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RRS Discovery D279

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD279
Cruise period2004-04-04 — 2004-05-10
StatusCompleted
Port of departureFreeport, Bahamas
Port of returnSanta Cruz de Tenerife, Spain
ObjectivesTo collect hydrographic and chemical data initially from the Florida Current at 27° N, and subsequently across the Atlantic Ocean between approximately 24 and 27.5° N.
Upon leaving Freeport, an ADCP survey of the Florida Current was conducted (east-west), followed by a nine-station CTD section (west-east) across the Current. The remainder of the cruise was then devoted to a major CTD programme (114 casts), carried out between approximately 24 and 27.5° N as the ship headed east across the Mid-Atlantic Ridge to the eastern boundary. Another objective of this cruise was to study ocean and atmospheric chemistry and so regular samples and measurements were taken alongside the main hydrographic programme as the ship returned to Santa Cruz de Tenerife.
Chief scientistStuart A Cunningham (Southampton Oceanography Centre)
ProjectRAPID
Coordinating bodyNERC
Cruise reportRRS Discovery D279 cruise report d279.pdf (8.35 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 38
Description: Sea surface hydrography underway measurements
Surface measurements underway (T,S)Quantity: activity duration in days = 38
Description: Discrete sampling from contaminated water supply for underway salinity/temperature calibration. Sampling interval every 2-8 hours (non-toxic supply was not used as water pressure was too low).
Surface measurements underway (T,S)Quantity: activity duration in days = 38
Description: Autoflux. Measurement of air-sea CO2 flux.
Water bottle stationsDescription: Water samples collected from CTD bottles for dissolved oxygen analysis (deep stations only when microelectrode sensor could not be used).
Water bottle stationsQuantity: number of samples = 1623
Description: Water samples collected from CTD bottles to determine partial pressure of CO2. Analysis by infrared absorption of CO2. Not all CTD stations were sampled.
Water bottle stationsQuantity: number of samples = 1526
Description: Water samples collected from CTD bottles to determine total alkalinity. Analysed by titration. CRMs and replicates (taken from random bottles) used as before. Not all CTD stations were sampled.
Water bottle stationsQuantity: number of samples = 1523
Description: Water samples collected from CTD bottles to determine total inorganic carbon. Analysed with coulometer, using CRMs to determine accuracy and replicates to assess precision. Not all CTD stations were sampled.
Water bottle stationsQuantity: number of stations = 120
Description: Discrete water samples taken from CTD bottles for calibration of CTD salinity (no samples for stations 11 and 28 where no bottles were fired). When less than 24 samples per cast were obtained, duplicates were taken from the deepest cast.
CTD stationsQuantity: number of stations = 123
Description: SeaBird 9/11. 126 CTD casts (including 1 test cast, excluding 3 cast failures). Parameters: temperature, salinity, pressure, oxygen, fluorescence, beam attenuation, beam transmission.
Geochemical tracers (eg freons)Quantity: number of stations = 129
Description: Water samples taken from CTD bottles for CFC analysis (CFC-12, CFC-11, CFC-13, CCl4). Most stations produced 24 samples (1 for each rosette bottle), plus one duplicate taken at random. Analysis performed using GC-EDC. Every 10 measurements were followed by analysis of a blank and standard.
Current profiler (eg ADCP)Quantity: activity duration in days = 1
Description: ADCP survey
Chemical oceanography 
OxygenQuantity: activity duration in days = 38
Description: Continuous analysis of surface pCO2 and O2 in non-toxic water supply.
OxygenDescription: Water samples collected from CTD bottles for dissolved oxygen analysis (deep stations only when microelectrode sensor could not be used).
Carbon dioxideQuantity: activity duration in days = 38
Description: Continuous analysis of surface pCO2 and O2 in non-toxic water supply.
Carbon dioxideQuantity: activity duration in days = 38
Description: Autoflux. Measurement of air-sea CO2 flux.
Carbon dioxideQuantity: number of samples = 1623
Description: Water samples collected from CTD bottles to determine partial pressure of CO2. Analysis by infrared absorption of CO2. Not all CTD stations were sampled.
AlkalinityQuantity: number of samples = 1526
Description: Water samples collected from CTD bottles to determine total alkalinity. Analysed by titration. CRMs and replicates (taken from random bottles) used as before. Not all CTD stations were sampled.
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 38
Description: Surfmet. Air temp, humidity,wind speed/direction,TIR,PAR,incoming long wave radiation, visual cloud observation.
Atmospheric chemistryQuantity: number of samples = 32
Description: Aerosol samples collected on filters over 24 hour periods (32 samples + 2 blanks taken in total). To be analysed at UEA for: nitrate, ammonia, silica, phosphate, sulphate (nutrients) and Pb, Cu, Zn, Ni, Co, Cd (trace metals) determined by GFAAS.
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 3
Description: PES bathymetry
Data held at BODC Get data
Discrete samples 
34  Bulk filtered air sampleSulphur species concentrations in the atmosphere
Metal concentrations in the atmosphere
Atmospheric deposition rates
Inorganic phosphorus species concentrations in the atmosphere
Concentration of nitrogen species in the atmosphere
Concentration of inorganic halogens in the atmosphere
125  CTD frame plus rosette samplerTotal dissolved inorganic carbon (TCO2) concentration in the water column
Dissolved total and organic nitrogen concentrations in the water column
Transmittance and attenuance of the water column
Dissolved total or organic phosphorus concentration in the water column
Temperature of the water column
Dissolved oxygen parameters in the water column
Phosphate concentration parameters in the water column
Salinity of the water column
Dissolved organic carbon concentration in the water column
Silicate concentration parameters in the water column
Other halocarbon concentrations in water bodies
Density of the water column
Metadata parameters
Chlorofluorocarbon concentrations in the water column
Nitrate concentration parameters in the water column
Alkalinity, acidity and pH of the water column
Chlorophyll pigment concentrations in water bodies
Partial pressure (pCO2) and fugacity (fCO2) of carbon dioxide in the water column
145  Sample taken from ship's non-toxic supplySalinity of the water column
8  Dissolved total and organic nitrogen concentrations in the water column
Dissolved total or organic phosphorus concentration in the water column
Phosphate concentration parameters in the water column
Silicate concentration parameters in the water column
Nitrate concentration parameters in the water column