Post on 28-Jan-2016
description
transcript
Climate sensitivity:
what observations tell us about model predictions
Corinne Le QuéréMax-Planck-Institut für Biogeochemie, Jena, Germany
Acknowledgements:
Laurent Bopp, Karen Kohfeld, Erik Buitenhuis, Olivier Aumont
CO
2 sin
k (
PgC
/y)
(J. Orr and OCMIP-2 participants)
today
no biology, no climate change
time
CO
2 sin
k (
PgC
/y)
(J. Orr and OCMIP-2 participants)
Heimann and Maier-Reimer 1996
no biology, no climate change
time
Prentice et al. 2001, based on data from
Manning 2001, Langenfelds et al.,
1999, and Sabine et al., 2002
Le Quéré et al. 2003
Takahashi et al. 2002
Battle et al. 2000
Gruber and Keeling 2001
CO2 export production
100 yr predictions
100,000 yrs variations
interannual variations
outline
oceanic carbon cycle
Silicifiers
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO
3
Si
CaCO3
DMS
PO
4
NH
4
DOM
biological activity
11
45
34
physical transport
11
33
CO2
CO2 + H2O + CO2-3 2HCO-
3
chemical reactions
90
how do marine ecosystems respond to:
• elevated CO2
• warming• nutrient supply• stratification
physical response to elevated CO2
Reduced CO2 solubility
Reduced vertical circulation
(Sarmiento et al., in prep.)
oceanic carbon cycle
Silicifiers
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO
3
Si
CaCO3
DMS
PO
4
NH
4
DOM
biological activity
11
45
34
physical transport
11
33
CO2
CO2 + H2O + CO2-3 2HCO-
3
chemical reactions
90
diatoms
DOM
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
PO
4
NH4
nutrient-based models
(Najjar et al., 1992; Maier-Reimer 1993)
diatoms
DOM
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
NPZD
PO4 NH4
(Fasham et al., 1993)
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
ecosystem models
PO4 NH4
DOM
(Aumont et al. 2003; Moore et al., 2001)
diatoms
(Bopp 2001)
N
S
equator
lati
tud e
• reduction in nutrient supply
• increase of oligotrophic gyres
• longer growing season
Modelled changes in export production at 2xCO2
+30 %-30 %
CO
2 sin
k (
PgC
/y) climate
feedback
(Prentice et al., 2001)
time
CO
2 sin
k (
PgC
/y)
CO2 + climate
(Prentice et al., 2001)
time
CLI MATE RES PONSE O F OCEAN IC UPTAKE
Sarmientoet al. (1998)
Matear andHirst (1999)
J oos et al.(1999)
T ime Span 1990-2065 1850-2100 1765-2100
Warm ing Eff ect -11% -12% -13%
Circ ulatio n Eff ect -22% -10% -3%
Biological Eff ect +24% +8% +6%
TOTA L -9% -14% -10%
(slide from J. Sarmiento)
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
interannual variations
CO2 export production
100 yr predictions
-5 to -15% [warming] -0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
interannual variations
CO2 (ppm)
0°C
-8°C
280 ppm
200 ppm
5.8°C
1.4°C
960 ppm
550 ppm
Temperature (oC)
400,000 years
100,000 yrs variations
(data from Petit et al., 1999)
x2 over the ocean
• Circulation Changes (Simulation OPA model, O. Marti)
• Increased Sea -Ice in Winter (Crosta et al. 1998)
• Increased dust deposition on the ocean (Mahowald et al. 1999)
• Cooling of SST (CLIMAP 1981)
Model simulations of the last glacial maximum
(Bopp et al., 2003)
total LGM impact on export production
(Bopp et al., 2003)
• decreased export production (-7 %)• decreased atmospheric CO2 (-30 ppm)
gC/m2/y
total LGM impact on export production
(Bopp et al., 2003)
Nano-phyto Diatoms
diatoms relative abundance
Nano-phyto
Diatomées
Latitude
iron LGM impact on export production
• increased export production (+6 %)• but increase of oligotrophic gyres
• shift from nano-phyto to diatoms
•Opal (SiO2)•Calcium Carbonate (CaCO3)•Organic Carbon•Biomarker (C37 Alkenones)
•10Be•231Pa•Excess Barium
•Authigenic Uranium•Authigenic Cadmium•Benthic Foraminifera Fluxes
Age Models•Radiocarbon dating (AMS)•Oxygen Isotope Stratigraphy•Lithogenic Correlation
Flux measurement•Constant Flux Normalization (230Th)•Mass Accumulation Rates•Sediment Concentration
Evaluation of Paleo-Data
Proxy Agreement•How many?•Percentage agreement
Ranking Criteria:
Ranked Classes:
Paleo-Export Proxies:
Data Confidencehigh
medium
low(Kohfeld et al., in prep.)
LGM-Stage 5ad
LGM-today
“Today”
Stage 5ad-today
Stage 5a-d
LGM
dust
CO2
change in export production
(Kohfeld et al., in prep.)
time
Unpublished map not available
Unpublished map not available
/ OPA-PISCES model (Bopp et al. 2003)
(gC m-2 yr-1)
Data-base (Kohfeld et al., in prep.)
change in export production
/ OPA-PISCES model (Bopp et al. 2003)
(gC m-2 yr-1)
Data-base (Kohfeld et al., in prep.)
change in export production
Maximum effect with this model
41 ppm
CO2 drawdown with this model 30 ppm
SST + SSS (+ sea ice + circ.) = –15 ppm
Dust increase –15 ppm
(Bopp et al., 2003)
dust
CO2
Watson et al., 200040 ppm
Archer et al. 20008 ppm
Bopp et al. in press15 ppm
ReferenceCO2 reduction due to dust at the LGM
(Watson et al., 2000)
reasonable agreement considering the phasing of dust/CO2 changes
time
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
Le Quéré et al., in press
CO
2 var
iab
ilit
y (P
g C
/y)
atmosphere
Mean: 3.2 PgC/y
interannual CO2 variability
time
20 years
(Le Quéré et al., 2003)
CO
2 var
iab
ilit
y (P
g C
/y)
atmosphere
ocean
(Bousquet et al., 2000; data from Feely et al., 1999)
equatorial Pacific
During El Nino events: CO2
• warming• decreased upwelling • decreased export production
CO
2 var
iab
ilit
y (P
g C
/y)
MIT model (McKinley 2002)
Hamburg model (Winguth et al., 1994)
OPA model (Le Quéré et al., 2000)
northern sub-tropics
(Peylin et al., in prep)
CO
2 var
iab
ilit
y (m
ol/m
2 /y) MIT model
OPA model
observations
North Atlantic
(Gruber et al., 2002)
Chla (SeaWiFS)
Standard deviation of interannual signal
SST (Reynolds and Smith 1994)
MLD (indirect estimate using SSH)
SSH (TOPEX/Poseidon)
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]+/- 0.05 ppm high lat [circ + bio]
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]+/- 0.05 ppm high lat [circ + bio]
SeaWiFS chla, PP from Behrenfeld and Falkowski (1997), ef-ratio from Laws et al. (2000)
Standard deviation of export production variability 1997-2002 (mol C/m2/yr)1.5
1.0
0.5
0.0
diatoms
DOM
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
PO
4
NH4
nutrient-based models (HAMOCC3)
(Maier-Reimer 1993)
SeaWiFS chla, PP from Behrenfeld and Falkowski (1997), ef-ratio from Laws et al. (2000)
Standard deviation of export production variability (mol C/m2/yr)1.5
1.0
0.5
0.0
HAMOCC3
diatoms
DOM
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
NPZD
PO4 NH4
(Aumont et al.,2002 based on Maier-Reimer and Six 1996)
SeaWiFS chla, PP from Behrenfeld and Falkowski (1997), ef-ratio from Laws et al. (2000)
Standard deviation of export production variability (mol C/m2/yr)1.5
1.0
0.5
0.0
NPZD
HAMOCC3
N2 fixersDMS
producers
CalcifiersNano
phytoplankton
Fe NO3Si
CaCO3
PISCES model based on plankton functional types
PO4 NH4
DOM
diatoms
(Aumont et al., 2003; Bopp et al., 2003)
SeaWiFS chla, PP from Behrenfeld and Falkowski (1997), ef-ratio from Laws et al. (2000)
Standard deviation of export production variability (mol C/m2/yr)1.5
1.0
0.5
0.0
PISCES
NPZD
HAMOCC3
Dynamic Green Ocean Model
N2 fixersDMS
producers
coccolith.Nano
phytoplankton
Fe NO3Si
CaCO3
PO4 NH4
DOM
diatoms
(Buitenhuis et al., 2003)
SeaWiFS chla, PP from Behrenfeld and Falkowski (1997), ef-ratio from Laws et al. (2000)
Standard deviation of export production variability (mol C/m2/yr)1.5
1.0
0.5
0.0
DGOM
4
PISCES
NPZD
HAMOCC3
(Le Quéré et al., in prep.)
diatoms
coccolithophorids
nano-phytoplankton
P
Gro
wth
rat
e
(Chavez et al 2003)
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]+/- 0.05 ppm high lat [circ + bio]
+/- 1%
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.] -25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]- high lat [circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]+/- 0.05 ppm high lat [circ + bio]
+/- 1%
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm -8 to -40 ppm [iron][iron]
-15 ppm -15 ppm [solub.][solub.] -25 to -75 ppm left
~0 ~0 [iron + circ][iron + circ]
+ mid-low lat + mid-low lat [iron][iron]- high lat [circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm
+/- 0.3 ppm tropics +/- 0.3 ppm tropics [circ][circ]
+/- 0.05 ppm mid lat +/- 0.05 ppm mid lat [solub.][solub.]+/- 0.05 ppm high lat [circ + bio]
+/- 1%
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.]
-25 to -75 ppm left-25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]
- high lat - high lat [circ + bio][circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]
+/- 0.05 ppm high lat +/- 0.05 ppm high lat [circ + bio][circ + bio]
+/- 1% +/- 1%
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.]
-25 to -75 ppm left-25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]
- high lat - high lat [circ + bio][circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]
+/- 0.05 ppm high lat +/- 0.05 ppm high lat [circ + bio][circ + bio]
+/- 1% +/- 1%
plankton functional typesplankton functional types
CO2 export production
100 yr predictions
-5 to -15% [warming] 0 to -6% [nutrient supply]- low lat + high lat
100,000 yrs variations
-8 to -40 ppm [iron]-15 ppm [solub.]
-25 to -75 ppm left-25 to -75 ppm left
~0 [iron + circ]+ mid-low lat [iron]
- high lat - high lat [circ + bio][circ + bio]
interannual variations
+/- 0.3 ppm +/- 0.3 ppm tropics [circ]
+/- 0.05 ppm mid lat [solub.]
+/- 0.05 ppm high lat +/- 0.05 ppm high lat [circ + bio][circ + bio]
+/- 1% +/- 1%
plankton functional typesplankton functional types
linkages between biogeochemistry and linkages between biogeochemistry and physics (including the coastal ocean)physics (including the coastal ocean)
CO2 (ppm)
0°C
-8°C
280 ppm
200 ppm
5.8°C
1.4°C
960 ppm
550 ppm
Temperature (oC)
400,000 years
CO2 (ppm)
0°C
-8°C
280 ppm
200 ppm
5.8°C
1.4°C
960 ppm
550 ppm
Temperature (oC)
CO2 (ppm)
0°C
-8°C
280 ppm
200 ppm
Temperature (oC)
400,000 years
5.8°C
1.4°C
960 ppm
550 ppm
1850
JGOFS
2100
Vostok
global