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The CIRENE oceanographic campaign, within the west Indian Ocean will be synchronized with the VASCO observing system (Aeroclippers and pressurized balloons launched from the Seychelles). During CIRENE, physical oceanography, air-sea fluxes and atmospheric measurements will be collected and a special care will be taken in measuring the diurnal cycle in the surface layer since it is believed to play an important role in intraseasonal SST variability. Biogeochemical measurements (nutrients, pigments) will also be collected because they can provide useful information on the physical processes at the origin of the SST perturbation. These measurements will be combined with those from VASCO and from Provor/Argo floats.

General view of the Vasco-Cirene campaign
vasco cirene campaign
During the Vasco-Cirene experiment Aeroclippers and pressurized baloons (pictures below) will be deployed from the Seychelles and will sample the region of the Cirene campaign. An ATLAS mooring will be deployed at 67°E, 8°S during Cirene and the Suroit ship will be located at 8°S-67°E. The background indicates the level of intraseasonal SST variability in winter.

The Vasco balloons
aeroclipper and BPCL
An aeroclipper (left) and a pressurised balloon (right). The pressurised balloon measures temperature, humidity and pressure close to the top of the boundary layer. The aeroclipper is a new system that takes atmospheric measurements (wind, temperature, humidity, pressure) ~30m above the surface and sea surface measurements (temperature and salinity). This makes it possible to estimate turbulent heat ans water vapour air-sea fluxes along its trajectory using bulk formulae.

The two legs of the Cirene Campaign
the cirene legs
Planned trajectories of the Suroît during the two legs of the Cirene campaign in January-February 2007. Both legs last ~20 days and start and return to the Seychelles. During Cirene, one ATLAS buoy will be deployed at 67°E,8°S in collaboration with PMEL with enhanced measurements during the campaign (surface fluxes, salinity, currents by ADCP...). A scaled-down version (mostly temperature sensors and current-meters) will remain there after the campaign. 12 Provor Argo floats will be deployed  as well as three surface drifters (collaboration with WHOI). The detailed evolution of the upper ocean will be measured using ASIP and by CTD during two 12-day stations close to the ATLAS mooring. The surface fluxes will be measured continuously using the CETP/CNRM/DT INSU instrumented mast. 2 two 4 radiosondes will be deployed everyday and several boundary layer and atmospheric measurements will be done continuously in collaboration with RSMAS. Biogeochemical measurements (nutrients and pigments) will also be collected.

The Vasco-Cirene Campaign