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BODC Cruise Metadata Report for RRS Discovery (74E3) cruise D361 (GA06)

Introduction

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

Cruise Inventory Information

Long name RRS Discovery (74E3) cruise D361 (GA06)
Short name D361 (GA06)
Objectives and Narrative The cruise D361 forms part of a study entitled 'Physical and chemical forcing of diazotrophy in the (sub)-tropical Atlantic Ocean'. The study is investigating the potential influence of iron and phosphorus availability on nitrogen fixation in regions of the tropical Atlantic Ocean. The cruise also undertakes deep trace metal clean CTD casts as part of the International GEOTRACES programme. The purpose of the cruise therefore is to undertake measurements of dissolved and particulate iron and phosporpus availability, their spatial and temporal variations, and their impact on diazotrophy in the surface ocean.

Aim: To quantify the supply and determine the biogeochemical cycling of Fe and other nutrients, and relate this to N2 fixation, diazotroph species distribution and N* fields.
1. Quantify the distribution of nutrients and trace metals: Quantify surface water and water column distributions of dissolved inorganic/organic N, P, Fe, and DAl, DMn and particulate P, N, Fe, Al, Mn.
2. Quantify the rate of Fe, Al, Mn, P and N supply to surface waters: Assess the source fluxes of the key elements for diazotrophs and source tracers to the surface ocean from atmospheric deposition and internal transport via diapycnal mixing and lateral advection.
3. Identify the source of subsurface Fe enrichment: Identify whether Fe-rich subsurface waters of the tropical North Atlantic thermocline originate from the atmosphere or the shelf using Fe distributions and Al, Mn, and O2 source tracers.
4. Quantify the diazotrophic response to Fe, phosphate, DOP supply: Relate the spatial distributions of inorganic Fe and organically complexed Fe, and phosphate and DOP to diazotrophy. The specific uptake of Fe, phosphate and DOP by the whole microbial community and Trichodesmium will be assessed by shipboard incubations, radiotracer techniques and enzyme bioassays. In addition, we will identify the connection between N2 fixation rates and diazotroph community structure, by comparing size fractionated 15N2-derived rates of N2 fixation (Fig. 1) with abundance and diversity of diazotrophs using nifH phylogeny.
Objective 5: Investigate how the large scale transport pathways of Fe and P influence the N* distribution: Use fine-scale isopycnic model to reveal the large-scale transport pathways of Fe and P in the (S)-T Atlantic, and their effect on the N* distribution.
Ship RRS Discovery
Departure Port Santa Cruz de Tenerife, Spain
Departure Date 2011-02-07
Arrival Port Santa Cruz de Tenerife, Spain
Arrival Date 2011-03-19
Principal Scientist(s) Eric Pieter Achterberg (University of Southampton School of Ocean and Earth Science)
Responsible Organisation Polytechnic South West Institute of Marine Studies
Associated Project(s) GEOTRACES
IHB Sea Areas Visited North East Atlantic Ocean (limit 40W), South Atlantic Ocean
Marsden Squares Visited 110/111/181/182/3/301/302/38/39/4/40/75/76
Work Area Description Tropical North and South Atlantic Ocean
Work Area Bounding Polygon 10S,40W; 60N,40W; 60N,0E; 10S,0E; 10S,40W
Southern Limit 10S
Northern Limit 60N
Western Limit 40W
Eastern Limit 0E

Cruise Inventory Datasets

Physical oceanography  
CTD stations Quantity: number of profiles = 8
Description: 7 + 1test CTD stations for Th-234 measurements. 6 Shallow (500 m) and two deep CTD profiles (1000m) were sampled  
CTD stations Quantity: number of profiles = 40
Description: 21 Stainless steel; 19 titanium CTD profiles. Shallow (500 m) and full depth.  
Current profiler (eg ADCP) Quantity: track kilometres = 8000
Description: Vessel mounted ADCP (75kHz)  
Other physical oceanographic measurements Quantity: number of profiles = 15
Description: Turbulence profiler  
Subsurface temperature and salinity measurements Quantity: track kilometres = 8000
Description: Ship fitted underway data (surface temperature, salinity, fluorescence and transmissivity, bathymetry). Ship fitted meterological instruments (wind speed/direction incident light, PAR etc)  
Chemical oceanography  
Alkalinity Quantity: number of stations = 37
Description: CTD Vertical profiles: Dissolved Inorganic Carbon, Dissolved Organic Carbon, Alkalinity  
Alkalinity Quantity: number of samples = 128
Description: Alkalinity Underway samples  
Carbon dioxide Quantity: number of stations = 37
Description: CTD Vertical profiles: Dissolved Inorganic Carbon, Dissolved Organic Carbon, Alkalinity  
Carbon dioxide Quantity: activity duration in days = 25
Description: Dissolved Inorganic Carbon Automated underway samples  
Nitrate Quantity: number of stations = 42
Description: Micromolar Nutrients CTD Vertical profiles  
Nitrite Quantity: number of stations = 42
Description: Micromolar Nutrients CTD Vertical profiles  
Other chemical oceanographic measurements Quantity: number of samples = 114
Description: Rates of alkaline phosphatase activity were determined from water samples taken from 6 depths from the stainless steel CTD (114 rate measurements). Rates were determined by the change in fluoresence of the substrate MUFP and calibrated using the standard MUF. Fluoresence was determined using a Turner 10Au field fluorometer. Rates were determined onboard by Claire Mahaffey  
Other chemical oceanographic measurements Quantity: number of samples = 114
Description: Samples collected from the stainless steel rosette and FISH for 33phosphate uptake rates of the bulk community. Incubations conducted on board by Sarah Reynolds  
Other chemical oceanographic measurements Quantity: number of samples = 18
Description: Trichodesmium colonies were collected from plankton nets deployed in the upper 30m of the water column. 10-20 Trichodesmium colonies were placed in filtered or unfiltered seawater and rates of 33P-phosphate and alkaline phosphatase activity.  
Other chemical oceanographic measurements Quantity: number of samples = 111
Description: Unfiltered seawater samples were collected and analysed on board for the determination of hydrogen peroxide using Flow Injection with Chemiluminescence detection.  
Oxygen Quantity: number of stations = 21
Description: Dissolved oxygen (Ámol l-1) discrete samples from vertical profiles - stainless steel (10depths) and titanium rosettes (4-16 depths). Analysed onboard using PC-controlled potentiometric system and modified Winkler method.  
Phosphate Quantity: number of stations = 42
Description: Micromolar Nutrients CTD Vertical profiles  
Phosphate Quantity: number of samples = 224
Description: Surface sampling Fish underway samples  
Silicate Quantity: number of stations = 42
Description: Micromolar Nutrients CTD Vertical profiles  
Trace elements Quantity: number of samples = 180
Description: Unfiltered seawater for total dissolvable trace metal measurements was collected from the Titanium Rosette. Samples will be analysed after a minimum of 4 months at the National Oceanography Centre, Southampton by Isotope Dilution-ICPMS  
Trace elements Quantity: number of samples = 369
Description: Filtered seawater samples for determination of dissolved aluminium and iron (dAl (H) and dFe (G)) collected from the Titanium Rosette. Samples have been analysed on board using Flow Injection Analysis.  
Trace elements Quantity: number of samples = 213
Description: Filtered seawater samples for the detemination of dAl (H), dFe (G) and dissolved trace metals (I) were collected from the underway fish along the cruise track. Samples for dAl and dFe were analysed on board using Flow Injection Analysis. Dissolved trace metals will be analysed at the National Oceanography Centre, Southampton by Isotope Dilution-ICPMS  
Trace elements Quantity: number of samples = 50
Description: Filtered seawater samples for iron isotopes collected from the trace metal OTE bottles deployed on the Titanium Rosette. Samples will be analysed using ICP-MS at the University of Southampton.  
Trace elements Quantity: number of samples = 50
Description: 0.4 Ám filtered seawater for iron ligands was collected from the Titanium Rosette. Samples were stored frozen (-20C) for analysis at the National Oceanography Centre, Southampton by Competitive Ligand Exchange-Cathodic Stripping Voltammetry.  
Trace elements Quantity: number of samples = 57
Description: Unfiltered seawater samples were collected and analysed on board for dissolved Fe(II) using Flow Injection with Chemiluminescence detection.  
Trace elements Quantity: number of samples = 115
Description: Unfiltered seawater for total dissolvable trace metal measurements was collected from the underway fish along the cruise track. Samples will be analysed after a minimum of 4 months at the National Oceanography Centre, Southampton by Isotope Dilution-ICPMS  
Trace elements Quantity: number of samples = 368
Description: Filtered seawater samples for determination of total dissolved cobalt collected from the Titanium Rosette. Samples will be determined using Flow Injection Analysis at the University of Plymouth  
Trace elements Quantity: number of samples = 371
Description: Particulate samples collected on PES filters from the trace metal OTE bottles deployed on the Titanium Rosette. Samples will be analysed using ICP-MS at the university of Plymouth.  
Trace elements Quantity: number of samples = 200
Description: Filtered seawater samples for the detemination of total dissolved cobalt were collected from the underway fish along the cruise track. Samples will be determined using Flow Injection Analysis at the University of Plymouth  
pH Quantity: number of samples = 360
Description: pH Underway samples  
Biology and fisheries  
Biochemical measurements (eg lipids, amino acids) Quantity: number of samples = 116
Description: Filtered seawater samples for proteomic analyses were collected from the stainless steel CTD (0-1000m, 81 samples), and the SAPS deployments (60-500m, 35 samples). Samples will be analysed by Elizabeth Sargent at the National Oceanography Centre, Southampton  
Biochemical measurements (eg lipids, amino acids) Quantity: number of samples = 127
Description: Seawater samples from the stainless CTD were filtered onto GF/Fs to measure heme b concentration. Filters will be analysed using high performance liquid chromatography with diode array spectrophotometry. Samples were also collected from the continuous FISH supply (79 more samples).  
Dissolved organic matter (inc DOC) Quantity: number of stations = 37
Description: CTD Vertical profiles: Dissolved Inorganic Carbon, Dissolved Organic Carbon, Alkalinity  
Dissolved organic matter (inc DOC) Quantity: number of samples = 343
Description: Filtered seawater samples for the determination of dissolved organic phosphorus collected from the stainless steel (0-500m, 183 samples) and titanium rosette (below 500m, 133 samples). Samples will be determined by UV digestion and subsequent phosphate analysis by Sarah Reynolds and Claire Mahaffey at the University of Liverpool. Samples were also collected from the FISH (37 samples).  
Dissolved organic matter (inc DOC) Quantity: number of samples = 167
Description: Filtered seawater samples for the determination of enzyme hydrolysable phosphorus collected from the stainless steel rosette (0-500m, 183 samples). Samples will be determined by enzyme assays by Sarah Reynolds and Claire Mahaffey at the University of Liverpool. Samples were also collected from the FISH (37 samples).  
Other biological/fisheries measurement Quantity: number of samples = 91
Description: Seawater samples from the stainless CTD were used to measure in situ nitrogen fixation rates. Samples were 'spiked' with 15N2 gas and incubated for 24 hours. Samples were then filtered onto pre-ashed GF/Fs and dried for a further 24 hours. Samples will be analysed using mass spectrometry.  
Other biological/fisheries measurement Quantity: number of stations = 20
Description: Water samples were collected for the estimation of whole microbial community iron uptake using a 55Fe tracer technique. Water was collected from the underway trace clean metal fish. Incubations were performed over 10-12 hours.  
Other biological/fisheries measurement Quantity: number of stations = 12
Description: Samples of trichodesimum were collected using net hauls for the estimation of colony specific iron uptake using a 55Fe tracer technique. Colonies were picked and rinsed 3 times in filtered trace clean seawater collected from the underway trace clean metal fish. Incubations were then performed over 10-12 hours in seawater collected in the same manner.  
Particulate organic matter (inc POC, PON) Quantity: number of samples = 137
Description: Seawater samples from the stainless CTD were filtered onto pre-ashed GF/Fs to measure POC/PON/15N tzero. Filters will be analysed using mass spectrometry. Samples were also collected from the continuous FISH supply (78 more samples).  
Particulate organic matter (inc POC, PON) Quantity: number of samples = 311
Description: Incubations with 15N2 and H13CO3 to measure uptake of inorganic carbon and dinitrogen by the phytoplankton and bacterial community  
Particulate organic matter (inc POC, PON) Quantity: number of samples = 114
Description: Filter samples for the determination of particulate phosphorus were collected from the stainless steel rosette. Concentrations will be determined by high temperature combustion and acid hydrolysis and subsequent phosphate analysis by Sarah Reynolds and Claire Mahaffey at the University of Liverpool.  
Particulate organic matter (inc POC, PON) Quantity: number of deployments = 8
Description: 7 + 1test SAPS deployments, 53 and 1 micron mesh sizes x 3 depths (up to 500m) for POC, PON, BSi and PIC analyses.  
Pelagic bacteria/micro-organisms Quantity: number of samples = 352
Description: Filters of 0.2Ám filtered seawater to assess the community diversity and abundance of the nifH gene (a marker gene for nitrogen fixation).  
Pelagic bacteria/micro-organisms Quantity: number of hauls = 37
Description: Collected Trichodesmium colonies from plankton net hauls, each haul included 2 or 3 nets on the same line and were either 20 Ám or 100 Ám mesh nets. Picked Trichodesmium colonies were filtered onto suitable filters and frozen for analysis back at NOCS. Analysis will aim to relate the mRNA expression with the stoichiometric elemental composition.  
Phytoplankton Quantity: number of samples = 106
Description: Whole water samples that were collected from the stainless steel CTD (0-500m, 63 samples) and the marine snow catcher (35-100m, 13 samples), and concentrated samples that were collected from the nets (30 samples) were preserved in lugol's iodine for phytoplankton community assessments. Assessments will be carried out by Elizabeth Sargent at the National Oceanography Centre, Southampton.  
Phytoplankton pigs (eg chlorophyll, fluorescence) Quantity: number of samples = 147
Description: Seawater samples from the stainless CTD were filtered onto GF/Fs to measure chlorophyll a concentration. Filters were submerged in 90% acetone for 24 hours and analysed onboard using a fluorometer. Samples were also collected from the continuous towed FISH supply (200 more samples).  
Phytoplankton pigs (eg chlorophyll, fluorescence) Quantity: activity duration in days = 27
Description: Continuous fluorescence data collected using a Chelsea Scientific instruments FASTtrackTM Fast Repetition Rate fluorometer (FRRf) that was attached to the ships non-toxic underway system.  
Primary productivity Quantity: number of samples = 311
Description: Incubations with 15N2 and H13CO3 to measure uptake of inorganic carbon and dinitrogen by the phytoplankton and bacterial community  
Meteorology  
Atmospheric chemistry Quantity: number of samples = 7
Description: Rainwater samples for determination of trace metal and major ion concentrations upon return to the UK.  
Atmospheric chemistry Quantity: number of samples = 78
Description: High volume aerosol samples (1 m3 min-1) for determination of trace metals (TM), major ions (MI) and metal isotopes (ISO) upon return to the UK. TM and MI samples were size segregated using a cascade impactor, ISO samples were bulk only. To avoid contamination from the ships funnel, a wind sector controller was used to ensure samples were only collected when the relative wind direction was from the bows.  
Routine standard measurements Quantity: track kilometres = 8000
Description: Ship fitted underway data (surface temperature, salinity, fluorescence and transmissivity, bathymetry). Ship fitted meterological instruments (wind speed/direction incident light, PAR etc)  

Cruise Inventory Mooring/Buoy Operations

No information on datasets is currently available

Summary of BODC Data Holdings for the Cruise

National Oceanographic Database

Summary

# Series Instrument Description Parameters
47 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
Transmittance and attenuance 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  
1057619 CTD/STD cast 2011-02-15 09:58Z to 2011-02-15 10:14Z 28° 18' N, 16° 7' W Click for more
1057620 CTD/STD cast 2011-02-16 09:52Z to 2011-02-16 10:51Z 28° 19' N, 16° 7' W Click for more
1057632 CTD/STD cast 2011-02-17 14:16Z to 2011-02-17 14:30Z 28° 14' N, 16° 12' W Click for more
1057644 CTD/STD cast 2011-02-18 09:54Z to 2011-02-18 10:11Z 27° 46' N, 16° 13' W Click for more
1057656 CTD/STD cast 2011-02-22 00:46Z to 2011-02-22 01:04Z 12° 35' N, 17° 54' W Click for more
1057668 CTD/STD cast 2011-02-22 02:18Z to 2011-02-22 03:21Z 12° 35' N, 17° 55' W Click for more
1057681 CTD/STD cast 2011-02-22 07:02Z to 2011-02-22 07:17Z 12° 35' N, 17° 42' W Click for more
1057693 CTD/STD cast 2011-02-22 11:51Z to 2011-02-22 12:16Z 12° 36' N, 17° 43' W Click for more
1057700 CTD/STD cast 2011-02-22 16:50Z to 2011-02-22 17:00Z 12° 35' N, 17° 34' W Click for more
1057712 CTD/STD cast 2011-02-22 19:50Z to 2011-02-22 19:55Z 12° 36' N, 17° 34' W Click for more
1057724 CTD/STD cast 2011-02-22 20:32Z to 2011-02-22 20:35Z 12° 36' N, 17° 34' W Click for more
1057736 CTD/STD cast 2011-02-22 21:24Z to 2011-02-22 21:28Z 12° 35' N, 17° 34' W Click for more
1057748 CTD/STD cast 2011-02-23 05:34Z to 2011-02-23 05:48Z 12° 34' N, 18° 49' W Click for more
1057761 CTD/STD cast 2011-02-23 07:05Z to 2011-02-23 08:36Z 12° 33' N, 18° 49' W Click for more
1057773 CTD/STD cast 2011-02-24 06:42Z to 2011-02-24 06:58Z 12° 34' N, 21° 49' W Click for more
1057785 CTD/STD cast 2011-02-24 12:49Z to 2011-02-24 14:13Z 12° 34' N, 21° 49' W Click for more
1057797 CTD/STD cast 2011-02-25 06:38Z to 2011-02-25 06:54Z 12° 34' N, 23° 33' W Click for more
1057804 CTD/STD cast 2011-02-25 08:09Z to 2011-02-25 09:50Z 12° 35' N, 23° 33' W Click for more
1057816 CTD/STD cast 2011-02-25 16:14Z to 2011-02-25 16:42Z 12° 35' N, 23° 34' W Click for more
1057828 CTD/STD cast 2011-02-26 06:35Z to 2011-02-26 06:51Z 12° 18' N, 25° 7' W Click for more
1057841 CTD/STD cast 2011-02-26 08:09Z to 2011-02-26 09:56Z 12° 18' N, 25° 9' W Click for more
1057853 CTD/STD cast 2011-03-03 15:00Z to 2011-03-03 15:20Z 7° 13' S, 24° 59' W Click for more
1057865 CTD/STD cast 2011-03-03 16:41Z to 2011-03-03 18:38Z 7° 13' S, 25° 0' W Click for more
1057877 CTD/STD cast 2011-03-04 03:39Z to 2011-03-04 03:57Z 7° 13' S, 24° 59' W Click for more
1057889 CTD/STD cast 2011-03-05 06:36Z to 2011-03-05 06:50Z 3° 15' S, 25° 31' W Click for more
1057890 CTD/STD cast 2011-03-05 07:51Z to 2011-03-05 09:40Z 3° 15' S, 25° 32' W Click for more
1057908 CTD/STD cast 2011-03-05 16:44Z to 2011-03-05 17:25Z 2° 57' S, 25° 36' W Click for more
1057921 CTD/STD cast 2011-03-06 06:41Z to 2011-03-06 06:53Z 1° 10' S, 25° 47' W Click for more
1057933 CTD/STD cast 2011-03-06 08:02Z to 2011-03-06 09:58Z 1° 9' S, 25° 48' W Click for more
1057945 CTD/STD cast 2011-03-07 06:37Z to 2011-03-07 06:51Z 1° 9' N, 26° 3' W Click for more
1057957 CTD/STD cast 2011-03-07 07:50Z to 2011-03-07 09:04Z 1° 9' N, 26° 3' W Click for more
1057969 CTD/STD cast 2011-03-08 06:35Z to 2011-03-08 06:51Z 3° 19' N, 26° 48' W Click for more
1057970 CTD/STD cast 2011-03-08 07:51Z to 2011-03-08 09:26Z 3° 21' N, 26° 49' W Click for more
1057982 CTD/STD cast 2011-03-09 06:35Z to 2011-03-09 06:54Z 5° 39' N, 27° 30' W Click for more
1057994 CTD/STD cast 2011-03-09 07:56Z to 2011-03-09 09:11Z 5° 40' N, 27° 30' W Click for more
1058008 CTD/STD cast 2011-03-10 06:35Z to 2011-03-10 06:48Z 8° 20' N, 28° 19' W Click for more
1058021 CTD/STD cast 2011-03-10 07:52Z to 2011-03-10 09:31Z 8° 21' N, 28° 20' W Click for more
1058033 CTD/STD cast 2011-03-11 06:33Z to 2011-03-11 06:48Z 10° 37' N, 28° 43' W Click for more
1058045 CTD/STD cast 2011-03-11 07:53Z to 2011-03-11 09:44Z 10° 37' N, 28° 43' W Click for more
1058057 CTD/STD cast 2011-03-12 02:07Z to 2011-03-12 04:00Z 12° 1' N, 28° 58' W Click for more
1058069 CTD/STD cast 2011-03-12 07:15Z to 2011-03-12 07:30Z 12° 3' N, 28° 58' W Click for more
1058070 CTD/STD cast 2011-03-13 06:35Z to 2011-03-13 06:49Z 15° 30' N, 28° 47' W Click for more
1058082 CTD/STD cast 2011-03-13 07:47Z to 2011-03-13 09:19Z 15° 30' N, 28° 47' W Click for more
1058094 CTD/STD cast 2011-03-14 07:03Z to 2011-03-14 07:14Z 17° 24' N, 28° 23' W Click for more
1058101 CTD/STD cast 2011-03-14 13:44Z to 2011-03-14 15:39Z 17° 25' N, 28° 23' W Click for more
1058113 CTD/STD cast 2011-03-15 06:39Z to 2011-03-15 07:03Z 19° 7' N, 28° 7' W Click for more
1058125 CTD/STD cast 2011-03-15 10:11Z to 2011-03-15 10:34Z 19° 10' N, 28° 7' W Click for more

Project Database

# Events Gear Type Parameters Held
27 No parameter data available
22 CTD frame plus rosette sampler Dissolved total and organic nitrogen concentrations in the water column
Radioactivity in water bodies
Alkalinity, acidity and pH of the water column
Silicate concentration parameters in the water column
Salinity of the water column
Dissolved organic carbon concentration in the water column
Nitrate concentration parameters in the water column
Total dissolved inorganic carbon (TCO2) concentration in the water column
Temperature of the water column
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
Dissolved oxygen parameters in the water column
6 Rain water collector Precipitation chemistry
234 All plastic clean surface pumped supply Dissolved metal concentrations in the water column

Radioactivity in water bodies
Silicate concentration parameters in the water column
Nitrate concentration parameters in the water column
Concentration of inorganic halogens in water bodies
Nitrite concentration parameters in the water column
Phosphate concentration parameters in the water column
24 Atmospheric air sampling pump Metal concentrations in the atmosphere
Concentration of inorganic halogens in the atmosphere
Concentration of nitrogen species in the atmosphere
Sulphur species concentrations in the atmosphere

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

References

Track Charts

No track charts currently available

Reports

Cruise Report