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RRS James Clark Ross JR20031128 (JR93)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20031128 (JR93)
Cruise period2003-11-28 — 2003-12-06
StatusCompleted
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnRothera, Antarctica
PurposeResearch
ObjectivesThe Southern Ocean is a major component of the coupled ocean-atmosphere climate system. It connects all the other major oceans and influences the water mass characteristics of the deep water over a large proportion of the world. It is an area of net heat loss from the ocean to the atmosphere, and is the conduit for substantial heat and freshwater exchange between the ocean basins. The objectives of the cruise were: to observe the location of the surface and subsurface manifestations of the Polar Front; to observe the deep temperature distribution; to measure the baroclinic and barotropic transport of the ACC at Drake Passage; to determine the interannual variability by comparison with previous datasets; to relate these measurements to continuous time series from moorings maintained by POL; to relate these measurements to surface SST and SSH data acquired by satellites.
High quality CTD and salinity sample measurements were made at 30 stations across Drake Passage from Elephant Island to Burdwood Bank at the same positions as occupied in previous cruises. Stations were full-depth, to within 10 metres of the seabed, with a maximum spacing of 35 km and at 50 metre bathymetry increments on the continental slopes. One other test station was carried out in Drake Passage, and the RaTS station was occupied in Marguerite Bay. The CTD package included a single downlooking WH300 Lowered ADCP. Underway measurements included single-point bathymetry, thermosalinograph, surface meteorology and shipboard ADCP down to 320 metres.
Opportunistic bathymetric mapping work and rock sample collection were also undertaken on this cruise leg lead by R Livermore, BAS (JR93). The hypothesis for JR93 was that the fragments of rock in Drake Passage may not be continental in origin and that they may not have existed during the early opening of the passage. The task during JR93 was to sample the biggest fragment, to determine its nature and age. This was achieved by:
1) bathymetric mapping, to examine the processes of crustal formation and search for sampling sites,
2) dredging any sediment-free areas of basement rock for samples.

There are two Cruise Summary Reports for JR93 (4598) and JR94 (4597).
Chief scientistBrian A King (Southampton Oceanography Centre)
ProjectCLIVAR, Drake Passage repeats
Coordinating bodyWCRP
Cruise reportRRS James Clark Ross JR20031128 (JR93) cruise report jr93.pdf (0.49 MB) 
Ocean/sea areas 
GeneralSouth Atlantic Ocean
SpecificSouthern Ocean
Track chartsRRS James Clark Ross JR20031128 (JR93) cruise track — jr93_03trk.pdf (0.52 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 19
Description: Thermosalinographs
BathythermographQuantity: number of profiles = 4
Description: XBTs
Water bottle stationsQuantity: number of stations = 32
Description: 10 bottles per station for sample salinity
CTD stationsQuantity: number of stations = 32
Description: SBE CTD - temperature and salinity
Current profiler (eg ADCP)Quantity: activity duration in days = 19
Description: Shipboard ADCP
Current profiler (eg ADCP)Quantity: number of stations = 32
Description: Lowered ADCP - RDI Workhorse 300 KHz
Meteorology 
Incident radiationQuantity: activity duration in days = 19
Description: Surface met
Routine standard measurementsQuantity: activity duration in days = 19
Description: Surface met
Geology and geophysics 
DredgeQuantity: number of deployments = 6
Description: dredger
Single-beam echosoundingQuantity: activity duration in days = 19
Description: Bathymetry - echo-sounder
Multi-beam echosoundingQuantity: activity duration in days = 7
Description: swath bathymetry survey
Magnetic measurementsQuantity: activity duration in days = 7
Description: towed magnetometer operated while ship underway
Data held at BODC Get data
Series/Profiles 
2  CTD/STD cast
Vertical spatial coordinates
Temperature of the water column
Salinity of the water column
Density of the water column
Electrical conductivity of the water column
Vertical spatial coordinates
Temperature of the water column
Salinity of the water column
Density of the water column
Electrical conductivity of the water column

BODC idDate/TimeLocationDoc.
7397642003-12-01 12:47  — 2003-12-01 13:50 59° 1' 29" S  61° 9' 58" W  View metadata report for BODC series reference number 739764
7397762003-12-06 17:46  — 2003-12-06 17:54 67° 35' 19" S  68° 8' 49" W  View metadata report for BODC series reference number 739776