Plattform Platform	Reise-Nr. Cruise-No.	Zeitraum Period	Projekt Project	Arbeitsgebiet Working area
Maria S. Merian	MSM117	10.05.2023 - 15.06.2023		NW Atlantic (Limit 40?W) North Atlantic Ocean NE Atlantic (Limit 40?W)

Fahrtleiter Chief Scientist	Institut Institute	Auslaufhafen Port of departure	Einlaufhafen Port of return	Stationskarte Station map	Schiffsroute Trackchart
Hummels Rebecca	Helmholtz Centre for Ocean Research Kiel (GEOMAR)	Recife	Ponta Delgada

Ziel der Reise / Objectives of Cruise:

The objectives of R/V MARIA S. MERIAN cruise MSM117 were to investigate the variability of the western boundary current circulation off South America and to estimate the strength and variability of the Atlantic meridional overturning circulation (AMOC) at 11?S. A specific focus is on the transport variability of the North Brazilian Undercurrent (NBUC) as part of the AMOC and the Subtropical Cells (STCs) and the Deep Western Boundary Current (DWBC) on intraseasonal to decadal time scales. The meridional section along 35?W as well as the mooring maintenance at 23?W at the equator provides additional information with respect to signal propagation along and across the equator. These investigations also contribute to the EU project TRIATLAS ("Tropical and South Atlantic climate-based marine ecosystem predictions for sustainable management"), for which also additional measurements along the Brazilian shelf and over two submarine mountains were performed. Along the shelf and above the seamounts the focus was more on the interaction of the currents with the topography, the resulting biogeochemical conditions and ultimately the impact on the local ecosystem. The mooring of the Cape Verde Ocean Observatory (CVOO) is a central part of the cooperation between GEOMAR and Cape Verde within the activities around the Ocean Science Centre Mindelo (OSCM). A general goal of this observatory is a better understanding of the role of eddies in the ocean, especially with respect to the CO2 source/sink function and biological carbon pump in coastal upwelling areas. The main work during MSM117 was the recovery and deployment of four full-depth moorings at the Brazilian shelf, one mooring at 23?W at the equator and the CVOO mooring, CTD station work along the sections at 11?S, 5?S and 35?W, and the recovery and deployment of two inverted bottom echo sounders (PIES). For the station work, mainly the combination of CTD, Lowered ADCP and Underwater Vision Profiler (UVP) was used. In addition, currents and water mass properties was continuously measured with the shipboard ADCPs and the thermosalinograph. Along the Brazilian shelf and over the submarine mountains, the station work was complemented by microstructure and multinet measurements, the continuous underway measurements by a uCTD system.

Messungen / Measurements

Verankerungen / Moorings