Cruise inventory

RRS Discovery DY052

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74EQ)
Cruise identifierDY052
Cruise period2016-06-07 — 2016-06-24
StatusCompleted
Port of departureGreenock, United Kingdom
Port of returnGreenock, United Kingdom
PurposeResearch
ObjectivesThe Extended Ellett Line is a hydrographic section between Iceland and Scotland that is occupied annually by scientists from the National Oceanography Centre (NOC) and the Scottish Association for Marine Science (SAMS), UK.
The measurement programme began as a seasonally-occupied hydrographic section in the Rockall Trough in 1975, building on early surface observations made underway from ocean weather ships.
In 1996 the section was extended to Iceland, sampling three basins: the Rockall Trough, the Hatton-Rockall Basin and the Iceland Basin. These three basins form the main routes though which warm saline Atlantic water flows northwards into the Nordic Seas and Arctic Ocean. The section crosses the eastern North Atlantic subpolar gyre; as well as the net northward flow there is a large recirculation of the upper layers as part of the wind-driven gyre.
During its passage through the region, the warm saline water is subjected to significant modification by exchange of heat and freshwater with the atmosphere. The two deep basins (Rockall Trough and Iceland Basin) contain southward flowing dense northern overflow waters, and Labrador Sea Water in the intermediate layers.
The specific objectives of the 2016 Extended Ellett Line cruise are:
- To complete the annual Extended Ellett Line CTD section;
- To collect water samples for measuring biogeochemical properties including dissolved oxygen, nutrients, carbon & trace metals;
- To collect underway measurements of surface currents, surface temperature and salinity, bathymetry, surface meteorology;
- To complete epibenthic sled tows at a deep location in the central Rockall Trough;
- To capture water column and sea floor video with a downward-looking camera attached to the CTD;
- To listen for whales and dolphins with a towed hydrophone; and
- To deploy Argo floats provided by the UK Met Office as a contribution to the International Argo Project.
Chief scientistStefan F Gary (Scottish Association for Marine Science)
ProjectExtended Ellett Line
Cruise reportRRS Discovery DY052 cruise report dy052.pdf — access key 'C' (7.97 MB) 
Ocean/sea areas 
GeneralNorth East Atlantic Ocean (limit 40W)
SpecificRockall Trough, Hatton-Rockall Basin, Iceland Basin.
Track chartsRRS Discovery DY052 cruise track — dy052trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 17
Description: Discrete salinity samples taken from underway system intake. Measured on board.
Surface measurements underway (T,S)Quantity: activity duration in days = 17
Description: Underway thermosalinograph measurements of sea surface temperature, conductivity, transmittance and fluorescence.
Water bottle stationsQuantity: number of stations = 89
Description: Niskin samples
CTD stationsQuantity: number of stations = 89
Description: CTD stations - Standard SBE9/11+ CTD package
Current profiler (eg ADCP)Quantity: activity duration in days = 17
Description: VMADCP - Underway ADCP measurements - 75 kHz system and 150 kHz system
Current profiler (eg ADCP)Quantity: number of stations = 89
Description: LADCP - upward looking 300 kHz system
Other physical oceanographic measurementsQuantity: number of stations = 9
Description: Density samples
Chemical oceanography 
OxygenQuantity: number of stations = 89
Description: Oxygen samples
Other dissolved gasesQuantity: number of stations = 9
Description: Dissolved inorganic Carbon
PhosphateQuantity: number of stations = 89
Description: Phosphate
Total - NQuantity: number of stations = 89
Description: Total Nitrogen
SilicateQuantity: number of stations = 89
Description: Silicate
IsotopesQuantity: number of stations = 4
Description: Nd isotopes
Other chemical oceanographic measurementsQuantity: number of stations = 89
Description: Salinity Samples
Contamination 
Trace metalsQuantity: number of stations = 9
Description: Trace Metals
Biology and fisheries 
Acoustic reflection on marine organisms.Quantity: number of hauls = 47
Description: Towed Hydrophone
Exploratory fishingQuantity: activity duration in days = 9
Description: EK60 fish finder
Other biological/fisheries measurementQuantity: number of hauls = 4
Description: Benthic Sled
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 17
Description: Underway meteorology measurements of radiation, air temperature, wind speed and direction, relative humidity and air pressure.
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 17
Description: Single beam Echo
Multi-beam echosoundingQuantity: activity duration in days = 17
Description: Multi beam Echo
Moorings, landers, buoys 
Physical oceanography 
Neutrally buoyant floats61° 0' 0" N  20° 0' 0" W — Argo float SN 7575
Neutrally buoyant floats61° 0' 0" N  20° 0' 0" W — Argo float SN 7576
Neutrally buoyant floats61° 0' 0" N  19° 58' 59" W — Argo float SN 7626
Other physical oceanographic measurements60° 12' 0" N  18° 16' 59" W — Recovery of Seaglider Eltanin