Cruise inventory

RRS Discovery D308

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS Discovery (74E3)
Cruise identifierD308
Cruise period2006-07-24 — 2006-08-15
StatusCompleted
Port of departureSt. John's, Canada
Port of returnSt. John's, Canada
PurposeResearch
ObjectivesRRS Discovery cruise 308 was the fourth field campaign of the project RAPID-WAVE (West Atlantic Variability Experiment), funded by the NERC Rapid Climate Change thematic programme (RAPID).

RAPID-WAVE aims at investigating how signals associated with changes in the Atlantic meridional overturning circulation propagate along the Atlantic deep western boundary current. As part of the project, two cruises took place in 2004. In the first one, a line of 6 Bottom Pressure Recorders (BPR) was deployed in an operation area approximately located at 36.5 N 67.5 W. In the second one, two additional lines of 6 BPRs and 5 CTD moorings each were deployed on the continental shelf break approximately south of St. Johns and southeast of Halifax, respectively.

The aim of D308 was to recover and redeploy the BPRs and moorings deployed in 2004 along the St. Johns and Halifax lines. In conjunction with the recovery/redeployment operations, CTD casts were planned to be carried out and to include helium, tritium and oxygen sampling (for calibration of the CTD oxygen sensor). Measurement of tritium-helium ratios provides estimates of ventilation age up to about 20 year and is therefore very useful for inferring timescales of water-mass age and tracer transport by the Atlantic deep western boundary current.

The cruise encountered mixed success as regards the recovery of instruments: only 50% of the BPRs and 20% of the moorings could be retreived. All planned CTD casts and sampling operations were completed.
Chief scientistMiguel Angel Morales Maqueda (Proudman Oceanographic Laboratory)
ProjectRapid Climate Change (RAPID)
Coordinating bodyNatural Environment Research Council
Cruise reportRRS Discovery D308 cruise report d308.pdf — access key 'C' (4.97 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 Discovery D308 cruise track — d308trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 21
Description: The Discovery "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 = 2
Description: CTD stations conducted with UKORS SeaBird 911+ instrument:- Test site: 25/7/06, 20:33Z, to 550 m, 43 43.1N 052 14.0W Test site: 27/7/06, 22:03Z, 3150m depth, 42 54.3N 52 28.8W For each of these stations, two 300kHz LADCPs (downward and upward-looking), an oxygen sensor, a fluorometer, a transmissometer, a back scatter sensor and an altimeter were fitted on the CTD frame
CTD stationsQuantity: number of stations = 6
Description: CTD stations conducted with UKORS SeaBird 911+ instrument:- Site A0: 29/7/06, 03:53Z, 1770m depth, 43 15.7 N, 52 11.2 W Site A1: 28/7/06, 22:59Z, 2205m depth, 43 13.4 N, 52 16.5 W Site A2: 28/7/06, 18:08Z, 2785m depth, 43 07.9 N, 52 23.6 W Site A3: 11/8/06, 21:52Z, 3150m depth, 42 55.7 N, 52 28.5 W Site A4: 12/8/06, 14:57Z, 3630m depth, 42 39.9 N, 52 38.7 W Site A5: 12/8/06, 09:35Z, 4080m depth, 42 29.1 N, 52 50.2 W For each of these stations, two 300kHz LADCPs (downward and upward-looking), an oxygen sensor, a fluorometer, a transmissometer, a back scatter sensor and an altimeter were fitted on the CTD frame
CTD stationsQuantity: number of stations = 8
Description: CTD stations conducted with UKORS SeaBird 911+ instrument:- Site B0: 01/8/06, 06:40Z, 1710m depth, 43 00.3 N, 60 55.4 W Site B1: 06/8/06, 14:38Z, 2180m depth, 42 55.4 N, 60 51.9 W Site B2: 01/8/06, 23:09Z, 2680m depth, 42 49.4 N, 60 46.3 W Site B2, 06/8/06, 11:47Z, 2660m depth, 42 50.0 N, 60 46.7 W Site B3: 04/8/06, 22:42Z, 3310m depth, 42 38.4 N, 60 41.0 W Site B4: 06/8/06, 21:49Z, 3660m depth, 42 25.7 N, 60 26.2 W Site B5: 04/8/06, 02:23Z, 4100m depth, 42 13.1 N, 60 16.6 W Site B5: 08/8/06, 00:36Z, 4020m depth, 42 15.1 N, 60 18.0 W For each of these stations, two 300kHz LADCPs (downward and upward-looking), an oxygen sensor, a fluorometer, a transmissometer, a back scatter sensor and an altimeter were fitted on the CTD frame Note that two CTD casts were carried out on site B2. The second one was needed to collect a near bottom sample that was omitted in the first cast. No other bottle samples were taken in this second cast. Note that two CTD casts were carried out on site B5. The second cast was made in order to calibrate the SBE37 instruments to be deployed in the UKORS moorings. No water samples were taken in this second cast.
CTD stationsQuantity: number of stations = 3
Description: CTD stations conducted with UKORS SeaBird 911+ instrument:- Site C1: 09/8/06, 21:52Z, 4560m depth, 41 48.0 N, 60 00.0 W Site C2: 10/8/06, 18:08Z, 4760m depth, 41 57.3 N, 56 34.0 W Site C3: 11/8/06, 11:37Z, 4910m depth, 42 06.0 N, 53 09.3 W
Geochemical tracers (eg freons)Quantity: number of stations = 19
Description: Helium and tritium tracer samples were drawn from Niskin bottles on above CTD casts. Samples will be shipped back to UK. Between 11 and 16 helium/tritium samples were drawn from each cast. Six oxygen samples were also taken per cast for calibration of the oxygen sensor.
Chemical oceanography 
OxygenQuantity: number of stations = 19
Description: Helium and tritium tracer samples were drawn from Niskin bottles on above CTD casts. Samples will be shipped back to UK. Between 11 and 16 helium/tritium samples were drawn from each cast. Six oxygen samples were also taken per cast for calibration of the oxygen sensor.
Meteorology 
Incident radiationQuantity: activity duration in days = 21
Description: The Discovery "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 = 21
Description: The Discovery "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 = 21
Description: The Simrad EA500 single-beam echosounder was switched on for the duration of the cruise. Corrected depth was calculated using Carter tables. Some manual cleaning of this data was done routinely.
Moorings, landers, buoys 
Physical oceanography 
Sea level (inc. bot. press., inverted echosounder)42° 36' 0" N  60° 37' 30" W — Site B3: Bottom Pressure Recorder, deployed into 3255m (as part of UKORS mooring), 9/8/06 (jday 221), 13:06Z
Sea level (inc. bot. press., inverted echosounder)43° 15' 54" N  52° 11' 35" W — Site A0: Bottom Pressure Recorder, recovered from 1807m, 26/7/06 (Jday 207), 12:25Z
Sea level (inc. bot. press., inverted echosounder)42° 59' 53" N  60° 54' 35" W — Site B0: Bottom Pressure Recorder, recovered from 1838m, 1/8/06 (Jday 213), 11:36Z
Sea level (inc. bot. press., inverted echosounder)42° 55' 29" N  60° 51' 47" W — Site B1: Bottom Pressure Recorder, recovered from 2217m, 1/8/06 (Jday 213), 16:15Z
Sea level (inc. bot. press., inverted echosounder)42° 49' 12" N  60° 46' 29" W — Site B2: Bottom Pressure Recorder, recovered from 2714m, 1/8/06 (Jday 213), 22:47Z
Sea level (inc. bot. press., inverted echosounder)42° 37' 23" N  60° 36' 24" W — Site B3: Bottom Pressure Recorder, recovered from 3221m, 2/8/06 (Jday 214), 16:10Z
Sea level (inc. bot. press., inverted echosounder)42° 59' 53" N  60° 54' 35" W — Site B0: Bottom Pressure Recorder, deployed into 1822m, 1/8/06 (Jday 213), 12:00Z
Sea level (inc. bot. press., inverted echosounder)42° 55' 36" N  60° 51' 42" W — Site B1: Bottom Pressure Recorder, deployed into 2212m, 1/8/06 (Jday 213), 16:46Z
Sea level (inc. bot. press., inverted echosounder)42° 49' 12" N  60° 46' 29" W — Site B2: Bottom Pressure Recorder, deployed into 2704m, 6/8/06 (Jday 218), 10:45Z
Sea level (inc. bot. press., inverted echosounder)42° 26' 30" N  60° 28' 11" W — Site B4: Bottom Pressure Recorder, deployed into 3655m, 8/8/06 (Jday 220), 19:19Z
Sea level (inc. bot. press., inverted echosounder)42° 12' 29" N  60° 18' 47" W — Site B5: Bottom Pressure Recorder deployed into 4102m (as part of UKORS mooring), 8/8/06 (Jday 220), 14:35Z
Sea level (inc. bot. press., inverted echosounder)43° 12' 11" N  52° 15' 6" W — Site A1: Bottom Pressure Recorder, recovered from 2227m, 26/7/06 (Jday 207), 16:12Z
Other physical oceanographic measurements42° 36' 0" N  60° 37' 30" W — Site B3: CTD mooring, deployed into 3200m, 9/8/06 (Jday 221), 13:06Z Heights of instruments above seafloor: 0**, 250, 500*, 505***, 730, 980* (where ** denotes BPR, *** denotes current meter, * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger)
Other physical oceanographic measurements42° 12' 36" N  60° 18' 47" W — Site B5: CTD mooring, deployed into 4100m, 8/8/06 (Jday 220); 14:35Z Heights of instruments above seafloor: 0**, 250, 500*, 625, 775, 925* (where ** denotes BPR, * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger)
Other physical oceanographic measurements42° 55' 18" N  52° 29' 41" W — Site A3: Temporary current meter mooring deployed into 3220m, 11/8/06 (Jday 223), 21:24Z Heights of instruments above seafloor: 50, 500
Other physical oceanographic measurements42° 55' 54" N  52° 29' 30" W — Site A3: Temporary current meter mooring recovered from 3220m, 12/8/06 (Jday 224), 21:51Z Heights of instruments above seafloor: 50, 500
Other physical oceanographic measurements42° 27' 0" N  60° 25' 47" W — Site B4: Temporary current meter mooring deployed into 3650m, 5/8/06 (Jday 217), 22:30Z Heights of instruments above seafloor: 50, 500
Other physical oceanographic measurements42° 27' 11" N  60° 25' 18" W — Site B4: Temporary current meter mooring recovered from 3650 m, 7/8/06 (Jday 219), 11:09 Heights of instruments above seafloor: 50, 500
Other physical oceanographic measurements42° 55' 36" N  60° 51' 11" W — Site B1: CTD mooring, recovered from 2213m, 1/8/06 (Jday 213), 14:19Z Heights of instruments above seafloor: 100, 200*, 300, 400* (where * denotes CTD [Microcat with pressure sensor], and absence of * denotes CT logger)
Data held at BODC 
Series/Profiles 
5  Bottom pressure sensor tide gauge
Sea level
Temperature of the water column
Reference numbers
Date and time
Sea level
Temperature of the water column
Reference numbers
Date and time

BODC idDate/TimeLocationDoc.
10407312006-08-01 20:07:30  — 2008-02-06 17:52:16 42° 59' 56" N  60° 54' 34" W  View metadata report for BODC series reference number 1040731
10407672006-08-06 16:07:30  — 2007-10-07 12:36:54 42° 49' 10" N  60° 46' 29" W  View metadata report for BODC series reference number 1040767
10407922006-08-09 17:52:30  — 2007-10-06 12:06:54 42° 35' 58" N  60° 37' 30" W  View metadata report for BODC series reference number 1040792
10408232006-08-08 21:07:26  — 2007-09-29 19:05:31 42° 26' 28" N  60° 28' 14" W  View metadata report for BODC series reference number 1040823
10408472006-08-08 18:52:30  — 2007-10-06 16:36:54 42° 12' 33" N  60° 18' 47" W  View metadata report for BODC series reference number 1040847
20  CTD/STD cast
Density of the water column
Chlorophyll pigment concentrations in water bodies
Vertical spatial coordinates
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
Vertical spatial coordinates
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column

BODC idDate/TimeLocationDoc.
10699952006-07-25 20:26 43° 43' 5" N  52° 13' 59" W  View metadata report for BODC series reference number 1069995
10700072006-07-27 21:59 42° 54' 18" N  52° 28' 47" W  View metadata report for BODC series reference number 1070007
10700192006-07-29 03:45 43° 15' 42" N  52° 11' 12" W  View metadata report for BODC series reference number 1070019
10700202006-07-28 22:57 43° 13' 23" N  52° 16' 29" W  View metadata report for BODC series reference number 1070020
10700322006-07-28 18:00 43° 7' 54" N  52° 23' 35" W  View metadata report for BODC series reference number 1070032
10700442006-08-11 21:45 42° 55' 41" N  52° 28' 30" W  View metadata report for BODC series reference number 1070044
10700562006-08-12 14:55 42° 39' 53" N  52° 38' 42" W  View metadata report for BODC series reference number 1070056
10700682006-08-12 09:27 42° 29' 5" N  52° 50' 12" W  View metadata report for BODC series reference number 1070068
10700812006-08-01 06:30 43° 0' 18" N  60° 55' 23" W  View metadata report for BODC series reference number 1070081
10700932006-08-06 15:03 42° 55' 23" N  60° 51' 54" W  View metadata report for BODC series reference number 1070093
10701002006-08-01 22:58 42° 49' 23" N  60° 46' 18" W  View metadata report for BODC series reference number 1070100
10701122006-08-06 11:44 42° 49' 59" N  60° 46' 41" W  View metadata report for BODC series reference number 1070112
10701242006-08-04 22:35 42° 38' 24" N  60° 40' 59" W  View metadata report for BODC series reference number 1070124
10701362006-08-06 21:45 42° 25' 41" N  60° 26' 12" W  View metadata report for BODC series reference number 1070136
10701482006-08-04 02:17 42° 13' 5" N  60° 16' 36" W  View metadata report for BODC series reference number 1070148
10701612006-08-08 01:24 42° 15' 6" N  60° 17' 59" W  View metadata report for BODC series reference number 1070161
10701732006-08-09 21:47 41° 47' 59" N  60° 0' 0" W  View metadata report for BODC series reference number 1070173
10701852006-08-10 18:03 41° 57' 17" N  56° 34' 0" W  View metadata report for BODC series reference number 1070185
10701972006-08-11 11:33 42° 6' 0" N  53° 9' 18" W  View metadata report for BODC series reference number 1070197
10702042006-08-02 22:50 42° 13' 2" N  60° 16' 42" W  View metadata report for BODC series reference number 1070204
9  Moored CTD
Moored instrument depth
Electrical conductivity of the water column
Salinity of the water column
Temperature of the water column
Reference numbers
Date and time
Moored instrument depth
Electrical conductivity of the water column
Salinity of the water column
Temperature of the water column
Reference numbers
Date and time

BODC idDate/TimeLocationDoc.
9384012006-08-09 14:04:50  — 2007-10-06 12:34:50 42° 36' 0" N  60° 37' 30" W  View metadata report for BODC series reference number 938401
9384132006-08-09 14:02:22  — 2007-10-06 12:32:23 42° 36' 0" N  60° 37' 30" W  View metadata report for BODC series reference number 938413
9384252006-08-08 15:24:40  — 2007-10-06 16:24:40 42° 12' 36" N  60° 18' 47" W  View metadata report for BODC series reference number 938425
9384372006-08-08 15:23:10  — 2007-10-06 16:23:11 42° 12' 36" N  60° 18' 47" W  View metadata report for BODC series reference number 938437
9384492006-08-08 15:58:04  — 2007-10-06 16:28:04 42° 12' 36" N  60° 18' 47" W  View metadata report for BODC series reference number 938449
9385052006-08-09 14:05:59  — 2007-10-06 12:36 42° 36' 0" N  60° 37' 30" W  View metadata report for BODC series reference number 938505
9385172006-08-09 14:03:35  — 2007-10-06 12:33:36 42° 36' 0" N  60° 37' 30" W  View metadata report for BODC series reference number 938517
9385292006-08-08 15:26:13  — 2007-10-06 16:26:13 42° 12' 36" N  60° 18' 47" W  View metadata report for BODC series reference number 938529
9385302006-08-08 15:18:55  — 2007-10-06 16:48:56 42° 12' 36" N  60° 18' 47" W  View metadata report for BODC series reference number 938530
Discrete samples 
20  CTD frame plus rosette samplerDensity of the water column
Chlorophyll pigment concentrations in water bodies
Salinity of the water column
Temperature of the water column
Dissolved oxygen parameters in the water column