13 April, 2007

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Ocean circulation around New Caledonia, downscaling of Pacific ocean climate and Impacts on issues relevant to island societies Patrick MARCHESIELLO IRD LEGOS 13 April, 2007

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Ocean circulation around New Caledonia, downscaling of Pacific ocean climate and Impacts on issues relevant to island societies Patrick MARCHESIELLO IRD LEGOS. 13 April, 2007. South-west Pacific circulation… Heading toward finer scales. - PowerPoint PPT Presentation

Transcript of 13 April, 2007

Page 1: 13 April, 2007

Ocean circulation around New Caledonia, downscaling of Pacific ocean climate and

Impacts on issues relevant to island societies

Patrick MARCHESIELLO IRD LEGOS

13 April, 2007

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South-west Pacific circulation…

Heading toward finer scales

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Short story of Physical Oceanography in the New Caledonia

-1969: a network of oceanographic observations using merchant ships was initiated by the IRD. The focus is on the large scale, although Hénin (1982, …) compiles the first climatology of the New Caledonia region.

- 1994: The New Caledonia program ZoNéCo support the creation of a network of coastal stations. Delcroix and Lenormand (1997) compile regional data and show the characteristics of ENSO in the region.

- 2000-2005: the downscaling effort is pushed further, with the development of the coastal network and a modeling activity.

STCC

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Climatology (1972-1992)Climatology (1972-1992)

Annual mean surface temperature (a) et salinity (b) computed from in-situ data collected from 1972 to 1992 in the New Caledonia region (Delcroix et Lenormand, 1997)

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Caledonia upwelling discoveryCaledonia upwelling discovery

Hénin et Cresswell, 2005

- Seasonality ?- Alongshore extension ?

Satellite SST for February 2003

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Development of the coastal Development of the coastal network (1994-2006)network (1994-2006)

thermosalinographe SEA-BIRD SBE16

Onset temperature sensor

Koumac

Stations

mooring

Futurestation

Phare Amédée F. Gallois

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Seasonality of upwellingSeasonality of upwellingAlory et al., 2006Alory et al., 2006

Eté

Hiver

Upwelling is apparent in summer only because the winter thermocline is deeper than the upwelling cell can reach

Thermocline

Upwelling cell

nutriens

nutrients

20 m

120 m

100 m

20 m

120 m

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Refining our understanding of Refining our understanding of spatial variations: Modelsspatial variations: Models

A regional model (ROMS) is embedded into a large scale model (MERCATOR) to perform a high resolution reanalysis (Marchesiello et al., 2006).

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Model validationModel validation

Onset Depth Time serie Location ROMSvar(°C)

Obs. var(°C)

Bias (°C)

R N° of Obs

Sabine 10 m Nov98-Feb04 15.9°S, 166.1°E 1.13 0.80 -0.26 0.78 919

Surprises 10 m Sep97-Dec04 18.3°S, 163.0°E 1.10 0.63 -0.12 0.73 633

Uitoe 1 10 m Sep99-Mar-06 21.8°S, 166.1°E 0.65 0.55 -0.72 0.69 633

Uitoe 2 35 m Jul01-Mar-06 21.8°S, 166.1°E 0.30 0.22 0.26 0.47 816

Uitoe 3 62 m Jul01-Mar-06 21.8°S, 166.1°E 0.18 0.29 0.25 0.46 669

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Animation:J. Lefèvre

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Circulation around the barrier reefCirculation around the barrier reef

Current measurments with a glider (Gourdeau, 2006)

Surface Temperature and currents in ROMS (Atlas hydrodynamique, Vega et al., 2006)

Température satellite

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Applications: regional impacts of Applications: regional impacts of climate variabilityclimate variability

• ENSO and climate: downscaling

• Impacts of climate changes:– Ecosystem, Fisheries– Tropical Cyclones– Tropical diseases: Dengue …

• Operational Oceanography: Survey and forecast

• Data distribution

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Tuna-Environment relationTuna-Environment relation

160 165 170

-25

-20

-15

160 165 170

-25

-20

-15

160 165 170-2

5-2

0-1

5

Distribution: Nord-Ouestde la ZEE (Chesterfield –Lansdowne).

Distribution: Ouest de la ZEE (Chesterfield) et IlesLoyautés

Distribution: Sud de la grande Terre (englobantles Iles Loyautés et l’Iledes Pins) .

Thon germon

Thon jaune

Thon obèse

IRD-CPS projects supported by ZoNéCo for 2007-2008

Integrated approach by coupling models: • physics (ROMS)• Plankton ecosystem (PISCES) • Prey and tuna (SEAPODYM)

K. Briand, ZoNéCo

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Cyclones & ClimateCyclones & Climate

Project supported by ANR for 2007-2009

•Downscaling mechanisms of ENSO and ENSO changes under global warming hypothesis.

• Impact on extreme events: Tropical Cyclones in the Caledonia region

Simulation of Erica - March 2003

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Climate and DengueClimate and Dengue

Modeling the Risk of dengue Regional modeling

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Operational Oceanography:Operational Oceanography:survey and forecastsurvey and forecast

Survey:Real-time Web distribution of coastal station data

Forecast:Web distribution of model forecast

Support: project PREVIMER

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Data DistributionData Distribution1. Choix de la donnée

2. Selection de la région

3. Affichage graphique du résultat

Development of data server allowing access and extraction of model output and observation data for the Caledonia region