Parallel Session : Ocean Atmosphere Coupling (B.Bourlès G.Caniaux)

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Parallel Session : Ocean Atmosphere Coupling

(B.Bourlès – G.Caniaux)

PLAN of the working session :

1. General presentation of AMMA-Ocean & air-sea flux : main objectives & in situ

measurements: (20’)

2. Scientific thematic discussions (introduced by presentations) (2h)

1) SST and West African Monsoon (large scale)

2) Air sea fluxes

3) Ocean circulation in the Eastern Tropical Atlantic

4) Air sea coupling

3. Related programs/studies in Africa and links with EGEE/AMMA (40’)

4. Data bases & satellite data (20’)

5. Miscellaneous (20’)

Thursday 1st of Dec;

planed 14-17h30; delayed due to AMMA-Africa meeting,

where most of the african scientists involved in ocean studies were present.

⇒15h15 – 19h45

⇒24 people attended (9 france, 4 ivory coast, 3 US, 2 nigeria, 2 senegal, 1 benin, 1 togo, 1 netherland, 1 south africa)

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Parallel Session : Ocean Atmosphere Coupling

1. General presentation of AMMA-Ocean - air-sea flux / main objectives / in situ dedicated measurements: (B.Bourlès)

- Recalls on the AMMA Ocean/Air-sea fluxes international organization

- Recall on the main objectives of the Group :

- Presentation of the measurements acquired in the framework of AMMA

and linked international programs (ARGO & CORIOLIS, PIRATA, TAV&TACE CLIVAR):

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Summarize for 2006 :

US NOAA Cruise German IFM-Geomar Cruise French

IRD- MétéoFrance Cruise

Possible Senegal

CRODT-UCAD-IRD cruises

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Parallel Session : Ocean Atmosphere Coupling

2. Thematic discussions:

1) SST & West African Monsoon (large spatial and time scales of variability) :

- Chidong Zang (RSMAS / USA) : Roles of Air-Sea Interaction and the ITCZ In the West African Monsoon

-Mathieu Joly (CNRM / France): SST influences on the interannual variability of the African Monsoon

- Reindert Haarsma (KNMI / Netherland): Low frequency variability in the Atlantic

1st AMMA international meeting, DAKAR, 28 nov. - 2 déc. 2005

A very useful summarize of the problematics concerning this topic

has been provided (eg, actual knowledges, actual related open questions…).

This summary highlights the strong need of the oceanic campains.

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Parallel Session : Ocean Atmosphere Coupling

2. Thematic discussions : 2) Air sea fluxes :

- Guy Caniaux (Météo-France/France) & Denis Bourras (CNRS/France): Air - Sea Flux analysis - Abderrahim Bentamy (IFREMER/France): Air - Sea Flux products :

- Erica Key (RSMAS /USA): Gulf of Guinea intensive aerosol network

=> Presentation of the EGEE 3 experiment motivations from in situ data, products and

model experiments : role of the sea surface fluxes and air sea interactions

⇒Presentation of available satellite derived products (fluxes, wind…)

⇒Confirmation that the Ron Brown cruise is scheduled but awaiting confirmation.

⇒

Confirmation that a large sampling of radiative, air moisture and gas is planed in the Gulf of

Guinea and off African coast during the SOP.

- measurements during EGEE 3 (skin temperature, by infrared radiometer ;

Marine

Marine--Atmospheric Emitted Radiance Interferometer MAtmospheric Emitted Radiance Interferometer M--AERI)AERI)

- installation of a long term (10 years) measurements station at Bioko (Equatorial Guinea)

for aerosol, clouds and radiation, planed in early 2006.

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Parallel Session : Ocean Atmosphere Coupling

2. Thematic discussions :

3) Ocean circulation in the Eastern Tropical Atlantic :

- Bernard Bourlès (IRD/France): Process studies (upwelling, cold tongue, equatorial currents system, waves) - Hervé Giordani (Météo-France): Numerical experiments & model validation :

=> Presentation of main studies in progress about ocean dynamic & processes :

- Currents and variability at 10°W from in situ measurements

- Termination of the eastward Equatorial Undercurrent in the Gulf of Guinea - Vertical mixing estimates from microstructure measurements

- Tropical instability waves (temperature fronts) analysis

⇒Presentation of numerical models hierarchy and strategy for their use :

from operational (MERCATOR), to mesoscale processes studies (ROMS)

⇒Presentation of a A 3D Simplified Oceanic Model Assimilating OGCM Currents

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Parallel Session : Ocean Atmosphere Coupling

2. Thematic discussions (introduced by presentations) 4) Air sea coupling :

- H. Giordani (Météo France) / D. Bourras (CNRS/France):

- Experimentation aspects (vessel / aircraft measurements <->TT8) - Numerical studies of atmospheric boundary layer:

⇒

Presentation of the marine atmospheric boundary layer associated to surface oceanic heterogeneities

(SST fronts associated to upwelling, cold tongue, Tropical Instability Waves…)

- Coupled measurements carried out during EGEE 3 cruise from the vessel and aircrafts

=> Presentation of numerical experiments for the study of the marine atmospheric boundary layer

associated to surface oceanic heterogeneities

- Unique opportunity to test and validate the AROME mesoscale numerical model

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Parallel Session : Ocean Atmosphere Coupling

3. Related programs/studies in Africa and links with EGEE/AMMA : 3.1 Littoral GG & coastal upwellings : A. Blivi + B.A.Sow +…

3.2 ODINAFRICA, CCLME, GCLME, BCLME… : A.Aman, R.Folorunsho, A. Blivi , B.A.Sow, R.Djiman, C.Reason… 3.3 Regional ARGO data center : R.Folorunsho / C.Reason

3.4 SST / Precipitation correlation studies : Y.Kouadio +…

3.5 Interaction and/or involvement in EGEE/AMMA (through CSAM) 3.6 Training & Capacity building

Adote Blivi (CGILE, TOGO):

ETAT DE RÉFÉRENCE DES CÔTES ET

ANALYSE DES DONNÉES MARÉGRAPHIQUES

POUR LE CONTRÔLE DE L’ELEVATION DU NIVEAU DE LA MER DANS LE GOLFE DU BÉNIN (AFRIQUE DE L’OUEST)

Presentation of main concerns in ocean studies by regional countries, ie:

- littoral environment

- coastal erosion

- coastal management

- data needs

No time availability to detail all of them, already partly discussed out of the parallel session)

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Parallel Session : Ocean Atmosphere Coupling

3. Related programs/studies in Africa and links with EGEE/AMMA :

This AMMA meeting was the only opportunity to gather some african oceanographers;

Thus, a first meeting has been held on Tuesday, that allowed to gather (for the 1st time) 13 peoples of different countries concerned by ocean studies (Nigeria, Benin, Togo, Ivory Coast, Senegal):

The suggestion to provide a document (deadline not defined yet, but 1st semester of 2006?) has been accepted by everybody, in order to do the inventory of:

- national programs and their potential link with / interest in / AMMA - their data needs

- national data sets, their description and availability.

The same information will be provided from the french side, as part of the french AMMA-EGEE program, that will be included in this document.

Motivation is to built a regional ocean data set that could be used for all the concerned studies, that could be considered as a main contribution to AMMA-Africa, through the CSAM.

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Parallel Session : Ocean Atmosphere Coupling

The clear wish of a close regional collaboration has been confirmed.

Main objectives and links between climatic studies (AMMA) and coastal and impact (coastal erosion, fisheries…) studies will be underlined in order to define a draft of a scientificdocument

(eg, winds variability versus coastal erosion variability, seasonal/interannual sea level variation…).

An official letter could then be sent to the responsible for the ODINAFRICA, CCLME, GCLME and BCLME programs in order to suggest (to invite to) a close collaboration with AMMA-EGEE and data sharing.

An e-mail list has been established.

Need for regional coordination funding!

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Parallel Session : Ocean Atmosphere Coupling

Other african concerns:

- Some coastal countries have the feeling that they stay on the side/border of the AMMA motivations, that appear more dedicated to Sahelian countries…

- eg, no impact studies on fisheries - no coastal dedicated studies

- numerical forecast models limited north of 5°N (eg ALADIN)

- About the data sets: one began an inventory of free access data or products that may be used by african oceanographers. Need of precise information on data policy about a few products:

- satellite (eg. Envisat…)

- analysis from specific numerical models (eg. ECMWF…) - ocean simulations (Mercator, …)

All these aspects and answers will be included in a ocean group document to be provided in 2006 to all the attendees.

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Parallel Session : Ocean Atmosphere Coupling

4. Data bases & satellite data : (? toward a dedicated regional data bank ?) 4.1 Ocean, atmosphere, fluxes in situ data

4.2 Products (sst, sss, sea surface color, ssh, winds, fluxes …) 4.3 Already available products,…

No time available to address these points. Only a few information about

A few data sets have been provided.

A meeting is however planed in Dec 15, 2005 in Lannion (France) in order

to begin an operational free web access to products of oceanic

and air-sea interactions parameters.

One goal is also to built a preliminary source of the best/adapted data

to feed the AMMA-Database.

eg: Flux climatologies

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Parallel Session : Ocean Atmosphere Coupling

5. Miscellaneous :

- About the Senegalese cruises planed in the Senegal AMMA program :

A final answer should be provided soon by AMMA-Senegal in order to know if these cruises are possible. -About the french Egee cruises in 2007:

- should be carried out onboard the IRD R.V ANTEA.

- a project to do the June 2007 cruise onboard the (larger) german Poseidon vessel is going on. -About an ARGO regional meeting (planed in 2006 or 2007 in Ghana, resp. R.Folorunsho –Nigeria-):

This meeting could be the opportunity 1) to involve the ocean African community (or to make it to collaborate) in ARGO and associated programs as AMMA; 2) to push for the need of a regional ocean data set.

-About training :

-During each EGEE or PIRATA cruises, scientists from interested/collaborating laboratories

(NIOMR/Nigera, LAPA/Ivory Coast, CRHOB/Benin, Univ.Lomé/Togo, LPA /Senegal) are invited -Organization within the ISSC:

It has been stated that very few exchanges exist between the continental surface-atmosphere community and the ocean surface-atmosphere community within the WG3. Actually, only the studies of the boundary layer seem to be more favorable to internal collaborations. A solution would be to split the WG3 in two groups:

WG3a: continental surface-atmosphere WG3b: ocean surface- atmosphere.