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RRS Discovery D253

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD253
Cruise period2001-05-04 — 2001-06-20
StatusCompleted
Port of departureSouthampton, United Kingdom
Port of returnGovan, United Kingdom
PurposeResearch
ObjectivesA multi-disciplinary survey of the Iceland Basin and Rockall Trough. There were effectively two legs: a large scale CTD survey (4 - 21 May); and a high resolution SeaSoar survey of the Iceland Faeroes Front (IFF) (2 - 20 June).

The principal objectives were:
1) reoccupation of previous Scotland-Rockall-Iceland sections (Extended Ellett Line), which wherever possible lay under altimetric satellite tracks, in order to examine inter- and intra-annual variability within the region;
2) to establish the fate of the North Atlantic Current pathways from the North Atlantic to the Norwegian Sea and the extent to which upper ocean transport occurs via eddies;
3) to map the properties of winter mode waters and to examine whether, for example, saline Eastern North Atlantic Water crosses mean flow paths to circulate from the Rockall Trough to the Reykjanes Ridge;
4) to map nutrient concentrations, phytoplankton biomass and zooplankton distributions in relation to physical regimes (eddies, fronts, seamounts, ridges, etc.);
5) to investigate the mesoscale patchiness of nutrient concentrations, phytoplankton biomass and zooplankton distributions with a view to interpreting and quantifying their interactions and response to physical forcing;
6) To contribute to Techniques for Optimising Environmental Surveys (TOES, a MOD/NERC Joint Grant Scheme Project) by testing algorithms to optimise sampling strategies and objectively design surveys according to measurement error and logistic constraints;
7) to compare properties of the deep outflows through the Faeroe Bank Channel and over the Iceland Faeroes Ridge and their downstream modification;
8) to utilise new sensors.
Chief scientistJohn T Allen (Southampton Oceanography Centre)
ProjectFISHES (Faeroes, Iceland, Scotland Hydrographic and Environmental Survey)
Coordinating bodyNERC
Cruise reportRRS Discovery D253 cruise report d253.pdf (9.32 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
SpecificIceland Basin; Rockall Trough
Track chartsRRS Discovery D253 cruise track — d253track1.pdf (0.05 MB)  RRS Discovery D253 cruise track — d253track2.pdf (0.10 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 45
Description: underway measurements T, S, fluorescence, Transmissometer, Chlorophyll, phytoplankton, nutrients
Water bottle stationsQuantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
CTD stationsQuantity: number of profiles = 162
Description: with oxygen sensor, flurometer, light scattering sensor, OPC and transmissometer and 24 bottle rosette
Subsurface temperature and salinity measurementsQuantity: number of deployments = 8
Description: SeaSoar fitted with CTD, fluorometer, FRRF (fast repetition rate fluorometer), OPC (optical particle counter)
Subsurface temperature and salinity measurementsQuantity: number of deployments = 4
Description: LHPR (Longhurst Hardy Plankton Recorder) fitted with a 333 micro metre mesh cod-end and equiped with CTD, OPC and TUBA (Towed Undulating Bio-Acoustic Instrument), a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666, 2200 k Hz).
Optics (eg underwater light levels)Quantity: number of deployments = 125
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
Current profiler (eg ADCP)Quantity: activity duration in days = 45
Description: vessel mount ADCP using 75 k Hz phased array and 150 k Hz RDI
Current profiler (eg ADCP)Quantity: number of profiles = 162
Description: using 150 k Hz RDI ADCP mounted to CTD frame
Instrumented wave measurementsQuantity: activity duration in days = 45
Description: Ship board wave recorder
Chemical oceanography 
PhosphateQuantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
PhosphateQuantity: number of samples = 478
Description: samples of nutrients during three SeaSoar surveys
NitrateQuantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
NitrateQuantity: number of samples = 478
Description: samples of nutrients during three SeaSoar surveys
NitriteQuantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
SilicateQuantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
SilicateQuantity: number of samples = 478
Description: samples of nutrients during three SeaSoar surveys
Biology and fisheries 
Primary productivityQuantity: number of stations = 21
Description: for primary production (20 CTD & 1 underway)
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of deployments = 125
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of deployments = 8
Description: SeaSoar fitted with CTD, fluorometer, FRRF (fast repetition rate fluorometer), OPC (optical particle counter)
Dissolved organic matter (inc DOC)Quantity: number of profiles = 162
Description: Rosette pylon - 24 bottles samples taken for salinity, Chl, nutrients, phytoplankton, dissolved organic carbon, dissolved organic matter, CFCs and oxygen
Biochemical measurements (eg lipids, amino acids)Quantity: number of hauls = 20
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
PhytoplanktonQuantity: number of deployments = 125
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
PhytoplanktonQuantity: activity duration in days = 45
Description: underway measurements T, S, fluorescence, Transmissometer, Chlorophyll, phytoplankton, nutrients
ZooplanktonQuantity: number of deployments = 8
Description: SeaSoar fitted with CTD, fluorometer, FRRF (fast repetition rate fluorometer), OPC (optical particle counter)
ZooplanktonQuantity: number of deployments = 4
Description: LHPR (Longhurst Hardy Plankton Recorder) fitted with a 333 micro metre mesh cod-end and equiped with CTD, OPC and TUBA (Towed Undulating Bio-Acoustic Instrument), a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666, 2200 k Hz).
ZooplanktonQuantity: number of deployments = 125
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
Eggs and larvaeQuantity: number of hauls = 26
Description: plankton net equiped with a FRRF (fast repetion rate fluorometer), pressure sensor, PAR and a multi channel high frequency SONAR (175, 250, 370, 640, 920, 1666 & 2200 k Hz).
Pelagic bacteria/micro-organismsQuantity: number of stations = 21
Description: for primary production (20 CTD & 1 underway)
Meteorology 
Routine standard measurementsQuantity: activity duration in days = 45
Description: meteorologocal measurements (atmospheric pressure, PAR, wet and dry bulb temperature, wind speed and direction).
Geology and geophysics 
Multi-beam echosoundingQuantity: activity duration in days = 43
Description: Simrad EK500 Echo Sounder three frequencies (38, 120 and 200 k Hz)
Moorings, landers, buoys 
Physical oceanography 
CTD stations55° 0' 2" N  12° 59' 53" W — APEX profiling float (ID 13353) related to Argo.
CTD stations57° 13' 53" N  10° 2' 11" W — APEX profiling float (ID 13354) related to Argo.
CTD stations61° 29' 53" N  20° 1' 23" W — APEX profiling float (ID 13355) related to Argo.
Neutrally buoyant floats61° 29' 53" N  20° 1' 23" W — APEX profiling float (ID 13355) related to Argo.
Neutrally buoyant floats55° 0' 2" N  12° 59' 53" W — APEX profiling float (ID 13353) related to Argo.
Neutrally buoyant floats57° 13' 53" N  10° 2' 11" W — APEX profiling float (ID 13354) related to Argo.
Data held at BODC Get data
Discrete samples 
154  CTD frame plus rosette samplerDissolved total and organic nitrogen concentrations in the water column
Chlorophyll pigment concentrations in water bodies
Silicate concentration parameters in the water column
Dissolved organic carbon concentration in the water column
Salinity of the water column
Nitrate concentration parameters in the water column
Dissolved oxygen parameters in the water column
Phosphate concentration parameters in the water column