30 -20 -10 0

Gamma (PgC/°C)

SS

T (

°C)

IPSL-CM2C

IPSL-CM4

MPI

UNIBE/CSSM1

HADLEY

FRCGC

-2-1.8-1.6-1.4-1.2

-1

-0.8-0.6-0.4-0.2

0

-50 -40 -30 -20 -10 0

Gamma (PgC/°C)

Exp

ort

(P

gC

/yr) IPSL-CM2C

IPSL-CM4

MPI

UNIBE/CSSM1

FRCGC

-10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

-50 -40 -30 -20 -10 0

Gamma (PgC/°C)

TH

C (

Sv)

IPSL-CM2C

IPSL-CM4

MPI

HADLEY

FRCGC

No clear global relationship : Need to break down the responses at regional levels.

-60

-50

-40

-30

-20

-10

0

-50 -40 -30 -20 -10

Gamma (PgC/°C)

Mix

ed L

ayer

Dep

th (

m)

IPSL-CM2C

IPSL-CM4

MPI

UNIBE/CSSM1

HADLEY

FRCGC

3 simulations with the same Coupled GCM (1 Control and 2 scenarios)

THC (Sv)CTL

GW1

GW2

CTL : Control – No Climate ChangeGW1 : 1xCO2 > 4xCO2 – No additional ice melting in the NorthGW2 : 1xCO2 > 4xCO2 – Additional ice melting in the North

Swingedouw et al. subm.

Sensitivity experiment : Role of THC

3 simulations with the same Coupled GCM (1 Control and 2 scenarios)

THC (Sv)CTL

GW1

GW2

CumulativeCarbon Uptake (GtC)

THC-related SST and SSS effects counter-balance the dynamical effect

CTL > GW1 = GW2

Swingedouw et al. subm.

Sensitivity experiment : Role of THC

Constrains from observations on gamma ?

- Interannual / decadal variability of Carbon Fluxes / DIC inventories

: (difficult because model / real years do not match): difficult because of the additional C_ant signal

- Interannual / decadal variability of oceanic O2

- Interannual / decadal variability of atmospheric APO signal.… relation bewteen and the modelled O2 outgassing ?… observed trends in APO ?

Matear et al. 2000(1995-1968)

Motivation : Climate Impact on Carbon Fluxes

How can we test the models ?

Using Oceanic Carbon measurements : difficult because climate effect only a second order impact. First order is the anthopogenic signal

Using Oceanic Oxygen measurements :

impacted by same processes that Carbon : Dyn., Bio. , Thermo. …but no atmospheric signal in the ocean / no chemistry

the O2 oceanic data-base is expanding : several publications have reported changes in O2 concentrations over the last decades and for different basins

North Pacific : Emerson, Ono, Wanatabe, KimSouth Pacific : ShafferSouth Indian : Bindoff and McDougallNorth Atlantic : GarciaSouthern Ocean : Matear…….

Modelling Results

Models compare reasonably well with observed changes

Matear et al. 2000(1995-1968)

Plattner et al. 2002(90s – 70s)

North Pacific

Modelling Results

Models compare reasonably well with observed changes

Deutsch et al. 200590s-80s

North Pacific

New input from CARBOOCEAN

D17.2 CARBON –CLIMATE COUPLING

. 5 new coupled climate-carbon coupled GCMs

. some groups have already completed their runs

Atm

osph

eric

CO

2 D

iffer

ence

(pp

m)

IPSL : +32 ppm

MPI : + 83 ppm

New input from CARBOOCEAN : Oceanic Focus

D17.2 CARBON –CLIMATE COUPLING

ocean ocean

MPIIPSL

- Comparison to observations when possible ?- Comparison of models to determine major mechanisms

Oceanic Focus

ocean ocean

- Comparison of models to determine major mechanisms ofclimate impact

- Comparison to observations (validation, benchmarking, …)