Resources

RRS James Cook JC174 (JC175)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Cook (740H)
Cruise identifierJC174 (JC175)
Cruise period2018-10-20 — 2018-11-26
StatusCompleted
Port of departureLas Palmas, Spain
Port of returnFreeport, Bahamas
PurposeResearch
ObjectivesThe primary purpose of the cruise was to service the UK contribution to the RAPID-MOC/MOCHA mooring array.

The RAPID-MOC/MOCHA array was first deployed in 2004 to measure the Atlantic Meridional Overturning Circulation (AMOC) at 26°N and has been maintained by regular service cruises since then. The servicing and redeployment of the UK moorings on this cruise are conducted under the RAPID-AMOC programme. RAPID-AMOC continues the measurements at 26°N and extends these to include biological and chemical measurements in order to determine the variability of the AMOC and its links to climate and the ocean carbon sink on interannual-to-decadal time scales. The ABC Fluxes project is also funded under RAPID-AMOC and is adding biogeochemical samplers and sensors to the array, with these new instruments being deployed on the array for the first time on this cruise. The RAPID telemetry MkIII system based on the MYRTLE-X lander was deployed for the first time on the previous cruise DY039, alongside mooring EBHi, and was recovered during this cruise.

As with previous RAPID cruises we also serviced the Northern Oligiotrophic Gyre (NOG) mooring, part of the FixO3 network (more information at: http://noc.ac.uk/observatories/nog). Additional work was conducted for the MeRMEED project: (http://gtr.rcuk.ac.uk/projects?ref=NE/N001745/1), which added 24 additional temperature sensors and two 75kHz ADCPs on the WB1 mooring.

As on previous cruises we deployed a number of Argo floats supplied by the UK Met Office. In addition 6 Deep Argo floats were deployed for Scripps Institute of Oceanography.
Chief scientistDavid Smeed (National Oceanography Centre, Southampton)
ProjectRAPID Climate Change - Atlantic Meridional Overturning Circulation (AMOC)
Cruise reportRRS James Cook JC174 (JC175) cruise report jc174.pdf (28.63 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
CTD stationsQuantity: number of stations = 29
Description: CTD stations, vertical profiles of conductivity, temperature, pressure and oxygen. Samples were taken for calibration of salinity and oxygen
Current profiler (eg ADCP)Quantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
Chemical oceanography 
OxygenQuantity: number of stations = 29
Description: CTD stations, vertical profiles of conductivity, temperature, pressure and oxygen. Samples were taken for calibration of salinity and oxygen
Carbon dioxideQuantity: number of stations = 14
Description: On selected CTD stations samples were taken and stored for later analysis of dissolved inorganic carbon, and total alkalinity
PhosphateQuantity: number of stations = 21
Description: On selected CTD stations samples were taken and stored for later analysis of inorganic nutrients and organic nitrogen
Total - PQuantity: number of stations = 21
Description: On selected CTD stations samples were taken and stored for later analysis of inorganic nutrients and organic nitrogen
NitrateQuantity: number of stations = 21
Description: On selected CTD stations samples were taken and stored for later analysis of inorganic nutrients and organic nitrogen
NitriteQuantity: number of stations = 21
Description: On selected CTD stations samples were taken and stored for later analysis of inorganic nutrients and organic nitrogen
SilicateQuantity: number of stations = 21
Description: On selected CTD stations samples were taken and stored for later analysis of inorganic nutrients and organic nitrogen
pHQuantity: number of stations = 14
Description: On selected CTD stations samples were taken and stored for later analysis of dissolved inorganic carbon, and total alkalinity
Meteorology 
Incident radiationQuantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
Routine standard measurementsQuantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
Multi-beam echosoundingQuantity: activity duration in days = 38
Description: Underway measurement were made of meteorological variables (wind speed and direction, air temperature and humidity, surface pressure and irradiance); surface (5m) temperature and salinity; subsurface currents from 150kHz and 75 kHz ADCPs, along with bathymetry from single and multi-beam echo sounders.
Moorings, landers, buoys 
Physical oceanography 
CTD stations25° 52' 30" N  68° 4' 54" W — Argo autonomous profiling float deployment #23, 0-6000m
CTD stations23° 43' 36" N  38° 0' 0" W — Argo autonomous profiling float deployment #7217, 0-2000m
CTD stations23° 52' 18" N  43° 30' 0" W — Argo autonomous profiling float deployment #7216, 0-2000m
CTD stations24° 55' 12" N  62° 44' 48" W — Argo autonomous profiling float deployment #22 0-6000m
CTD stations25° 21' 47" N  55° 0' 0" W — Argo autonomous profiling float deployment #25, 0-6000m
CTD stations24° 7' 41" N  49° 0' 0" W — Argo autonomous profiling float deployment #7215, 0-2000m
Subsurface temperature and salinity measurements24° 10' 0" N  49° 44' 35" W — 18 CTD, 2 current meter, 6 oxygen, 1, pH, 1pC02, 1 sampler. 50m-5100m,
Subsurface temperature and salinity measurements26° 29' 42" N  70° 31' 23" W — 5 CTD, 1 current meter, 4800m-5500m
Subsurface temperature and salinity measurements26° 30' 47" N  76° 44' 17" W — 16 CTD, 8 current meter, 50m - 3850m
Subsurface temperature and salinity measurements23° 52' 18" N  41° 5' 24" W — 18 CTD, 2 current meter
Subsurface temperature and salinity measurements27° 48' 29" N  13° 44' 41" W — 14 CTD, 4 current meter, 100m-1400m
Subsurface temperature and salinity measurements27° 13' 18" N  15° 25' 18" W — 2CTD, 1 current meter 2500m-3000m
Subsurface temperature and salinity measurements25° 8' 24" N  52° 1' 18" W — Failed to recover: 5 CTD, 1 current meter, 4780m-5510m
Subsurface temperature and salinity measurements26° 27' 6" N  75° 43' 29" W — 15 CTD, 9 current meter, 6 Oxygen, 1 ADCP, 50m-4600m
Subsurface temperature and salinity measurements24° 56' 12" N  21° 15' 54" W — 3 CTD, 1 current meter, 3500m-4500m
Subsurface temperature and salinity measurements26° 28' 54" N  76° 37' 30" W — 8 CTD, 5 current meter, 3 oxygen, 1 sampler, 1500m-4860m
Subsurface temperature and salinity measurements27° 36' 53" N  14° 12' 36" W — 3 CTD, 1 current meter, 1600m-2000m
Subsurface temperature and salinity measurements27° 51' 0" N  13° 32' 23" W — Failed to recover: 10 CTD, 1 current meter, 100m-10000m,
Subsurface temperature and salinity measurements23° 45' 24" N  24° 9' 36" W — 18 CTD, 1 current meter, 9 oxygen, 1 50m-5000m. Failed to recover, pH, 1, pC02, 1 sampler,
Subsurface temperature and salinity measurements26° 29' 53" N  76° 48' 53" W — 5 CTD, 2 ADCP, 4 current meter, 2 oxygen, 1, pH, 1pC02, 1 sampler, 21 temperature, 50m-1350m
Current meters27° 51' 0" N  13° 32' 23" W — Failed to recover: 10 CTD, 1 current meter, 100m-10000m,
Current meters24° 56' 12" N  21° 15' 54" W — 3 CTD, 1 current meter, 3500m-4500m
Current meters24° 10' 0" N  49° 44' 35" W — 18 CTD, 2 current meter, 6 oxygen, 1, pH, 1pC02, 1 sampler. 50m-5100m,
Current meters26° 28' 54" N  76° 37' 30" W — 8 CTD, 5 current meter, 3 oxygen, 1 sampler, 1500m-4860m
Current meters26° 29' 42" N  70° 31' 23" W — 5 CTD, 1 current meter, 4800m-5500m
Current meters25° 8' 24" N  52° 1' 18" W — Failed to recover: 5 CTD, 1 current meter, 4780m-5510m
Current meters26° 30' 47" N  76° 44' 17" W — 16 CTD, 8 current meter, 50m - 3850m
Current meters23° 52' 18" N  41° 5' 24" W — 18 CTD, 2 current meter
Current meters26° 29' 53" N  76° 48' 53" W — 5 CTD, 2 ADCP, 4 current meter, 2 oxygen, 1, pH, 1pC02, 1 sampler, 21 temperature, 50m-1350m
Current meters23° 45' 24" N  24° 9' 36" W — 18 CTD, 1 current meter, 9 oxygen, 1 50m-5000m. Failed to recover, pH, 1, pC02, 1 sampler,
Current meters27° 13' 18" N  15° 25' 18" W — 2CTD, 1 current meter 2500m-3000m
Current meters26° 27' 6" N  75° 43' 29" W — 15 CTD, 9 current meter, 6 Oxygen, 1 ADCP, 50m-4600m
Current meters27° 36' 53" N  14° 12' 36" W — 3 CTD, 1 current meter, 1600m-2000m
Current meters27° 48' 29" N  13° 44' 41" W — 14 CTD, 4 current meter, 100m-1400m
Current profiler (eg ADCP)26° 31' 48" N  76° 52' 0" W — 1 ADCP 600m
Current profiler (eg ADCP)26° 27' 6" N  75° 43' 29" W — 15 CTD, 9 current meter, 6 Oxygen, 1 ADCP, 50m-4600m
Sea level (inc. bot. press., inverted echosounder)26° 30' 11" N  76° 44' 35" W — Failed to recover: 2 bottom pressure recorders, 3870m
Sea level (inc. bot. press., inverted echosounder)26° 32' 12" N  76° 53' 6" W — 1 pressure inverted echo sounder, 600m
Sea level (inc. bot. press., inverted echosounder)27° 52' 0" N  13° 30' 42" W — 2 bottom pressure recorders, 993m
Sea level (inc. bot. press., inverted echosounder)23° 51' 42" N  41° 5' 53" W — 2 bottom pressure recorders, 5030m
Sea level (inc. bot. press., inverted echosounder)27° 12' 11" N  15° 25' 0" W — 2 bottom pressure recorders, 3031m
Sea level (inc. bot. press., inverted echosounder)23° 48' 0" N  24° 7' 5" W — 2 bottom pressure recorders, 5089m (Failed recovery)
Sea level (inc. bot. press., inverted echosounder)24° 11' 59" N  49° 43' 54" W — 2 bottom pressure recorders, 5225m
Sea level (inc. bot. press., inverted echosounder)26° 28' 41" N  75° 42' 11" W — 2 bottom pressure recorders, 4690m
Chemical oceanography 
Oxygen24° 10' 0" N  49° 44' 35" W — 18 CTD, 2 current meter, 6 oxygen, 1, pH, 1pC02, 1 sampler. 50m-5100m,
Oxygen26° 28' 54" N  76° 37' 30" W — 8 CTD, 5 current meter, 3 oxygen, 1 sampler, 1500m-4860m
Oxygen26° 27' 6" N  75° 43' 29" W — 15 CTD, 9 current meter, 6 Oxygen, 1 ADCP, 50m-4600m
Oxygen26° 29' 53" N  76° 48' 53" W — 5 CTD, 2 ADCP, 4 current meter, 2 oxygen, 1, pH, 1pC02, 1 sampler, 21 temperature, 50m-1350m
Oxygen23° 45' 24" N  24° 9' 36" W — 18 CTD, 1 current meter, 9 oxygen, 1 50m-5000m. Failed to recover, pH, 1, pC02, 1 sampler,
Carbon dioxide23° 45' 24" N  24° 9' 36" W — 18 CTD, 1 current meter, 9 oxygen, 1 50m-5000m. Failed to recover, pH, 1, pC02, 1 sampler,
Carbon dioxide26° 28' 54" N  76° 37' 30" W — 8 CTD, 5 current meter, 3 oxygen, 1 sampler, 1500m-4860m
Carbon dioxide24° 10' 0" N  49° 44' 35" W — 18 CTD, 2 current meter, 6 oxygen, 1, pH, 1pC02, 1 sampler. 50m-5100m,
Carbon dioxide26° 29' 53" N  76° 48' 53" W — 5 CTD, 2 ADCP, 4 current meter, 2 oxygen, 1, pH, 1pC02, 1 sampler, 21 temperature, 50m-1350m
pH26° 29' 53" N  76° 48' 53" W — 5 CTD, 2 ADCP, 4 current meter, 2 oxygen, 1, pH, 1pC02, 1 sampler, 21 temperature, 50m-1350m
pH24° 10' 0" N  49° 44' 35" W — 18 CTD, 2 current meter, 6 oxygen, 1, pH, 1pC02, 1 sampler. 50m-5100m,
pH23° 45' 24" N  24° 9' 36" W — 18 CTD, 1 current meter, 9 oxygen, 1 50m-5000m. Failed to recover, pH, 1, pC02, 1 sampler,
pH26° 28' 54" N  76° 37' 30" W — 8 CTD, 5 current meter, 3 oxygen, 1 sampler, 1500m-4860m
Biology and fisheries 
Sediment traps23° 45' 17" N  41° 5' 41" W — 2 sediment traps + 2 current meters, c. 3000m, 1 CTD 4300m
Data held at BODC 
Discrete samples 
26  Instrument mooring