Resources

RRS James Clark Ross JR19970421 (AMT4, JR21)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR19970421 (AMT4, JR21)
Cruise period1997-04-21 — 1997-05-27
StatusCompleted
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnGrimsby, United Kingdom
ObjectivesThe Atlantic Meridional Transects (AMTs) were conceived as a means of acquiring a time series of oceanographic, biological, chemical and optical data over large latitudinal ranges (50° N to 50° S) and through a number of contrasting oceanographic provinces. The core scientific objectives are to refine out understanding of the role of the ocean biota in the biogeochemical processes, carbon fluxes and ultimately global climate and to develop remotely-sensed measurements of global primary production.

The AMTs take advantage of the twice yearly passage of the NERC vessel, RRS James Clark Ross, operated by the British Antarctic Survey, during its passage to and from Antarctica each year. Since the only ship costs involved are to cover the additional time required for course deviations and station work, the AMT is a highly cost-effective project for fundamental marine science. AMT-4 is the fourth Atlantic transect in the current series.

Aims:

1. To improve our undestanding of the relationship between physical processes and biological production.
2. Identify, define and quantify latitudinal changes in biogeochemical provinces.
3. Determine phytoplankton characteristics and photosynthetic parameters.
4. Identify nutrient regimes and their role in biogeochemical cycles.
5. Characterise plankton community structure, including the accurate determination of carbon values
6. Relate the partial pressure of CO2 (pCO2) in surface waters with the biological production
7. Acquire data for the calibration of remotely sensed obersvations (primary validation).
8. Secondary validation of remotely sensed products (e.g. chlorophyll concentration).
9. Interpret basin-scale remote sensing observations
10. Develop models that enable the interpretation of satellite imagery in terms of total water column properties.
Chief scientistTony Bale (Plymouth Marine Laboratory)
ProjectAMT
Cruise reportRRS James Clark Ross JR19970421 (AMT4, JR21) cruise report jr_amt4.pdf (3.65 MB) 
Ocean/sea areas 
GeneralNorth Atlantic Ocean
South Atlantic Ocean
Track chartsRRS James Clark Ross JR19970421 (AMT4, JR21) cruise track — jr_amt4track.pdf (0.03 MB) 
Measurements 
Physical oceanography 
Water bottle stationsDescription: The stations were sampled for a number of things. Bottle casts were taken for plankton samples. Samples were then taken for pigment analysis. CTD casts were made. Sky and sea photo graphs were taken. Optical stations were carried out. No. of stations not noted.
CTD stationsDescription: The stations were sampled for a number of things. Bottle casts were taken for plankton samples. Samples were then taken for pigment analysis. CTD casts were made. Sky and sea photo graphs were taken. Optical stations were carried out. No. of stations not noted.
Subsurface temperature and salinity measurementsDescription: Underway measurements including salinity, temperature and fluorescence were taken. No. of samples not noted.
Optics (eg underwater light levels)Description: The stations were sampled for a number of things. Bottle casts were taken for plankton samples. Samples were then taken for pigment analysis. CTD casts were made. Sky and sea photo graphs were taken. Optical stations were carried out. No. of stations not noted.
Optics (eg underwater light levels)Description: Optical oceanography samples were taken. No. of samples not noted.
Chemical oceanography 
Carbon dioxideDescription: CO2 samples were collected for analysis. No. of samples not noted.
Biology and fisheries 
Phytoplankton pigs (eg chlorophyll, fluorescence)Description: Underway measurements including salinity, temperature and fluorescence were taken. No. of samples not noted.
PhytoplanktonDescription: Studies of phytoplankton and zooplankton communities are made. No. of sample not noted.
ZooplanktonDescription: Studies of phytoplankton and zooplankton communities are made. No. of sample not noted.
ZooplanktonDescription: The stations were sampled for a number of things. Bottle casts were taken for plankton samples. Samples were then taken for pigment analysis. CTD casts were made. Sky and sea photo graphs were taken. Optical stations were carried out. No. of stations not noted.
Data held at BODC Get data
Discrete samples 
66  CTD frame plus rosette samplerPhytoplankton taxonomic biomass in water bodies
Particulate total and organic nitrogen concentrations in the water column
Particulate total and organic carbon concentrations in the water column
Density of the water column
Bacteria non taxonomy-related biomass expressed as carbon per unit volume of the water column
Bacteria generic abundance in water bodies
Phytoplankton taxonomic abundance in water bodies
Primary production in the water column
Metadata parameters
Chlorophyll pigment concentrations in water bodies
Silicate concentration parameters in the water column
Salinity of the water column
Nitrate concentration parameters in the water column
Plankton abundance per unit volume of the water column
Temperature of the water column
Carotenoid and flavenoid pigment concentrations in water bodies
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
Phaeopigment concentrations in the water column
Reference numbers
Plankton biomass expressed as carbon per unit volume of the water column
140  Expendable BathythermographTemperature of the water column
336  Sample taken from ship's non-toxic supplyChlorophyll pigment concentrations in water bodies
Carotenoid and flavenoid pigment concentrations in water bodies
144  WP-2 zooplankton net