METEOR M98

The cruise M98 to the southern tropical Atlantic joins important field work of the BMBF project RACE and the BMBF project SACUS. Both projects have the overarching goal to gain better understanding for the role of the tropical Atlantic in relation to climate variability in the Atlantic region. According to the special issues within the subprojects this cruise has two major regional focuses:

Within the framework of RACE the aim of this cruise is to investigate the variability of the western boundary current system offshore of South America. A special focus will be laid on the transport variability of the North Brazil Undercurrent (NBUC) – as part of the meridional overturning circulation (AMOC) – on timescales from intraseasonal to decadal.

The project SACUS is concerned with the influence of the equatorial Atlantic on the upwelling region off Southwest Africa. This cruise aims at investigating these teleconnections from the equatorial region towards the upwelling system and their attributed time scales via wave propagation and water mass advection.

The substantial part of work for this cruise constitutes of the deployment of two mooring arrays at 11°S at shelf and continental slope off the Brazilian coast and off the Angolan coast. Additionally, the boundary current systems will be surveyed with two high-resolution, hydrographic sections (CTD/LADCP, microstructure) at 5°S and 11°S off Brazil and a hydrographic section at 11°S off Angola.
In addition, the flux of CO2 and Dimethylsulphide (DMS) between surface ocean and overlying atmosphere will be monitored continuously during the cruise.