Cruise inventory

RRS Discovery DY040

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74EQ)
Cruise identifierDY040
Cruise period2015-12-06 — 2016-01-22
StatusCompleted
Port of departureNassau, Bahamas
Port of returnLas Palmas, Spain
PurposeResearch
ObjectivesThis cruise was a UK contribution to GO-SHIP. The plan was to occupy full-depth CTD stations on the line designated in WOCE/CLIVAR/GO-SHIP planning as A05.

The sampling was full depth measurements of physical parameters by Conductivity-Temperature-Depth (CTD) package, with water sampling for a variety of tracers including oxygen, nutrients, inorganic carbon and CFCs. The data are contributions to a number of NERC projects ('RAGNARoCC' and 'RAPID') and to international projects including GO-SHIP/IOCCP repeat hydrography program.

Climate change will be studied by comparing the new data with historical measurements. Ocean heat transport plays a major role in the coupled ocean-atmosphere climate system. We will study the present-day circulation by calculating the heat and freshwater transported by the ocean across the 24.5N latitude. The ocean western boundary current system, in this case the circulation in the Florida Strait, plays a crucial role in the oceanic heat transport. Therefore we undertook two crossings of the Florida Strait.
Chief scientistBrian A King (National Oceanography Centre, Southampton)
ProjectRAGNARoCC; RAPID; GO-SHIP/Carbon repeat hydrography program
Coordinating bodyNatural Environment Research Council (NERC)
Ocean/sea areas 
GeneralNorth Atlantic Ocean
SpecificTransect across Atlantic at 24N
Track chartsRRS Discovery DY040 cruise track — dy040trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: number of samples = 250
Description: Discrete water samples collected from non-toxic supply to calibrate underway salinity sensor. Analysed using an autosalinometer standardized with a sea water standard.
Surface measurements underway (T,S)Quantity: activity duration in days = 45
Description: Underway pumped seawater carbon parameters. Parameters: pCO2
Surface measurements underway (T,S)Quantity: activity duration in days = 45
Description: Underway pumped seawater physical parameters. Parameters: salinity, temperature, beam transmission, fluorescence
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to calibrate CTD oxygen sensor. Analysed using a dissolved oxygen analyser with automatic end-point detection.
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to calibrate CTD conductivity sensor. Analysed using an autosalinometer standardized with a sea water standard.
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine carbon parameters (DIC, TA)
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles for transient tracer analysis; CFC11; CFC12; CFC113; SF6
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine methane and nitrous oxide
Water bottle stationsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine inorganic nutrient concentration. Analysed with segmented flow autoanalyser and colourimetric detection.
CTD stationsQuantity: number of stations = 145
Description: SeaBird 9/11. 234 CTD casts total. Parameters: temperature, salinity, pressure, oxygen, fluorescence, beam transmission, PAR. altimeter, water velocities
Current profiler (eg ADCP)Quantity: activity duration in days = 45
Description: 75kHz vessel-mounted ADCP surveys
Chemical oceanography 
OxygenQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to calibrate CTD oxygen sensor. Analysed using a dissolved oxygen analyser with automatic end-point detection.
Carbon dioxideQuantity: activity duration in days = 45
Description: Underway pumped seawater carbon parameters. Parameters: pCO2
Carbon dioxideQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine carbon parameters (DIC, TA)
PhosphateQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine inorganic nutrient concentration. Analysed with segmented flow autoanalyser and colourimetric detection.
NitrateQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine inorganic nutrient concentration. Analysed with segmented flow autoanalyser and colourimetric detection.
NitriteQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine inorganic nutrient concentration. Analysed with segmented flow autoanalyser and colourimetric detection.
SilicateQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine inorganic nutrient concentration. Analysed with segmented flow autoanalyser and colourimetric detection.
AlkalinityQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine carbon parameters (DIC, TA)
AlkalinityQuantity: activity duration in days = 45
Description: Underway pumped seawater carbon parameters. Parameters: pCO2
pHQuantity: activity duration in days = 45
Description: Underway pumped seawater carbon parameters. Parameters: pCO2
Other chemical oceanographic measurementsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles for transient tracer analysis; CFC11; CFC12; CFC113; SF6
Other chemical oceanographic measurementsQuantity: number of stations = 145
Description: Discrete water samples collected from CTD bottles to determine methane and nitrous oxide
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 45
Description: Underway Meteorology. Parameters: air temperature, air humidity, wind speed, wind direction, atmospheric pressure, TIR, PAR
Moorings, landers, buoys 
Physical oceanography 
Neutrally buoyant floats24° 30' 0" N  65° 0' 0" W — 6 Argo floats deployed to be freely drifting in the North Atlantic
Neutrally buoyant floats24° 30' 0" N  30° 0' 0" W — 2 Argo floats deployed to be freely drifting in the North Atlantic
Neutrally buoyant floats24° 30' 0" N  40° 0' 0" W — 2 Argo floats deployed to be freely drifting in the North Atlantic
Neutrally buoyant floats24° 30' 0" N  55° 0' 0" W — 3 Argo floats deployed to be freely drifting in the North Atlantic