Cruise inventory

RRS James Clark Ross JR20091118 (JR195, JR198)

Cruise summary report

Cruise Info. 
Ship name (ship code)RRS James Clark Ross (74JC)
Cruise identifierJR20091118 (JR195, JR198)
Cruise period2009-11-18 — 2009-11-27
StatusCompleted
Port of departureStanley, Falkland Islands (Malvinas)
Port of returnRothera, Antarctica
PurposeResearch
ObjectivesThe objective of the cruise was to perform a CTD section across Drake Passage (Figure 1.1), repeating measurements made during previous research cruises for the purpose of long-term monitoring. Drake Passage is the narrowest passage through which the Antarctic Circumpolar Current (ACC) flows, and thus is a convenient location for making measurements across the entire ACC. A repeat hydrographic section across Drake Passage (SR1) was established by the World Ocean Circulation Experiment and first occupied by the R/V Meteor in 1990. Subsequently, the section was moved eastwards to lie on a satellite ground track with the northern end on the south side of Burdwood Bank, south of the Falkland Islands, and the southern end off Elephant Island at the tip of the Antarctic Peninsula. This revised section location was designated SR1b and was first occupied by the R/V Polarstern in 1992 and by RRS Discovery the same year using SeaSoar only. It has since been occupied 15 times by the UK at nearly one section per year on the RRS James Clark Ross (two exceptions: 1995 and 1998).

The objective of this section is to look at changes on interannual to decadal scales. The key objectives for the JR195 CTD section across Drake Passage are:

(i) to determine the interannual variability of the position, structure and transport of the Antarctic Circumpolar Current (ACC) in Drake Passage;
(ii) to examine the fronts associated with the ACC, and to determine their positions and strengths;
(iii) by comparing geostrophic velocities with those measured directly (by the lowered ADCP), to determine the size of ageostrophic motions, and to attempt to estimate the barotropic components;
(iv) to examine the temperature and salinity structure of the water flowing through Drake Passage, and thus identify the significant water masses;
(v) to calculate the total flux of water through Drake Passage by combining all available measurements.

Thirty one full depth stations were performed during JR195: two test stations, and 29 of the 30 nominal stations for the SR1b Drake Passage section. Two 500 m stations were added as part of POL's cruise JR198. The CTD was an underwater SBE 9 plus unit equipped with the following sensors: dual temperature and conductivity sensors, a SBE-43 oxygen probe, an Aquatracka MKIII fluorometer, a transmissometer, an upward-looking downwelling PAR sensor, and an altimeter. A downward-looking LADCP (RDI Workhorse Monitor 300 kHz) was deployed on the CTD frame at all stations, except for the two JR198 500 m stations when it was replaced by a 600 kHz LADCP from Bangor University (see separate CSR).

Various underway measurements were obtained, including navigation, VM-ADCP, sea surface temperature and salinity, water depth and various meteorological parameters.
Chief scientistMargaret J Yelland (National Oceanography Centre, Southampton)
ProjectACCLAIM (Antarctic Circumpolar Current Levels by Altimetry and Islands Measurements)
Coordinating bodyNatural Environment Research Council (NERC)
Cruise reportRRS James Clark Ross JR20091118 (JR195, JR198) cruise report jr195.pdf — access key 'C' (30 MB) 
Ocean/sea areas 
GeneralSouthern Ocean
SpecificDrake Passage
Track chartsRRS James Clark Ross JR20091118 (JR195, JR198) cruise track — jr195trk.pdf (00 MB) 
Measurements 
Physical oceanography 
Surface measurements underway (T,S)Quantity: activity duration in days = 12
Description: JCR surface hydrography sensors suite including a fluorometer, a SBE45 thermosalinograph measuring conductivity and water temperature for salinity measurements, a hull mounted PRT100 sea surface temperature sensor (located close to the non-toxic supply intake on the hull at a depth on 6m).
Surface measurements underway (T,S)Quantity: number of samples = 35
Description: Bottle salinity samples collected from non-toxic water supply and analysed by bench salinometer
Water bottle stationsQuantity: number of samples = 228
Description: Bottle salinity samples collected with rosette sampler analysed by bench salinometer
CTD stationsQuantity: number of stations = 31
Description: SBE911 plus CTD and rosette sampler equipped with dual temperature and conductivity sensors, SBE-43 oxygen probe, Aquatracka MKIII fluorometer, transmissometer, upward-looking downwelling PAR sensor, and altimeter.
Transparency (eg transmissometer)Quantity: number of stations = 31
Description: SBE911 plus CTD and rosette sampler equipped with dual temperature and conductivity sensors, SBE-43 oxygen probe, Aquatracka MKIII fluorometer, transmissometer, upward-looking downwelling PAR sensor, and altimeter.
Optics (eg underwater light levels)Quantity: number of stations = 31
Description: SBE911 plus CTD and rosette sampler equipped with dual temperature and conductivity sensors, SBE-43 oxygen probe, Aquatracka MKIII fluorometer, transmissometer, upward-looking downwelling PAR sensor, and altimeter.
Current profiler (eg ADCP)Quantity: number of stations = 31
Description: Downward-looking RDI Workhorse Monitor 300 kHz LADCP mounted on the CTD frame.
Current profiler (eg ADCP)Quantity: activity duration in days = 12
Description: 75 kHz RD Instruments Ocean Surveyor (OS75) Vessel Mounted ADCP
Other physical oceanographic measurementsQuantity: number of profiles = 20
Description: Vertical microstructure profiling was carried out on 25/11/2009 from 9:43Z to 11:36Z in an area adjacent to the Drake South shallow BPR. The VMP cast were to ~900 m and recorded standard T, C and P plus high resolution T,C, P, current shear and fluorescence.
Chemical oceanography 
OxygenQuantity: number of stations = 31
Description: SBE911 plus CTD and rosette sampler equipped with dual temperature and conductivity sensors, SBE-43 oxygen probe, Aquatracka MKIII fluorometer, transmissometer, upward-looking downwelling PAR sensor, and altimeter.
Biology and fisheries 
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: number of stations = 31
Description: SBE911 plus CTD and rosette sampler equipped with dual temperature and conductivity sensors, SBE-43 oxygen probe, Aquatracka MKIII fluorometer, transmissometer, upward-looking downwelling PAR sensor, and altimeter.
Phytoplankton pigs (eg chlorophyll, fluorescence)Quantity: activity duration in days = 12
Description: JCR surface hydrography sensors suite including a fluorometer, a SBE45 thermosalinograph measuring conductivity and water temperature for salinity measurements, a hull mounted PRT100 sea surface temperature sensor (located close to the non-toxic supply intake on the hull at a depth on 6m).
Meteorology 
Incident radiationQuantity: activity duration in days = 12
Description: short wave radiation (TIR), photosynthetically active radiation (PAR)
Other meteorological measurementsQuantity: activity duration in days = 12
Description: JCR meteorological sensors suite to measure: air temperature and humidity, atmospheric pressure, short wave radiation (TIR), photosynthetically active radiation (PAR) and wind speed and direction.
Geology and geophysics 
Single-beam echosoundingQuantity: activity duration in days = 12
Description: Bathymetry by a Kongsberg EA600 single beam echo sounder
Moorings, landers, buoys 
Physical oceanography 
Sea level (inc. bot. press., inverted echosounder)54° 57' 0" S  58° 21' 35" W — Site Drake North: Easterly Bottom Pressure Recorder with microCAT deployed in 2008, recovered from ~1000 m, 19/11/09, 13:19Z
Sea level (inc. bot. press., inverted echosounder)54° 57' 0" S  58° 22' 48" W — Site Drake North: Westerly Bottom Pressure Recorder deployed in 2007, recovered from ~1000 m, 19/11/09, 14:44Z
Sea level (inc. bot. press., inverted echosounder)54° 56' 23" S  58° 21' 35" W — Site Drake North: Bottom Pressure Recorder with microCAT, deployed to ~1000 m, 19/11/09, 15:02Z
Sea level (inc. bot. press., inverted echosounder)60° 51' 0" S  54° 42' 36" W — Site Drake South shallow: Bottom Pressure Recorder deployed to ~1000 m, 25/11/09, 01:06Z
Sea level (inc. bot. press., inverted echosounder)60° 37' 11" S  53° 49' 47" W — MYRTLE Site: unsuccessful attempt a recovering a MYRTLE capsule and, subsequently, the MYRTLE frame, depth ~2800 m , 24/11/09, 12:59Z-16:06Z
Sea level (inc. bot. press., inverted echosounder)60° 49' 12" S  54° 43' 47" W — Site Drake South deep: Bottom Pressure Recorder with microCAT, deployed to ~2000 m, 24/11/09, 21:21Z
Sea level (inc. bot. press., inverted echosounder)60° 51' 0" S  54° 42' 36" W — Site Drake South: Bottom Pressure Recorder deployed in 2007, recovered from ~1000 m, 25/11/09, 00:53Z
Sea level (inc. bot. press., inverted echosounder)57° 52' 48" S  56° 31' 48" W — Site Drake Middle: Bottom Pressure Recorder with microCAT, deployed in 2008, recovered from ~4000m, 22/11/09, 20:56Z
Data held at BODC 
Series/Profiles 
33  CTD/STD cast
Density of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies
Vertical spatial coordinates
Salinity of the water column
Temperature of the water column
Reference numbers
Dissolved oxygen parameters in the water column
Density of the water column
Electrical conductivity of the water column
Chlorophyll pigment concentrations in water bodies
Vertical spatial coordinates
Salinity of the water column
Temperature of the water column
Reference numbers
Dissolved oxygen parameters in the water column

BODC idDate/TimeLocationDoc.
10520742009-11-19 05:23:37 54° 39' 59" S  58° 32' 40" W  View metadata report for BODC series reference number 1052074
10520862009-11-19 07:47:54 54° 55' 23" S  58° 22' 56" W  View metadata report for BODC series reference number 1052086
10520982009-11-19 09:05:11 54° 56' 40" S  58° 22' 18" W  View metadata report for BODC series reference number 1052098
10521052009-11-19 10:35:37 54° 57' 42" S  58° 21' 37" W  View metadata report for BODC series reference number 1052105
10521172009-11-19 16:41:19 55° 4' 21" S  58° 16' 35" W  View metadata report for BODC series reference number 1052117
10521292009-11-19 18:52:01 55° 7' 32" S  58° 14' 31" W  View metadata report for BODC series reference number 1052129
10521302009-11-19 21:45:41 55° 10' 44" S  58° 11' 49" W  View metadata report for BODC series reference number 1052130
10521422009-11-21 02:20:26 55° 22' 5" S  58° 5' 56" W  View metadata report for BODC series reference number 1052142
10521542009-11-21 08:19:27 55° 50' 0" S  57° 49' 14" W  View metadata report for BODC series reference number 1052154
10521662009-11-21 13:49:34 56° 9' 0" S  57° 37' 27" W  View metadata report for BODC series reference number 1052166
10521782009-11-21 18:08:50 56° 27' 59" S  57° 25' 40" W  View metadata report for BODC series reference number 1052178
10521912009-11-21 22:42:36 56° 46' 58" S  57° 13' 59" W  View metadata report for BODC series reference number 1052191
10522092009-11-22 03:20:35 57° 6' 0" S  57° 2' 0" W  View metadata report for BODC series reference number 1052209
10522102009-11-22 08:11:44 57° 24' 57" S  56° 49' 58" W  View metadata report for BODC series reference number 1052210
10522222009-11-22 12:42:21 57° 43' 53" S  56° 38' 13" W  View metadata report for BODC series reference number 1052222
10522342009-11-22 16:20:41 57° 53' 45" S  56° 32' 41" W  View metadata report for BODC series reference number 1052234
10522462009-11-23 00:06:50 58° 21' 59" S  56° 15' 0" W  View metadata report for BODC series reference number 1052246
10522582009-11-23 04:53:35 58° 40' 59" S  56° 3' 13" W  View metadata report for BODC series reference number 1052258
10522712009-11-23 09:30:28 58° 59' 58" S  55° 51' 23" W  View metadata report for BODC series reference number 1052271
10522832009-11-23 14:09:32 59° 19' 58" S  55° 39' 1" W  View metadata report for BODC series reference number 1052283
10522952009-11-23 18:44:25 59° 39' 59" S  55° 26' 39" W  View metadata report for BODC series reference number 1052295
10523022009-11-23 23:18:34 59° 59' 58" S  55° 14' 16" W  View metadata report for BODC series reference number 1052302
10523142009-11-24 04:02:51 60° 19' 59" S  55° 1' 52" W  View metadata report for BODC series reference number 1052314
10523262009-11-24 08:22:40 60° 39' 57" S  54° 49' 28" W  View metadata report for BODC series reference number 1052326
10523382009-11-24 18:55:36 60° 47' 59" S  54° 44' 31" W  View metadata report for BODC series reference number 1052338
10523512009-11-24 22:30:16 60° 49' 59" S  54° 43' 10" W  View metadata report for BODC series reference number 1052351
10523632009-11-25 01:17:37 60° 51' 0" S  54° 42' 39" W  View metadata report for BODC series reference number 1052363
10523752009-11-25 04:32:14 60° 58' 39" S  54° 38' 1" W  View metadata report for BODC series reference number 1052375
10523872009-11-25 06:37:41 61° 3' 3" S  54° 35' 28" W  View metadata report for BODC series reference number 1052387
10523992009-11-26 00:01:48 60° 50' 5" S  54° 36' 23" W  View metadata report for BODC series reference number 1052399
10524062009-11-26 01:09:51 60° 50' 21" S  54° 36' 0" W  View metadata report for BODC series reference number 1052406
10524182009-11-18 13:53:01 52° 14' 49" S  57° 49' 9" W  View metadata report for BODC series reference number 1052418
10524312009-11-18 21:26:05 53° 30' 25" S  58° 10' 53" W  View metadata report for BODC series reference number 1052431