Subpolar gyre variability, Cruise No. MSM54, May 12 - June 04, 2016, St. John's (Canada) - Reykjavik (Iceland) (English)

The core working program of the Maria S. Merian expedition MSM54 was dedicated to the re-deployment of moored instrumentation and the acquisition of data from the water column in the Labrador and Irminger Sea regions. Moored instrumentation, programed for high temporal resolution sampling (<1 hour) and installed at distinct locations in the Labrador and Irminger Seas, determine the local evolution of physical properties (temperature, salinity, density, currents). Continuous installations of such system over many years provide the observational base for the analysis of systematic dynamical and hydrographic variability and eventually long term changes of the interior ocean. In a global context only a few of such long lasting ocean- reference-stations exists. Along selected sections the hydrographic (temperature, salinity, density), oxygen, and currents structure was determined using data from CTD/O2/(l)ADCP systems. These systems operate over the full water depth, from the surface to the ocean bottom. Moreover, quasi-continuous underway data collection was performed using the Thermosalinograph (Temperature, Salinity), and surface meteorological observations, but also ship mounted ADCP systems (currents in upper 500 to 1000m). The cruise contributed to the investigations that are done in the national RACE program, and in the international NACLIM (EU) and AtlantOS (EU) projects, and the OSNAP and VITALS initiatives.