Resources

RRS Charles Darwin CD160

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Charles Darwin (74AB)
Cruise identifierCD160
Cruise period2004-08-04 — 2004-08-24
StatusCompleted
Port of departureSt. John's, Canada
Port of returnSt. John's, Canada
PurposeResearch
ObjectivesRRS Charles Darwin cruise 160 (CD160) was the second fieldwork component of a project under the auspices of the NERC Rapid Climate Change thematic programme (Rapid). Through Rapid, funding was awarded to Dr. Chris Hughes (POL), Dr. Ric Williams (University of Liverpool) and Prof. D. Marshall (University of Reading), working in collaboration with Woods Hole Oceanographic Institution; Dr. M. Meredith (POL) was later subsumed into this grouping. The overall aim of the project was to investigate how signals propagate from higher latitudes down the western boundary of the North Atlantic, with a view to understanding the influence they might have on the large-scale overturning circulation in the Atlantic, and ultimately on climate. The fieldwork aspect of the project was to deploy arrays of Bottom Pressure Recorders (BPRs) and CTD moorings along specified satellite altimeter groundtracks off the eastern continental slope of Canada and the United States. The first stage of the deployments was conducted by RV Oceanus earlier in 2004, with one line of six BPRs being deployed on a line out towards Bermuda from the US. The purpose of CD160 was to deploy twelve further BPRs (some with Inverted Echo Sounders; IESs) and ten CTD moorings along two lines, one running approximately southwest from the Grand Banks, and a second running approximately southeast on the continental slope in front of Nova Scotia. The deployments were scheduled to be of two years duration, with recovery and redeployment in 2006, and a second recovery in 2008. Continuation beyond this would depend on future availability of funding. Whilst the top priority of CD160 was the BPR and mooring deployments, it was intended to also conduct CTD casts at each of the twelve sites. The CTD frame was fitted with two Lowered Acoustic Doppler Current Profilers (LADCPs; one 150kHz and one 300kHz) to gain information on full-depth current velocities. Samples were to be drawn from the CTD rosette-mounted Niskins and stored for future analysis for the ratio of oxygen isotopes in seawater (d18O), and iodine-129 (I129). The first of these provides information on the high-latitude sources that provide freshwater signals to the Deep Western Boundary Current (DWBC) of the North Atlantic. The second is the signature of discharge from European nuclear power plants; as a radioactive (and therefore time-dependent) tracer, it provides information on timescales for waters to circulate northward past Europe, circuit or short-circuit the Arctic, and subsequently flow southward in the DWBC. Each of these measurements would provide differing insights into the region under study, and contribute to answering the larger question of how the ocean influences climate. In practice, the CTD work was not entirely successful: the original CTD/LADCP package was lost in 3650m of water, and not recovered. A second CTD was borrowed from Bedford Institute of Oceanography (Halifax, Nova Scotia), but there was insufficient time to complete the whole planned series of casts - 2 CTDs were omitted.
Chief scientistMichael P Meredith (Proudman Oceanographic Laboratory)
ProjectRAPID
Coordinating bodyNatural Environment Research Council (NERC)
Cruise reportRRS Charles Darwin CD160 cruise report cd160.pdf (2.82 MB) 
Ocean/sea areas 
GeneralNorth West Atlantic Ocean (limit 40W)
SpecificContinental slope southwest of Grand Banks, and continental slope southeast of Nova Scotia
Track chartsRRS Charles Darwin CD160 cruise track — cd160roscop4641trk.pdf (0.27 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 19
Description: meteorolgy measurements. The Darwin 'surfmet' package was switched on for the duration of the cruise, providing thermosalinograph measurements (sea surface temperature, conductivity, fluorescence, beam transmission) and meteorology measurements (barometric pressure, wind speed & direction, air temperature, humidity, photosynthetically-active radiation and total incidence radiation). True wind speed and direction (rather than relative to ship) were derived, and uncalibrated sea surface salinity.
CTD stationsQuantity: number of stations = 5
Description: CTD stations conducted with original (UKORS) SeaBird 911+ instrument:- Site A0: 6/8/04, 18:20Z, 1810m depth, 43deg 16.38' N, 52deg 11.40' W Site A1: 7/8/04, 11:26Z, 2212m depth, 43deg 11.84' N, 52deg 14.59' W Site A2: 7/8/04, 17:44Z, 2724m depth, 43deg 06.58' N, 52deg 19.60' W Site A3: 8/8/04, 10:41Z, 3228m depth, 42deg 54.79' N, 52deg 29.20' W Site A4: 8/8/04, 20:50Z, 3672m depth, 42deg 40.02' N, 52deg 40.71' W For each of these stations, a 150kHz LADCP and a 300kHz LADCP were fitted on the CTD frame: raw datafiles are available for Sites A0-A3. The CTD/LADCP package was lost during recovery at Site A4, hence no LADCP data are available for this and subsequent sites.
CTD stationsQuantity: number of stations = 5
Description: CTD stations conducted with replacement (Bedford Institute of Oceanography) SeaBird 911+ instrument:- Site B5: 20/8/04, 21:21Z, 4105m depth, 42deg 13.81' N, 60deg 17.62' W Site B4: 21/8/04, 11:22Z, 3648m depth, 42deg 26.72' N, 60deg 27.70' W Site B3: 21/8/04, 17:14Z, 3229m depth, 42deg 37.06' N, 60deg 36.49' W Site B2: 21/8/04, 22:02Z, 2748m depth, 42deg 48.86' N, 60deg 46.03' W Site B1: 22/8/04, 11:07Z, 2214m depth, 42deg 55.83' N, 60deg 50.97' W.
Geochemical tracers (eg freons)Quantity: number of stations = 9
Description: Tracer samples were drawn from Niskins on above CTD casts, with the exception of Site A4 (the loss of the package during recovery prevented sampling). Samples will be shipped back to UK, and analysed for oxygen isotopes and iodine-129. 24 samples were drawn from each cast for oxygen isotopes, and around 12 per cast for iodine-129.
Meteorology 
Incident radiationQuantity: activity duration in days = 19
Description: meteorolgy measurements. The Darwin 'surfmet' package was switched on for the duration of the cruise, providing thermosalinograph measurements (sea surface temperature, conductivity, fluorescence, beam transmission) and meteorology measurements (barometric pressure, wind speed & direction, air temperature, humidity, photosynthetically-active radiation and total incidence radiation). True wind speed and direction (rather than relative to ship) were derived, and uncalibrated sea surface salinity.
Routine standard measurementsQuantity: activity duration in days = 19
Description: meteorolgy measurements. The Darwin 'surfmet' package was switched on for the duration of the cruise, providing thermosalinograph measurements (sea surface temperature, conductivity, fluorescence, beam transmission) and meteorology measurements (barometric pressure, wind speed & direction, air temperature, humidity, photosynthetically-active radiation and total incidence radiation). True wind speed and direction (rather than relative to ship) were derived, and uncalibrated sea surface salinity.
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 19
Description: single-beam echosounder measurements. The Simrad EA500 single-beam echosounder was switched on for the duration of the cruise. Corrected depth was calculated using the RVS prodep function. Some manual cleaning of this data was done routinely.
Multi-beam echosoundingQuantity: activity duration in days = 19
Description: swath bathymetry measurements. The Simrad EM120 multi-beam echosounder (swath system) was turned on for most of the cruise. Sparse sound speed profiles were derived from CTD casts as input to the swath system. Raw data were logged; no processing was conducted onboard.
Moorings, landers, buoys 
Physical oceanography 
Sea level (inc. bot. press., inverted echosounder)43° 16' 18" N  52° 11' 23" W — Site A0: Bottom Pressure Recorder, deployed into 1807m, 6/8/04 (Jday 219), 20:58Z
Sea level (inc. bot. press., inverted echosounder)43° 11' 48" N  52° 14' 53" W — Site A1: Bottom Pressure Recorder, deployed into 2227m, 7/8/04 (Jday 220), 14:16Z
Sea level (inc. bot. press., inverted echosounder)42° 13' 54" N  60° 18' 24" W — Site B5: Bottom Pressure Recorder/Inverted Echo Sounder deployed into 4099m, 20/8/04 (Jday 233), 19:07Z
Sea level (inc. bot. press., inverted echosounder)42° 26' 23" N  60° 28' 18" W — Site B4: Bottom Pressure Recorder, deployed into 3665m, 19/8/04 (Jday 232), 18:21Z
Sea level (inc. bot. press., inverted echosounder)42° 37' 11" N  60° 36' 42" W — Site B3: Bottom Pressure Recorder, deployed into 3221m, 21/8/04 (jday 234), 16:29Z
Sea level (inc. bot. press., inverted echosounder)42° 49' 12" N  60° 46' 23" W — Site B2: Bottom Pressure Recorder, deployed into 2714m, 18/8/04 (Jday 231), 23:02Z
Sea level (inc. bot. press., inverted echosounder)42° 55' 36" N  60° 51' 35" W — Site B1: Bottom Pressure Recorder, deployed into 2217m, 18/8/04, (Jday 231), 20:16Z
Sea level (inc. bot. press., inverted echosounder)42° 59' 48" N  60° 54' 35" W — Site B0: Bottom Pressure Recorder, deployed into 1838m, 18/8/04 (Jday 231), 17:13Z
Sea level (inc. bot. press., inverted echosounder)42° 28' 41" N  52° 50' 24" W — Site A5: Bottom Pressure Recorder, deployed into 4122m, 11/8/04 (Jday 224), 10:59Z
Sea level (inc. bot. press., inverted echosounder)42° 40' 0" N  52° 40' 47" W — Site A4: Bottom Pressure Recorder, deployed into 3666m, 10/8/04 (Jday 223), 22:43Z
Sea level (inc. bot. press., inverted echosounder)42° 54' 53" N  52° 29' 5" W — Site A3: Bottom Pressure Recorder, deployed into 3220m, 8/8/04 (Jday 221), 13:42Z
Sea level (inc. bot. press., inverted echosounder)43° 6' 42" N  52° 19' 36" W — Site A2: Bottom Pressure Recorder, deployed into 2716m, 7/8/04 (Jday 220), 20:35Z
Other physical oceanographic measurements42° 37' 18" N  60° 36' 54" W — Site B3: CTD mooring, deployed into 3209m, 19/8/04 (Jday 232), 16:35Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500*, 1000, 1400* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 49' 12" N  60° 46' 23" W — Site B2: CTD mooring, deployed into 2714m, 19/8/04 (Jday 232), 00:17Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 55' 41" N  60° 51' 42" W — Site B1: CTD mooring, deployed into 2213m, 18/8/04 (Jday 231), 21:43Z. Heights of instruments above seafloor: 100, 200*, 300, 400* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 28' 36" N  52° 50' 17" W — Site A5: CTD mooring, deployed into 4119m, 11/8/04 (Jday 224), 17:13Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500, 900, 1400*, 1900, 2300* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 13' 59" N  60° 18' 17" W — Site B5: CTD mooring, deployed into 4099m, 20/8/04 (Jday 233); 19:00Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500, 900, 1400*, 1900, 2300* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 54' 47" N  52° 28' 54" W — Site A3: CTD mooring, deployed into 3222m, 8/8/04 (Jday 221), 17:08Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500*, 1000, 1400* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger.
Other physical oceanographic measurements43° 6' 35" N  52° 19' 23" W — Site A2: CTD mooring, deployed into 2719m, 7/8/04 (Jday 220): 21:43Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements43° 12' 0" N  52° 14' 53" W — Site A1: CTD mooring, deployed into 2217m, 7/8/04 (Jday 220), 14:00Z. Heights of instruments above seafloor: 100, 200*, 300, 400* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 26' 23" N  60° 28' 18" W — Site B4: CTD mooring, deployed into 3665m, 19/8/04 (Jday 232), 20:24Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Other physical oceanographic measurements42° 40' 5" N  52° 40' 47" W — Site A4: CTD mooring, deployed into 3666m, 10/8/04 (Jday 223), 23:25Z. Heights of instruments above seafloor: 100, 200*, 300, 400, 500* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger).
Data held at BODC Get data
Series/Profiles 
6  Bottom pressure sensor tide gauge
Reference numbers
Date and time
Temperature of the water column
Sea level
Reference numbers
Date and time
Temperature of the water column
Sea level

BODC idDate/TimeLocationDoc.
10407182004-08-18 19:37:30  — 2006-07-31 20:52:12 42° 59' 50" N  60° 54' 34" W  View metadata report for BODC series reference number 1040718
10406992004-08-06 23:07:30  — 2006-07-26 11:19:05 43° 15' 34" N  52° 11' 15" W  View metadata report for BODC series reference number 1040699
10407802004-08-21 17:52:30  — 2006-08-02 11:20:49 42° 37' 12" N  60° 36' 43" W  View metadata report for BODC series reference number 1040780
10407432004-08-18 22:22:30  — 2005-10-31 22:22:30 42° 55' 38" N  60° 51' 37" W  View metadata report for BODC series reference number 1040743
10407062004-08-07 19:52:30  — 2006-07-26 15:06:29 43° 11' 54" N  52° 14' 57" W  View metadata report for BODC series reference number 1040706
10407552004-08-19 02:22:30  — 2006-07-31 23:52:23 42° 49' 9" N  60° 46' 26" W  View metadata report for BODC series reference number 1040755
10  CTD/STD cast
Transmittance and attenuance of the water column
Salinity of the water column
Temperature of the water column
Vertical spatial coordinates
Dissolved oxygen parameters in the water column
Density of the water column
Chlorophyll pigment concentrations in water bodies
Transmittance and attenuance of the water column
Salinity of the water column
Temperature of the water column
Vertical spatial coordinates
Dissolved oxygen parameters in the water column
Density of the water column
Chlorophyll pigment concentrations in water bodies

BODC idDate/TimeLocationDoc.
10663102004-08-20 21:23 42° 13' 50" N  60° 17' 39" W  View metadata report for BODC series reference number 1066310
10662662004-08-07 11:29 43° 11' 14" N  52° 14' 13" W  View metadata report for BODC series reference number 1066266
10662782004-08-07 17:48 43° 6' 37" N  52° 19' 29" W  View metadata report for BODC series reference number 1066278
10663582004-08-22 11:10 42° 56' 1" N  60° 51' 17" W  View metadata report for BODC series reference number 1066358
10663342004-08-21 17:17 42° 36' 58" N  60° 36' 38" W  View metadata report for BODC series reference number 1066334
10662542004-08-06 18:20 43° 16' 9" N  52° 10' 54" W  View metadata report for BODC series reference number 1066254
10663092004-08-08 20:52 42° 39' 47" N  52° 40' 24" W  View metadata report for BODC series reference number 1066309
10663222004-08-21 11:26 42° 26' 42" N  60° 27' 44" W  View metadata report for BODC series reference number 1066322
10662912004-08-08 10:54 42° 55' 5" N  52° 29' 22" W  View metadata report for BODC series reference number 1066291
10663462004-08-21 22:05 42° 48' 51" N  60° 46' 9" W  View metadata report for BODC series reference number 1066346
1  GPS positioning system
Horizontal spatial co-ordinates
Date and time
Platform or instrument orientation
Horizontal platform movement
Bathymetry and Elevation
Horizontal spatial co-ordinates
Date and time
Platform or instrument orientation
Horizontal platform movement
Bathymetry and Elevation

BODC idDate/TimeLocationDoc.
7883392004-08-04 19:56  — 2004-08-24 10:58 42° 11' 38" N  63° 36' 56" W — 47° 28' 33" N  52° 10' 13" W  View metadata report for BODC series reference number 788339
1  Meteorological data logger
Visible waveband radiance and irradiance measurements in the atmosphere
Horizontal spatial co-ordinates
Air pressure
Date and time
Air temperature
Wind strength and direction
Solar Radiation
Atmospheric humidity
Visible waveband radiance and irradiance measurements in the atmosphere
Horizontal spatial co-ordinates
Air pressure
Date and time
Air temperature
Wind strength and direction
Solar Radiation
Atmospheric humidity

BODC idDate/TimeLocationDoc.
7883272004-08-04 19:56  — 2004-08-24 10:58 42° 11' 38" N  63° 36' 56" W — 47° 28' 33" N  52° 10' 13" W  View metadata report for BODC series reference number 788327
9  Moored CTD
Moored instrument depth
Reference numbers
Date and time
Salinity of the water column
Temperature of the water column
Electrical conductivity of the water column
Moored instrument depth
Reference numbers
Date and time
Salinity of the water column
Temperature of the water column
Electrical conductivity of the water column

BODC idDate/TimeLocationDoc.
8629952004-08-18 22:30  — 2006-05-08 02:30:01 42° 55' 42" N  60° 51' 44" W  View metadata report for BODC series reference number 862995
8629342004-08-18 22:30:01  — 2006-07-04 21:00:02 42° 55' 42" N  60° 51' 44" W  View metadata report for BODC series reference number 862934
8629712004-08-19 01:30  — 2006-08-01 20:00:01 42° 49' 14" N  60° 46' 29" W  View metadata report for BODC series reference number 862971
8629462004-08-18 22:30  — 2006-06-24 23:30:02 42° 55' 42" N  60° 51' 44" W  View metadata report for BODC series reference number 862946
8629582004-08-19 01:30  — 2006-08-01 21:30:03 42° 49' 14" N  60° 46' 29" W  View metadata report for BODC series reference number 862958
8630092004-08-18 22:30  — 2006-04-27 05:30:02 42° 55' 42" N  60° 51' 44" W  View metadata report for BODC series reference number 863009
8630102004-08-19 01:30  — 2006-05-05 21:00:01 42° 49' 14" N  60° 46' 29" W  View metadata report for BODC series reference number 863010
8630222004-08-19 01:30  — 2006-04-27 15:30:01 42° 49' 14" N  60° 46' 29" W  View metadata report for BODC series reference number 863022
8629832004-08-19 01:30:01  — 2006-08-01 21:00:02 42° 49' 14" N  60° 46' 29" W  View metadata report for BODC series reference number 862983
1  Thermosalinograph
Horizontal spatial co-ordinates
Transmittance and attenuance of the water column
Date and time
Salinity of the water column
Temperature of the water column
Raw suspended particulate material concentration sensor output
Raw fluorometer output
Horizontal spatial co-ordinates
Transmittance and attenuance of the water column
Date and time
Salinity of the water column
Temperature of the water column
Raw suspended particulate material concentration sensor output
Raw fluorometer output

BODC idDate/TimeLocationDoc.
7921912004-08-04 19:56  — 2004-08-24 10:58 42° 11' 38" N  63° 36' 56" W — 47° 28' 33" N  52° 10' 13" W  View metadata report for BODC series reference number 792191
Discrete samples 
10  CTD frame plus rosette samplerTransmittance and attenuance of the water column
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column
Density of the water column
Chlorophyll pigment concentrations in water bodies
22  Instrument mooring
24  Sample taken from ship's non-toxic supplySalinity of the water column