Cruise 64PE400: Hydrographic survey of the Irminger Sea in July 2015 for the Overturning in the Subpolar North Atlantic Program (OSNAP)
|Temporal extent||2015-07-08 -2015-07-29|
|Author(s)||de Jong Marieke1, de Steur Laura2|
|Affiliation(s)||1 : NIOZ Royal Netherlands Institute for Sea Research and Utrecht University, Department of Ocean Systems (OCS), P.O. Box 59, 1790 AB Den Burg, Texel, the Netherlands
2 : Norwegian Polar Institute, Tromsø, Norway
|Note||This dataset includes the hydrographic CTD profiles only. Other data may be available on request.|
|Keyword(s)||CTD, Irminger Sea, hydrography, OSNAP, Pelagia, 64PE400|
During cruise 64PE400 the OSNAP East moorings, which were deployed in the Irminger Basin in summer 2014 have been recovered, serviced and redeployed. There are 5 moorings in the eastern Irminger Sea in the Irminger Current (IC) maintained by NIOZ, 5 moorings in the Western Irminger Sea in the Deep Western Boundary Current (DWBC) maintained by NOC, and one mooring (LOCO2) in the centre of the Irminger gyre (section 4) maintained by NIOZ. A total of 34 RAFOS floats were released at target depths between 1800 and 2200 m in the eastern and western Irminger Sea as part of the US OSNAP program (see cruise report). The mooring work was complemented with repeat CTD stations on the former WOCE (or current CLIVAR) AR7E repeat section (between roughly 59°N, 31°W and 60°N, 42.5°W) including sampling for salinity and dissolved oxygen (O2) calibration. On the westernmost CTD stations in the East Greenland Current samples for ∂18O and nutrients were also taken.A second short CTD section was carried out on the Greenland shelf slope at approximately 64.5°N.
|Acknowledgements||This work was funded by the NACLIM project, financed by the European Commission through the 7th Framework Programme for research Grant Agreement 308299.|
A recently (April 2015) calibrated SBE 9/11+ CTD, SN-0942, was used to measure temperature, salinity, and turbidity profiles. The sensors mounted on the CTD were an SBE3 temperature sensor SN-001219, SBE4 conductivity sensor SN-003262, a Digiquatz pressure sensor SN-127486, an SBE43 oxygen sensor SN-0431932, a Wetlab CStar beam transmission meter SN-CST-1406DR with a path length of 25 cm, a Chelsea PAR/irradiance sensor SN-118, and a Chelsea Aqua 3 fluorometer SN-088008. The CTD was mounted in a special rack, which contained 22 Niskin water samplers. Two Niskin water samplers were taken off the rosette to make space for the dual-head LADCP set up (Lowered Acoustic Doppler Current profiler). To control the temperature measurements an SBE35 Deep Ocean Standards thermometer was mounted next to the temperature sensor of the CTD. Reference temperature samples were taken with this when water samples were taken with the Niskin samplers. At every bottle stop the CTD operator waited one minute to allow the bottle to be flushed properly. After the bottle was closed another minute was waited to allow the SBE35 to register temperature. The water from these samplers was sub-sampled for the determination of dissolved oxygen and salinity on most stations and for nutrients and δO18 on the stations near Greenland.