Prsentation PowerPoint

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" The Kyoto Protocole requires nations to monitor
their "national" carbon sources and sinks, and
that interannual and seasonal resolution is
required to constraint both oceanic and
terrestrial budgets versus emissions  (Ocean
Observation Panel for Climate).
2
SOCOVV Workshop (IOCCP-SOLAS-IMBER-GCP) UnesCO2,
Paris France, 11-14 April 2007
Ocean Carbon Sources and Sinks Regional View 5
Southern and Indian Oceans N.Metzl,
LOCEAN-IPSL
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Southern and Indian Oceans OISO cruises onboard
R.V. Marion-Dufresne
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Seasonality in South Indian Ocean Large
Variations in all Regions
Metzl et al., 2001, 2006 DSR
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Seasonal cycle in the Sub-Antarctic Zones (well
observed) Western and Eastern Indian Ocean,
Monthly Mean 1991-1995 (Sink -0.4 PgC/yr in the
Indian SAZ)
Winter equil
Seasonal Range 60 µatm
Summer sink
Metzl, Tilbrook and Poisson. 1999, Tellus
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Seasonality in South Indian Ocean Large
Variations in all Regions
Metzl et al., 2001, 2006 DSR
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SOCOVV Workshop (IOCCP-SOLAS-IMBER-GCP) UnesCO2,
Paris, 11-14 April 2007
Changes of air-sea CO2 fluxes in the Southern
Oceans N.Metzl, LOCEAN-IPSL thanks to many
contributors and in recent days and weeks
special contributions from A.Lenton, C. Le Quéré,
T.Takahashi, B. Tilbrook, M. Ishii O. Aumont, K.
Rodgers, L. Bopp, N. Gruber, N. Lovenduski, B. Mc
Neil, S. Doney, P. Bousquet, P. Peylin, C.
Rödenbeck
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• Why focussing on air-sea CO2 fluxes in high
  latitude gt 50S today ?
• Recent progress on seasonal and
  interannual-decadal variabilities (from
  observations and models, see also C. Rödenbeck
  talk, soon)
• - Future Large changes in high latitudes (more
  vulnerable ?) suggested by climate / carbon cycle
  coupled models

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Air-Sea CO2 fluxes, new climatology, Takahashi et
al. (2007, subm.)
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Only one region is a CO2 source Southern Ocean
in July-October
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Changes of air-sea CO2 fluxes
Strong sink
Small sink/source
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Back some years ago
Good !?
OCMIP II models -0.42 Pg/yr, Climatology, -0.35/
-0.5 Pg/yr !!!! Annual flux seems correct, but
..
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Annual flux was coherent, but..opposed
seasonality !!! biological and mixing processes
not correct in ocean models
S.O. gt 50S
Summer sink
Winter sink
summer
(Takahashi et al., 2002, J.Orr, pers. comm)
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Changes this is not Variability, not
Vulnerability
Wrong
Why small sink ?
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Seasonality in South Indian Ocean Large
Variations in all Regions
Metzl et al., 2001, 2006 DSR
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New pCO2 observations during Austral Winter, few
data but some in each basin
June-Sept data used by Takahashi et al 2007
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Changes of Air-Sea CO2 fluxes in the Southern
Ocean (gt50S) Changes..in Climatologies
(Takahashi et al., 2002, 2007) (main reason
much more observations during austral winter)
Takahashi et al., 2002, 2007
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Recent ocean carbon cycle models ECOCCSM (S.
Doney, N. Lovenduski), S. Doneys talk, soon
ORCA-PISCES (O. Aumont, L. Bopp, A. Lenton)
ORCA-PISCES-T (C. Le Quéré et al.)
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Annual air-sea CO2 flux in the Southern Hemisphere
New climatology (Takahashi et al., 2007, fig.
Gruber et al 2007)
Ocean Model (ORCA-PISCES)
Total gt 50S -0.05 PgC/yr
Total gt 50S -0.06 PgC/yr
Coherent view for annual CO2 flux
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Seasonal cycle relatively well reproduced by new
ocean models
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Seasonal DpCO2 cycle in the Southern Ocean low
in summer, high in winter and never very far from
equilibirum
Seasonal range 20-30 µatm
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Air-Sea CO2 fluxes in the Southern
Ocean Seasonality now well observed and maybe
well simulated (better representation of
biological activity and mixed-layer) What about
the long term changes ???
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Interannual CO2 flux in the Southern Ocean
gt50S A view from an ocean model (between -0.1
and 0.1 PgC/yr)
-0.05 PgC/yr (Takahashi et al., 2007)
Model A. Lenton, K. Rodgers, O.Aumont, L. Bopp
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Detecting the decadal sea surface pCO2 trends (1)
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Meridional distributions of CO2 concentration and
SSTin austral summers
Latitude
Inoue and Ishii, Tellus 57B, 58-69, 2005.
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Trend of the CO2 concentration in the Southern
Oceanto the south of western Australia in January
Inoue and Ishii, Tellus 57B, 58-69, 2005.
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Detecting the decadal sea surface pCO2 trends (2)
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Interannual Variability Observed in the Southern
Indian Ocean (6 OISO cruises conducted in the
same region during January)
Interannual Range 50 µatm
Air 2004
Air 1998
SIZ
POOZ
Metzl, IGBPnews 2005, and unp. res.
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Selection MINERVE and OISO cruises 1991- 2000
Poisson et al. 1993 Metzl et al., 2005
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Seasonal pCO2/SST relation
Metzl et al., 2005, ICDC7
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Back to the sixties Ocean pCO2 changes in the
south-western Indian Ocean 1962/2000
Waterman, 1965 Metzl et al 2005, ICDC7
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Decadal variations in the South Indian Ocean
1962-1991-2000
Metzl et al, 2005, ICDC7
Origins of changes Warming, primary prod., E-P,
external forcing (SAM ) ????
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Observed decadal pCO2 trends in the South Indian
Ocean from 1962 to 2000
Atmosphere 49 µatm, 1.3 µatm/yr Ocean in
warm water 42 µatm, 1.1 µatm/yr Ocean in cold
water 55 µatm, 1.4 µatm/yr
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Detecting the decadal sea surface pCO2 trends (3)
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Decadal trend based on winter pCO2 south of
50S (here for SST between 1.5-2.5 C)
Takahashi et al., 2007
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Synthesis Observed decadal changes in atmosphere
and sea surface CO2 in the Southern Ocean (Inoue
and Ishii, 05 Metzl et al., 05 Takahashi et
al., 07)
Atmosphere pCO2 1.3 to 1.6 µatm/yr
No large change of the flux in models ?
Ocean pCO2 1.2 to 2 µatm/yr
But ocean pH decreases 0.07 since 40 years
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SCO2P (Scoop, Surface CO2 Problem)
OISO-15, January 2007
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Interannual variations very large change in the
SBT and SAZ regions. In Jan 2007 warmer ocean
pCO2 gtgtgt atm. pCO2
50 µatm
SST anomalies, 1.5C
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SOCOVV Workshop (IOCCP-SOLAS-IMBER-GCP) UnesCO2,
Paris France, 11-14 April 2007
Ocean Carbon Sources and Sinks, Regional View 5
Southern and Indian Oceans
Message 1 Seasonality and annual CO2
flux Southern Ocean CO2 sink is low around
-0.05 PgC/yr Message 2 Interannual-decadal
variability Observations Oceanic CO2 increase
close to atm. CO2 increase Message 3 but large
and rapid changes also occur (e.g. recent warming
in subtropical Indian Ocean and large variations
observed in high latitudes). These changes need
to be explained and simulated to better
understand future scenarios and feedbacks.
" The Kyoto Protocole requires nations to monitor
their "national" carbon sources and sinks, and
that interannual and seasonal resolution is
required to constraint both oceanic and
terrestrial budgets versus emissions  (Ocean
Observation Panel for Climate).