EGITTO Project


EGITTO is an observational program to study the circulation in the southeastern Mediterranean Sea and to confirm (or not) the various circulation patterns published in the literature based on in-situ observations, remote sensing data and models. The near-surface circulation eddy and seasonal variabilities are described with low-cost satellite-tracked drifters in concert with satellite observations of sea surface temperature, near -surface chlorophyll pigment concentration and sea surface dynamic topography.

The main focus is on the Atlantic Water main pathways that have recently been represented as coastal and along-slope currents off the African coast and that are extremely unstable and generate energetic meanders and anticyclonic eddy circulation features.

In straight collaboration with French oceanographers and local Tunisian and Egyptian scientists, the surface circulation in the southeastern Mediterranean Sea is monitored for about a year with drifters released in the Strait of Sicily and off eastern Egypt on a seasonal basis. Eulerian (seasonal maps of mean currents and eddy variability) and Lagrangian (one and two-particle diffusion) statistics are computed. Satellite data are integrated with the drifter observations to study the circulation variations and their relations to the local wind forcing and the bottom topography.


The main objective of EGITTO is to improve the understanding of marine environmental evolution, with particular emphasis on the eddy dynamics in marginal seas where the effect of bottom morphology, the forcing by sheared winds and fresh water inflow can be significant factors.

It is obvious from the literature that the southeastern Mediterranean circulation is highly variable at eddy, seasonal and interannual scales, and that historical observations have provided only partial, inadequate, and even controversial descriptions due principally to the scarcity (and low quality) of in-situ observations. In conjunction with investigations proposed by French, Tunisian and Egyptian colleagues (including hydrographic surveys, moorings, surface drifters) a drifter experiment is conducted to elucidate the circulation patterns and to study the Atlantic Water pathways, including the Lybio-Egyptian Current and associated eddy instabilities.

More specifically, the study of the southeastern Mediterranean near-surface circulation variability over an entire year using Lagrangian drifters and satellite products include the following activities:
  • Perform an extensive review of existing knowledge on the circulation of the southeastern Mediterranean Sea.

  • Describe the surface circulation variability (Eulerian and La grangian statistics, major scales of variability, particle dispersion, etc.) and separate this variability into mean (over a year) , seasonal (3 months), wind-related (split in wind regimes), synoptic (~10 days) and mesoscale (a few days).

  • Describe the s patial structure and temporal variability of predominant eddy circulation features, such as the Mersa-Matruh and Shikmona Gyres in the southern Levantine sub-basin.

  • Relate the surface circulation characteristics derived from the drifter data to the thermal and pigment signatures observed from satellites.

  • Study the effect of wind forcing (e.g., the Etesians) and bathymetry on the surface circulation.

  • Combine concurrent drifter and satellite altimetry data and model simulations to construct accurate maps of mean absolute near-surface geostrophic currents.


The EGITTO project is organized into the following tasks:

Task 1: Review of circulation

Task 2: Drifter procurement and deployments

Task 3: Data management

  • Subtask 3.1: Near-real time during TOP
  • Subtask 3.2: Database (after TOP)
Task 4: Data analyses
  • Subtask 4.1: Surface velocity statistics
  • Subtask 4.2: Comparison and combination of drifter, remote sensing observations and ancillary data
  • Subtask 4.3: Construction of synthetic mean surface dynamic topography maps.


Consiglio Nazionale delle Ricerche (CNR), Italy

Drs. M. Astraldi and G. Gaspararini of CNR-ISMAR in La Spezia ( and

Dr. F. Fiorentino of CNR-IAMC in Mazara del Vallo (Sicily) (

Dr. M.-H. Rio of CNR-ISAC in Rome (

Ente per le Nuove tecnologie, l'Energia e l'Ambiente (ENEA), La Spezia, Italy

Dr. G. Manzella (

Laboratoire d'Oceanographie et de Biogeochimie (LOB), La Seyne, France

Dr. C. Millot (

Dr. I. Taupier-Letage (

Collecte Localisation Satellites (CLS), Toulouse, France

Dr. P.-Y. Le Traon (

Dr. G. Larnicol (

Institut National des Sciences et Technologies de la Mer (INSTM), Salammbô, Tunisia

Dr. C. Sammari (

Ms. Sana Ben Ismail (

National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt

Dr. M. A. Said (

Alexandria University Department of Oceanography (AUDO), Alexandria, Egypt

Dr. A. El-Gindy (om:

NAVOCEANO - Naval Oceanographic Office, Stennis Space Center, Bay St Louis, Mississippi

Dr. C. Horton (


Gerin R. & P.M. Poulain (2005)
Hydrographic structures and circulation outline of the southeastern Mediterranean off the Egyptian coast. OGS Tech. Report 42/2005 - OGA/23, OGS, Trieste, Italy. (pdf file)

Poulain, P.M., I. Taupier-Letage, R. Gerin and G. Notarstefano (2006)
Oceanographic Cruise EGITTO-1 R/V OGS - EXPLORA 11-18 November 2005 Trieste, Italy to Port Said, Egypt. Cruise Report. OGS Tech. Report 29/2006 - OGA/14, OGS, Trieste, Italy. (pdf file)


Alhammoud B., K. Beranger, L. Mortier, M. Crepon, and I. Dekeyser (2004) Surface circulation of the Levantine Basin: comparison of model results with observations. Prog. Oceanogr., accepted.

Ayoub, N., P. Le Traon and P. De Mey (1998) A description of the Mediterranean surface variable circulation from combined ERS-1 and TOPEX/POSEIDON altimetric data. J. Mar. Sys., 18, 3-40.

Halim, Y. (1990) On the potential migration of Indo-Pacific plankton through the Suez Canal. Bulletin de l?Institut Océanographique, Monaco, no spécial, 7, 11-27.

Hamad N., C. Millot and I. Taupier-Letage (2004) The surface circulation in the eastern basin of the Mediterranean Sea. Prog. Oceanogr., in press.

Hansen, D. V. and P.-M. Poulain (1996) Processing of WOCE/TOGA drifter data. J. Atmos. Ocean. Tech., 13, 900-909.

Korres, G. and A. Lascaratos (2003) A one-way nested eddy resolving model of the Aegean and Levantine basins: implementation and climatological runs. Ann. Geophys., 21, 205-220.

Lacombe, H. and P. Tchernia (1972) Caractères hydrologiques et circulation des eaux en Mediterranee. Mediterranean Sea, D. Stanley ed., Dowden, Hutchinson and Ross, Stroudsburg, 25-36.

Larnicol, G., N. Ayoub and P.-Y. Le Traon (2002) Major changes in Mediterranean Sea level variability from 7 years of TOPEX/POSEIDON and ERS-1/2 data. J. Mar. Sys. 33-34, 63-89.

Malanotte-Rizzoli, P., B. Manca, M. Ribera D'Alcala, A. Theocharis, A. Bergamasco, D. Bregant, G. Budillon, G. Civitarese, D. Georgopoulos, A. Michelato, E. Sansone, P. Scarazzato and E. Souvermezoglou (1997) A synthesis of the Ionian Sea hydrography, circulation and water mass pathways during POEM-Phase I. Prog. Oceanogr. 39, 153-204.

Matteoda, A. and S. M. Glenn (1996) Observations of recurrent mesoscale eddies in the eastern Mediterranean. J. Geophys. Res., 101(C9), 20687-20709.

Mauerhan, T. (2000) Drifter observations of the Mediterranean Sea surface circulation. Master Thesis, Naval Postgraduate School, Monterey, CA, p.114.

Millot, C. (1999) Circulation in the Western Mediterranean sea. J. Mar. Sys., 20, 423-442.

Millot, C. and I. Taupier-Letage (2004) Circulation in the Mediterrean Sea. The Handbook of Environmental Chemistry, Vol. 1 (The Natural Environment and the Biological Cycles), Springer-Verlag Editor, in press.

Nielsen, J. N. (1912) Hydrography of the Mediterranean and adjacent waters. Rep. Dan. Oceanogr. Exp. Medit., 1, 77-192.

Onken, R. and J. Sellschopp (1998) Seasonal variability of flow instabilities in the Sicily Strait. J . Geophys. Res.,103(C11), 24799-24820.

Ovchinnikov, I. M. (1966) Circulation in the surface and intermediate layers of the Mediterranean, Oceanology, 6, 48-59.

Ozsoy, E., A. Hecht, U. Unluata, S. Brenner, H. I. Sur, J. Bishop, M. A. Latif, Z. Rozentraub and T. Oguz (1993) A synthesis of the Levantine Basin circulation and hydrography 1985-1990. Deep Sea Res., 40, 1075-1119.

Pinardi, N. and A. Navarra (1993) Baroclinic wind adjustment processes in the Mediterranean Sea. Deep Sea Res. (Part II), 40, 129-1326.

Pinardi, N., G. Korres, A. Lascaratos, V. Roussenov and E. Stanev (1997) A seasonal model of the Mediterranean Sea general circulation. Geophys. Res. Lett., 24, 425-428.

POEM Group (1992) General circulation of the Mediterranean Sea. Earth Sci. Rev., 32, 285-309.

Poulain, P.-M. and P. P. Niiler (1989) Statistical analysis of the surface circulation in the California Current System using satellite-tracked drifters. J. Phys. Oceanogr, 19, 1588-1603.

Poulain, P.-M., A. Warn-Varnas and P. P. Niiler (1996) Near-surface circulation of the Iceland-Norwegian s eas as measured by Lagrangian drifters. J. Geophys. Res., 101(C8), 18237-18258.

Poulain, P.-M. (2001) Adriatic Sea Surface Circulation as derived from drifter data between 1990 and 1999. J. Mar. Sys., 29, 3-32. Poulain, P.-M., E. Mauri and L. Ursella (2004) Unusual upwelling event and current reversal off the Italian Adriatic coast in summer 2003. Geophys. Res. Lett., Vol. 31, L05303, doi:10.1029/2003GL019121.

Rio, M.-H. (2003) A mean dynamic topography computer over the world ocean from altimetric, gravimetric and in-situ data. Ph.D thesis, Uni. Paul Sabatier, Toulouse, France.

Rio, M.-H., P.-M. Poulain, A. Pascual and E. Mauri (2004) A mean dynamic topography on the Mediterranean sea computed from Altimetry data and in-situ measurements. J. Mar. Sys., in preparation.

Robinson, A. R., M. Golnaraghi, W. G. Leslie, A. Artegiani, A. Hecht, E. Lazzoni, A. Michelato, E. Sansone, A. Theocharis and U. Unluata (1991) The Eastern Mediterranean general circulation: features, structure and variability. Dyn. Atm. Oceans, 15, 215-240.

Robinson, A. R. and M. Golnaraghi (1993) Circulation and dynamics of the Eastern Mediterranean Sea; Quasi-Synoptic data-driven simulations. Deep Sea Res., 40 (6), 1207-1246.

Robinson, A. R. and M. Golnaraghi (1994) The physical and dynamical oceanography of the Mediterranean. In Ocean Processes in Climate Dynamics: Global and Mediterranean Examples. P. Malanotte-Rizzoli and A. R. Robinson (eds.), Kluwer Academic Publishers, The Netherlands, 255-306.

Roussenov, V., E. Stanev, V. Artale and N. Pinardi (1995) A seasonal model of the Mediterranean Sea general circulation. J. Geophys. Res., 100(C7), 13515-13538.

Tziperman, E. and P. Malanotte-Rizzoli (1991) The climatological seasonal circulation of the Mediterranean Sea. J. Mar. Res., 49, 411-434.
For more information please contact P.-M. Poulain or R. Gerin.