RV Maria S. Merian MSM74

Cruise plan

Cruise Info. 
Ship name (ship code)RV Maria S. Merian (06M2)
Cruise identifierMSM74
Cruise period2018-05-25 — 2018-06-26
Port of departureSt. John's, Canada
Port of returnReykjavík, Iceland
ObjectivesThe North Atlantic Ocean is one of the most important drivers for the global ocean circulation and its variability on time scales beyond inter-annual. It could be shown that global climate variability is to a large extent triggered by changes in the North Atlantic sea surface state. The climate of Europe is strongly influenced by the North Atlantic ocean circulation, in particular the eastward transport of warm water with the North Atlantic Current has a strong impact on the mild winters in Northern Europe. The North Atlantic Current is to be seen as a connection between the warm, Subtropical Gyre and the cold, subpolar Gyre. A driver for the connection between the gyres, and as such for the North Atlantic Current, is the water mass transformation, and in particular the sinking of water, in the Northern North Atlantic - north of the Greenland-Scotland Ridges and in the Labrador and Irminger Seas. Intense cooling in winter make the surface water more dense and drives a sinking of the water. The water that has been transferred from surface to great depth spreads preferentially southward, concentrated in intense currents. Most prominent is the "Deep Western Boundary Currents" (DWBC) that transports water ventilated water masses in a well defined current southward. Beside the deep water formed in the Subpolar gyre, the DWBC transport water from the overflow regions southward. The strength as well as the characteristic of the DWBC is an indicator for the integral effect of time variability in the formation region of the water masses and the processes in the overflow region. As such it is critical to survey the DWBC regularly and over long periods of time to create time series of flow and properties to be able to decompose the variability of the DWBC on its different time scales.
The scientific program of the MARIA S. MERIAN MSM74 expedition is dedicated to the studies on the intensity of the water mass transformation and the southward transport in the DWBC. Moreover, measurement of the vertical structure (temperature, salinity, density, oxygen, optical properties and the flow) along selected sections will be carried during the MSM74 expedition. Close to the surface, permanent registrations are carried out with the thermosalinograph (temperature, salinity) and meteorological data are continuously collected. Flow measurements up to 1000m depth are performed with the ships installed ADCPs. The expedition is a contribution to national (RACE) and international projects (OSNAP, AtlantOS).
Chief scientistJohannes Karstensen (GEOMAR Helmholtz Centre for Ocean Research, Kiel (East Shore Campus))
ProjectUK - Overturning in the Subpolar North Atlantic Programme (UK-OSNAP)
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Physical oceanography 
CTD stationsQuantity: number of profiles = 115
Description: double T, double C, double O2, Chla
Current profiler (eg ADCP)Quantity: track kilometres = 3500
Description: ADCP 38kHz along track
Current profiler (eg ADCP)Quantity: track kilometres = 3500
Description: ADCP 75kHz along track
Chemical oceanography 
Other chemical oceanographic measurementsQuantity: number of samples = 100
Description: Nutrients: NO3, PO4, SiO3
Biology and fisheries 
Other biological/fisheries measurementQuantity: number of profiles = 115
Description: Underwater Vision Profiler
Moorings, landers, buoys 
Physical oceanography 
Other physical oceanographic measurements53° 15' 0" N  50° 32' 59" W — DSOW2 deploy
Other physical oceanographic measurements53° 1' 59" N  51° 4' 0" W — DSOW1 deploy
Other physical oceanographic measurements52° 49' 59" N  51° 32' 59" W — K7 deploy
Other physical oceanographic measurements52° 57' 0" N  51° 17' 59" W — K8 deploy
Other physical oceanographic measurements58° 37' 0" N  51° 52' 0" W — Argo float BGC
Other physical oceanographic measurements53° 22' 59" N  50° 7' 0" W — Argo float BGC
Other physical oceanographic measurements56° 34' 0" N  52° 38' 59" W — K1 deploy
Other physical oceanographic measurements60° 22' 0" N  48° 27' 0" W — lander
Other physical oceanographic measurements58° 37' 0" N  51° 52' 0" W — Argo float BGC
Other physical oceanographic measurements53° 7' 59" N  50° 52' 0" W — K9 deploy