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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.

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Presentation on theme: "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."— Presentation transcript:

1 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)

2 Réunion KEOPS, 2-3 Mars 2004, Endoume 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)

3 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)

4 MOTIVATION: Futur Long-term variations of air-sea CO2 flux a view from a coupled model IPSL: OPA-HAMOCC3-LMD-SLAVE -IS92a (L.Bopp) Large changes would occur in the Southern Ocean; why ? Diff Air-Sea Flux in mol/m2/year

5 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) Comparing the view from the ocean (observations and models) and the view from the atmospheric inversion. AIR-SEA CO2 FLUXES IN THE SOUTHERN OCEAN

6 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

7 Sink in 1998 Source in 2002 OISO reveals large interannual variability of CO2 sources and sinks in the SIZ and the POOZ Sink in 2000 Source in 1998

8 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 (<2 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

9 Meso-scale processes: coupling SST, Fluo, fCO2 and ADCP data very interesting to explain the air-sea CO2 flux variability (Track Reunion-60°S, OISO-6, January 2001)

10 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....

11 Actualities.. Original painting, C.Verdier OISO-11, in the frame of VIGO cruise: 2 January-10 February 2004 O riginal Paiting, Seawifs Chla Jan-04

12 Coupling dynamics, production and air-sea CO2 fluxes: During OISO-11, strong signals in the 40-45°S band for both sea level anomaly and Chla Sea-level anomaly, Jan 04 SeaWIFS Chla, Jan 04

13 SeaWIFS Chla, January 2004, zoom in KEOPS region During the OISO cruise at 50°S CO 2 was high in the West (66-68°E) and low in the East (72-74°E of kerguelen  pCO 2 =60 µatm SOIREE  pCO 2 =30 µatm

14 The large SLA and Chla signals around 40-45°S are also clearly observed in all properties measured onboard at the same period (Jan 1004)

15 Section from 28 to 60°S during OISO-11: T,S, AT et DIC

16 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)

17 Have a nice day, see you in Kerguelen...


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