The Oceanic Cruises

The oceanographic observations of AMMA will support the land and atmospheric measurements during the three observing periods LOP, EOP, and SOP.

They aim to provide needed measurements for:

• the study of processes that determine seasonal to interannual variability of observed sea surface temperature (SST), sea surface salinity (SSS), mixed layer depth and heat content, in the Tropical Atlantic and in the Gulf of Guinea, and their linkage with West African land surface conditions;
• the study of processes that determine the seasonal evolution of the cold tongue - Inter Tropical Convergence Zone (ITCZ) - West African Monsoon (WAM) system.
• the study of both ocean and atmosphere boundary layers and air-sea exchanges;
• the validation of models, satellite data and products.
  

For more information: TT6-document Oceanic campaigns and measurements from open Ocean (EOP and SOP) (April 2006, pdf, size 1.37 Mb)

EOP/SOP French cruises

In order to assess interannual and seasonal variability, six EGEE cruises in the Gulf of Guinea (GG) are planed in the framework of AMMA-France, with two cruises per year scheduled during the three EOP AMMA years (2005-2007). In order to sample the GG during contrasting climatic situations, the cruises will be carried out in boreal spring-summer (monsoon setting, in phase with the equatorial upwelling onset, i.e. around end of May to July), and boreal fall (late monsoon, end of equatorial upwelling, the Inter-Tropical Convergence Zone (ITCZ) going back to its southernmost position, i.e. around September-October). The repetition of the cruises during these two opposite seasons during all three years will allow assessment of seasonal and interannual variability. To achieve this objective, the same tracklines will be repeated with particular attention directed at the 10°W meridional section, which has been occupied several times during previous PIRATA and EQUALANT cruises.

The EGEE cruises with different Research Vessels (R/V)

2005

EGEE 1 with the R/V LE SUROIT from June 6th to July 4th and EGEE 2 with the R/V SUROIT from September 3rd to October 1st

2006

EGEE 3 with the R/V ATALANTE from May 25th to July 7th (Official log book) (AMMA log book)

 

SOP1 US cruise (with implications for EOP and LOP cruises)

During this cruise, in addition to classical current and hydrological measurements in the upper ocean layers, 2 ATLAS buoys will be deployed at positions along 23°W to be determined. In addition, surface drifters (all equipped with SST sensors and some with wind and atmospheric pressure sensors) and ARGO profilers will be deployed. Support will also be requested for two other ATLAS moorings to be deployed in 2007 (i.e., implying yearly cruises to the region to maintain the ATLAS buoys). These ATLAS buoys along with the ones located along 10°E will collect data in both the ocean and atmosphere boundary layers and the variability on both sides of the ITCZ during all the phases of the WAM.

The US AMMA cruise

2006

US AMMA cruise with the R/V Ron Brown from May to June

SOP1 German Cruise

A German cruise by IFM-GEOMAR with R/V METEOR is funded and scheduled from June 6 - July 9 2006, in the framework of a German CLIVAR-TACE contribution. Main part of this cruise will be the deployment of a current meter mooring array consisting of 5 moorings near 23°W at the equator as well as intensive microstructure measurements in the equatorial region. The observations will provide estimates of transport and water mass variability of the flow toward the eastern upwelling regions (cold tongue) and to document intraseasonal, seasonal and interannual variability in the central equatorial Atlantic. During the cruise twice-daily radio-soundings will be performed. The cruise will also be used to deploy ARGO profilers from the German ARGO program

The German cruise

2006

German cruise with the R/V METEOR from June 6th to July 9th

SOP Senegalese Cruises

Several 5-day cruises are proposed in the framework of the oceanographic component of the AMMA-Senegal project. These cruises could be conducted using the R/V ITAF-DEME of CRODT/ISRA, in collaboration with the French AMMA/EGEE program. The French program would partly found the vessel chartering. Three cruises are planed at about one month interval from Dakar to Cap-Vert to survey the ocean boundary layer with CTD and XBT profiles, and could be also opportunities for surface drifter and profiler deployments.