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BODC Cruise Metadata Report for RRS James Clark Ross (74JC) cruise JR20091118 (JR195, JR198)

Introduction

This report collates information from the BODC cruise inventory and oceanographic databases. It presents

Cruise Inventory Information

Long name RRS James Clark Ross (74JC) cruise JR20091118 (JR195, JR198)
Short name JR20091118 (JR195, JR198)
Objectives and Narrative The 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.
Ship RRS James Clark Ross
Departure Port Stanley, Falkland Islands (Malvinas)
Departure Date 2009-11-18
Arrival Port Rothera, Antarctica
Arrival Date 2009-11-27
Principal Scientist(s) Margaret J Yelland (National Oceanography Centre, Southampton)
Responsible Organisation National Marine Facilities Sea Systems, Polar Res. Ins. of Mar. Fisheries + Ocean. Russia
Associated Project(s) ACCLAIM (Antarctic Circumpolar Current Levels by Altimetry and Islands Measurements)
IHB Sea Areas Visited Southern Ocean
Marsden Squares Visited 486/522
Work Area Description Drake Passage
Work Area Bounding Polygon 70S,70W; 50S,70W; 50S,60W; 70S,60W; 70S,70W
Southern Limit 70S
Northern Limit 50S
Western Limit 70W
Eastern Limit 60W

Cruise Inventory Datasets

Physical oceanography  
CTD stations 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  
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.  
Other physical oceanographic measurements Quantity: 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.  
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  
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.  
Water bottle stations Quantity: number of samples = 228
Description: Bottle salinity samples collected with rosette sampler analysed by bench salinometer  
Chemical oceanography  
Oxygen 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.  
Biology and fisheries  
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).  
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.  
Meteorology  
Incident radiation Quantity: activity duration in days = 12
Description: short wave radiation (TIR), photosynthetically active radiation (PAR)  
Other meteorological measurements Quantity: 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 echosounding Quantity: activity duration in days = 12
Description: Bathymetry by a Kongsberg EA600 single beam echo sounder  

Cruise Inventory Mooring/Buoy Operations

Latitude Longitude Data type Description
60° 37' S 53° 49' W Sea level (inc. bot. press., inverted echosounder) MYRTLE Site: unsuccessful attempt a recovering a MYRTLE capsule and, subsequently, the MYRTLE frame, depth ~2800 m , 24/11/09, 12:59Z-16:06Z
57° 52' S 56° 31' W Sea level (inc. bot. press., inverted echosounder) Site Drake Middle: Bottom Pressure Recorder with microCAT, deployed in 2008, recovered from ~4000m, 22/11/09, 20:56Z
54° 56' S 58° 21' W Sea level (inc. bot. press., inverted echosounder) Site Drake North: Bottom Pressure Recorder with microCAT, deployed to ~1000 m, 19/11/09, 15:02Z
54° 57' S 58° 21' W Sea level (inc. bot. press., inverted echosounder) Site Drake North: Easterly Bottom Pressure Recorder with microCAT deployed in 2008, recovered from ~1000 m, 19/11/09, 13:19Z
54° 57' S 58° 22' W Sea level (inc. bot. press., inverted echosounder) Site Drake North: Westerly Bottom Pressure Recorder deployed in 2007, recovered from ~1000 m, 19/11/09, 14:44Z
60° 49' S 54° 43' W Sea level (inc. bot. press., inverted echosounder) Site Drake South deep: Bottom Pressure Recorder with microCAT, deployed to ~2000 m, 24/11/09, 21:21Z
60° 51' S 54° 42' W Sea level (inc. bot. press., inverted echosounder) Site Drake South shallow: Bottom Pressure Recorder deployed to ~1000 m, 25/11/09, 01:06Z
60° 51' S 54° 42' W Sea level (inc. bot. press., inverted echosounder) Site Drake South: Bottom Pressure Recorder deployed in 2007, recovered from ~1000 m, 25/11/09, 00:53Z

Summary of BODC Data Holdings for the Cruise

National Oceanographic Database

Summary

# Series Instrument Description Parameters
33 CTD/STD cast Chlorophyll pigment concentrations in water bodies
Density of the water column
Dissolved oxygen parameters in the water column
Electrical conductivity of the water column
Reference numbers
Salinity of the water column
Temperature of the water column
Vertical spatial coordinates

Note: Parameter terms are taken from the BODC Parameter Discovery Vocabulary XML (SKOS)

Full List

BODC Reference Instrument Description Date/Time Location  
1052074 CTD/STD cast 2009-11-19 05:23Z 54° 40' S, 58° 32' W Click for more
1052086 CTD/STD cast 2009-11-19 07:47Z 54° 55' S, 58° 22' W Click for more
1052098 CTD/STD cast 2009-11-19 09:05Z 54° 56' S, 58° 22' W Click for more
1052105 CTD/STD cast 2009-11-19 10:35Z 54° 57' S, 58° 21' W Click for more
1052117 CTD/STD cast 2009-11-19 16:41Z 55° 4' S, 58° 16' W Click for more
1052129 CTD/STD cast 2009-11-19 18:52Z 55° 7' S, 58° 14' W Click for more
1052130 CTD/STD cast 2009-11-19 21:45Z 55° 10' S, 58° 12' W Click for more
1052142 CTD/STD cast 2009-11-21 02:20Z 55° 22' S, 58° 6' W Click for more
1052154 CTD/STD cast 2009-11-21 08:19Z 55° 49' S, 57° 49' W Click for more
1052166 CTD/STD cast 2009-11-21 13:49Z 56° 9' S, 57° 37' W Click for more
1052178 CTD/STD cast 2009-11-21 18:08Z 56° 28' S, 57° 25' W Click for more
1052191 CTD/STD cast 2009-11-21 22:42Z 56° 46' S, 57° 13' W Click for more
1052209 CTD/STD cast 2009-11-22 03:20Z 57° 6' S, 57° 1' W Click for more
1052210 CTD/STD cast 2009-11-22 08:11Z 57° 25' S, 56° 49' W Click for more
1052222 CTD/STD cast 2009-11-22 12:42Z 57° 43' S, 56° 38' W Click for more
1052234 CTD/STD cast 2009-11-22 16:20Z 57° 54' S, 56° 32' W Click for more
1052246 CTD/STD cast 2009-11-23 00:06Z 58° 22' S, 56° 15' W Click for more
1052258 CTD/STD cast 2009-11-23 04:53Z 58° 40' S, 56° 3' W Click for more
1052271 CTD/STD cast 2009-11-23 09:30Z 59° 0' S, 55° 51' W Click for more
1052283 CTD/STD cast 2009-11-23 14:09Z 59° 19' S, 55° 39' W Click for more
1052295 CTD/STD cast 2009-11-23 18:44Z 59° 40' S, 55° 26' W Click for more
1052302 CTD/STD cast 2009-11-23 23:18Z 60° 0' S, 55° 14' W Click for more
1052314 CTD/STD cast 2009-11-24 04:02Z 60° 19' S, 55° 1' W Click for more
1052326 CTD/STD cast 2009-11-24 08:22Z 60° 40' S, 54° 49' W Click for more
1052338 CTD/STD cast 2009-11-24 18:55Z 60° 48' S, 54° 44' W Click for more
1052351 CTD/STD cast 2009-11-24 22:30Z 60° 49' S, 54° 43' W Click for more
1052363 CTD/STD cast 2009-11-25 01:17Z 60° 51' S, 54° 42' W Click for more
1052375 CTD/STD cast 2009-11-25 04:32Z 60° 58' S, 54° 37' W Click for more
1052387 CTD/STD cast 2009-11-25 06:37Z 61° 3' S, 54° 35' W Click for more
1052399 CTD/STD cast 2009-11-26 00:01Z 60° 49' S, 54° 36' W Click for more
1052406 CTD/STD cast 2009-11-26 01:09Z 60° 50' S, 54° 36' W Click for more
1052418 CTD/STD cast 2009-11-18 13:53Z 52° 15' S, 57° 49' W Click for more
1052431 CTD/STD cast 2009-11-18 21:26Z 53° 30' S, 58° 10' W Click for more

Project Database

No data currently held for this cruise in the BODC Project Database

References

Track Charts

Track Chart

Reports

Cruise Report