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C01 and C02-moorings in the Sicily Channel (WMO IDs: 6101021 and 6101022)

SUMMARY

 

A system consisting of two underwater stations at depths of 450 m and 530 m, respectively, moored between Sicily and Tunisia, off the wide continental shelf at the western sill of the Sicily Channel. They are operative since 1993, and are dedicated to long term monitoring of surface and intermediate circulation and water exchanges between the eastern and western Mediterranean basins. The sites are also part of the CIESM Hydrochanges Programme and participated in the JERICO projects transnational access activities.

GENERAL INFORMATION
 

C01
Location: Sicily Channel (37.380° N, 11.591° E)
Distance from land: 31 nm from Tunisia, 46 nm from Sicily
Max water depth: 450 m
Date 1st deployment: 11/11/1993
Supported by: Italy
Operated by: CNR ISMAR
Website: http://www.ismar.cnr.it/infrastructures/observational-systems/moorings/il-canale-di-sicilia?set_language=en&cl=en
Status: running

C02
Location: Sicily Channel (37.285° N, 11.5° E)
Distance from land: 25 nm from Tunisia, 52 nm from Sicily
Max water depth: 530 m
Date 1st deployment: 09/11/1993
Supported by: Italy
Operated by: CNR ISMAR
Website: http://www.ismar.cnr.it/infrastructures/observational-systems/moorings/il-canale-di-sicilia?set_language=en&cl=en (data are available at: ftp://nrt.cmems-du.eu/Core/INSITU_MED_NRT_OBSERVATIONS_013_035/med_multiparameter_nrt/history/MO/MO_TS_MO_6101022.nc)
Status: running
 

SCIENTIFIC OBJECTIVES

The Sicily Channel separates the Mediterranean Sea into its two basins, the Eastern and the Mediterranean, and it is the most important Mediterranean passage after Gibraltar. As at Gibraltar, there is a two-layer system that is maintained by the excess of evaporation over the EMED. Its monitoring is fundamental for the quantification of the highly variable exchanges between the two basins, particularly with regard to heat and salt fluxes. The monitoring of the bottom layer in both trenches regards the Levantine (and Cretan) Intermediate Waters (LIW/CIW) and the upper part of the deep waters of eastern origin. The lower part of the Atlantic Water (AW) flowing eastward is also captured, before partly overflowing into the Tyrrhenian Sea through the Sicily Channel.

DESCRIPTION OF THE INFRASTRUCTURE
 

Between Cape Bon (Tunisia) and Mazara del Vallo (Italy), a ridge divides the channel longitudinally into two trenches each with very different cross-sectional areas. The axis of the Sicilian trench and adjacent to the wide Sicilian plateau is directed northwards, is very narrow, and has a maximum depth of 450 m (mooring C01). The Tunisian trench is wider, deeper, and with a sill depth at about 530 m (mooring C02). The present basic configuration of both moorings sees an upward looking ADCP (RDI Longranger 75 kHz) near the bottom, that profiles the currents of the whole water column, and 2-3 CTD probes (SBE37-SM) at different depths, measuring temperature, salinity and pressure within the two water masses, AW and LIW/CIW.
Over the years, a number of additional probes have been added for limited time periods, in the framework of specific experiments (such as pCO2, O2, turbidity, profiling CTD).
Maintenance and data recovery are managed twice per year. Data are available only in delayed mode.