The Cirene scientific cruise is scheduled for the January-February 2007 period, onboard the Suroît. It will involve two legs of about 20 days, both starting from the Seychelles.

The Cirene measurements are:

• Two ~12 day long stations in the vicinity of the TAO buoy will allow to gather intensive measurements of the upper ocean. The CTD will be operated continuously (profile every hour or more, including CTD, L-ADCP, fluorimeter, transmissiometer, PAR-sensor). Nutrients and chlorophyll measurements at some set levels will be performed 2 to 4 times per day. During these stations the ASIP instrument (B. Ward and T. Fristedt) will allow a detailed monitoring of uper 100m of the ocean (including the diurnal cycle within the top meter).

• Continuous air-sea fluxes measurements using the CETP/CNRM/DT INSU instrumented mast.

• Continuous atmospheric boundary layer and surface measurements using P. Minnett's team instrumental suite . See this document for a description of Cirene measurements.

• Continuous upper ocean currents and surface temperature and salinity measurements from the ship ADCP and thermosalinograph.

• 12 Argo profilers ( PROVOR type) will be deployed by groups of 3 along 67°E, at 3°S, 5°S, 7°S and 9°S. They will provide profiles every 5 days and each group of 3 is programmed to profile at ~2 days interval to provide increased temporal resolution over the first months after deployment (while they haven't yet drifted apart).

• 3 surface drifters (collaboration with B. Ward and R. Weller, plan here) with detailed temperature measurements down to 60m will allow to monitor the spatial heterogeneity in the mixed layer signal. A 1000m cable with an anchor will act as a drogue and prevent excessive drift.

• 2 to 4 radiosondes will be deployed everyday.

• 8 XBT casts will be done every day (except during the two long stations)

• one ATLAS buoy will be deployed at 67°E,8°S in collaboration with PMEL with enhanced measurements during the cruise (surface fluxes, salinity, currents by ADCP...). A scaled-down version (mostly temperature sensors and current-meters) will remain there after the cruise.

The figure below shows the SST at the ATLAS mooring location monitored by the TMI instrument on TRMM . It allows to verify that large SST events are indeed monitored almost every year at the cruise location (climatology: thin red line).