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Dear colleagues, This is a real-virtual
presentation, as I am not present and apologize
for this. Many thanks to Stephane for presenting
to you this short overview of the OISO project
that could be associated to KEOPS next year. If
you have any question or comment regarding
the OISO results, please send me a mail. I wish
you an interesting and productive meeting A
bientot Nicolas
around 50S, here near Kerfix,, the ocean is not
always calm as we wish (font screen, as of
19/1/04) and oceanographic operations have to be
stopped)
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OISO, recall objectives some are also underlined
in KEOPS
Climatology of the Carbon Cycle C3
Study of the pCO2, DIC, TA, C13... variability
(seasonal to interannual) Estimate the air-sea
CO2 fluxes at regional and large scales Estimate
the anthropogenic carbon in the ocean Toward a
robust validation of ocean carbon models
(IGBP/OCMIP) Contraints for atmospheric
inversions (e.g. frame of Kyoto Protocole)
Coupling Carbon Cycle and Climate Change C5
Study of the decadal air-sea CO2 fluxes and
anthropogenic evolution Understanding processes
that explain ocean CO2 variability associated to
climatic signal (e.g. warm/cold events)
Réunion KEOPS, 2-3 Mars 2004, Endoume
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MOTIVATION OISO is an important piece for the
GOOS-CO2 puzzle
Underway pCO2, International cruises Report
SCOR/CO2 meeting, Janvier 2003, Paris
Colors on map Annual Air-Sea CO2 fluxes
(Takahashi et al 2002, DSR)
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MOTIVATION Futur Long-term variations of air-sea
CO2 flux a view from a coupled model IPSL
OPA-HAMOCC3-LMD-SLAVE -IS92a (L.Bopp)
2090-1990
Diff Air-Sea Flux in mol/m2/year
Large changes would occur in the Southern Ocean
why ?
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AIR-SEA CO2 FLUXES IN THE SOUTHERN OCEAN
Comparing the view from the ocean (observations
and models) and the view from the atmospheric
inversion.
OISO observations in summer and winter, and
biogeochemical model indicate that the Southern
Ocean is a CO2 sink during austral summer but a
CO2 source during winter (Metzl et al., 2001,
2003).Therefore, the annual sink of 0.5 mol/m2/yr
is low compared to previous estimates This
explains why the CO2 sink is always low in the
S.O. when calculation is based on atmospheric
data (e.g. inversions, using GlobalView, Bousquet
et al., 2000 Gurney et al 2002)
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Message in the first bottle... the Southern
Ocean may not be a large CO2 sink as previously
believed. Observations during winter are
obviously very important to estimate realistic
annual budget More observations, at different
years, are needed to confirm this controversial
result deduced from the OISO cruises in 2000 (no
bug here)..... so let see the next panel...
about interannual variations
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Message in the second bottle... The Southern
Ocean may be a source, even during summer (e.g.
2002) The large CO2 sink in 1998 in the POOZ was
controled by high productivity and associated to
a warm anomaly (maybe related to 1997-ENSO
through atmospheric bridge). Very low silicates
(lt2 µM) and low CO2 around 50-57S suggests that
production may not be limited in the POOZ if
clouds (and light) conditions are good enough
is the S.O. always HNLC ? not certain... Keops
and OISO in 2005 may help to understand this
paradox. For detail on this analysis see
Jabaud-Jan et al, GBC in press just send me a
couriel
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Meso-scale processes coupling SST, Fluo, fCO2
and ADCP data very interesting to explain the
air-sea CO2 flux variability (Track Reunion-60S,
OISO-6, January 2001)
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Message in the third bottle... In the
circumpolar front zone, the meso-scale dynamic
(eddies, meanders, filament...) is certainly
governing the high variability of air-sea CO2
fluxes in Global Ocean models or in
Climatologies, this scale is not resolved
! Details observations during several days in
the same region, as will be performed during
KEOPS, will help to understand the relevant
scales to parameterize the coupling of physical
and biogeochemical processes. we ll see more
about this with the most recent observations....
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Coupling dynamics, production and air-sea CO2
fluxes During OISO-11, strong signals in the
40-45S band for both sea level anomaly and Chla
Sea-level anomaly, Jan 04
SeaWIFS Chla, Jan 04
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SeaWIFS Chla, January 2004, zoom in KEOPS region
During the OISO cruise at 50S CO2 was high in
the West (66-68E) and low in the East (72-74E
of kerguelen
?pCO260 µatm
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The large SLA and Chla signals around 40-45S are
also clearly observed in all properties measured
onboard at the same period (Jan 1004)
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Section from 28 to 60S during OISO-11 T,S, AT
et DIC
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Message in the fourth bottle... Coupling
in-situ and satellite data (altimetry and color
of the sea) is a very important tool to
understand what creates and maintain the regional
characteristics of ocean biogeochemistry During
KEOPS in January 2005, the availibility of
both altimetry and sea-color onboard would be
very helpful. (the bloom South-East off
Kerguelen, is not always present in the same
sector)
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Have a nice day, see you in Kerguelen...