CRUISE REPORT: AR07 (Updated NOV 2019) HIGHLIGHTS CRUISE SUMMARY INFORMATION Section Designation AR07 Expedition designation (ExpoCodes) 74JC20140606 Chief Scientists B.A. King/NOC and N.P. Holliday/NOC Dates 2014 JUN 06 – 2014 JUL 21 Ship RRS James Clark Ross Ports of call St Johns, Newfoundland, Canada to Immingham, UK, 63°19.02' N Geographic Boundaries 55°33.91' W 6°7.98' W 52°0' N Stations 280 CTD Stations Floats and drifters deployed 8 Argo floats deployed Moorings deployed or recovered 0 Contact Information: N.P. Holliday National Oceanography Centre, Southampton University of Southampton Waterfront Campus European Way • Southampton Hants SO14 3ZH UK Tel: +44 (0)23 8059 6206 • Email: penny.holliday@noc.ac.uk Final report assembly by Jerry Kappa, SIO/UCSD National Oceanography Centre Natural Environment Research Council National Oceanography Centre Cruise Report No. 35 RRS James Clark Ross Cruise 302 06 JUN - 21 JUL 2014 The 2015 RAGNARRoC, OSNAP and Extended Ellett Line cruise report Principal Scientists B A King and N P Holliday 2015 National Oceanography Centre, Southampton University of Southampton Waterfront Campus European Way Southampton Hants SO14 3ZH UK Tel: +44 (0)23 8059 6206 Email: penny.holliday@noc.ac.uk © National Oceanography Centre, 2015 DOCUMENT DATA SHEET AUTHOR PUBLICATION KING, B A & HOLLIDAY, N P et al DATE 2015 TITLE RRS James Clark Ross Cruise 302, 06 Jun - 21 Jul 2014, The 2015 RAGNARRoC, OSNAP AND Extended Ellett Line cruise report REFERENCE Southampton, UK: National Oceanography Centre, Southampton, 76pp. (National Oceanography Centre Cruise Report, No. 35) ABSTRACT Cruise JR302 was an NERC-NC funded cruise aiming to complete a full CTD section across the subpolar gyre, from Canada to Greenland to Scotland. The CTD section was located along the OSNAP track (www.ukosnap.org), providing a high quality and high resolution synoptic survey for the start of that programme. The objectives included a full suite of biogeochemistry measurements under the RAGNARRoC programmes. Finally, the eastern part of the section included the 2014 occupation of the Extended Ellett Line (projects.noc.ac.uk/ExtendedEllettLine) between Scotland and Iceland. Additional sections were made around the Cape Farewell region with the objective of measuring transport and the movement of water away from the boundary currents. Additional objectives included deploying eight Met Office Argo floats, and recovering one SAMS glider. Two new instruments were trialled by deploying them on the CTD frame; the IMP and RBR. All objectives were successfully completed. KEYWORDS ISSUING ORGANISATION National Oceanography Centre University of Southampton Waterfront Campus European Way Southampton SO14 3ZH UK Tel: +44(0)23 80596116 Email: nol@noc.soton.ac.uk A pdf of this report is available for download at: http://eprints.soton.ac.uk Contents Scientific Personnel Ship's Personnel 1. Overview 1.1 Itinerary 1.2 Objectives 2. Profile Measurements 2.1 CTD Sensors 2.2 CTD Data processing 2.3 CTD calibrations 2.3.1 Oxygen 2.3.2 Salinity 2.4 LADCP 2.4.1 Instrument technical details 2.4.2 Data Processing 2.4.3 IMP 2.5 RBR Concerto CTD 3. Water Sample Measurements 3.1 Salinity 3.2 Dissolved Oxygen 3.3 Total Dissolved and Dissolved Inorganic Nutrients 3.4 Carbonate system measurements 3.5 CFCs 3.6 Methane and Nitrous Oxide 3.7 Surfactants, CDOM and Pigments 3.8 Trace Metals 3.9 Phytoplankton community structure and species identification 3.10 Iodine Isotope sampling 4. Underway Measurements 4.1 SCS data streams 4.2 VMADCP 4.3 Pumped seawater: underway carbon 5. Autonomous Platforms 5.1 Floats 5.2 Seaglider 6. Outreach CCHDO Data Processing Notes Scientific Personnel Ian Brown PML Jen Clarke NOC/Southampton University PhD student Damien Desbruyeres NOC Hannah Donald NOC/Southampton University PhD student Andy England BAS Claudia Fry NOC/Southampton University PhD student Becky Garley Bermuda Stefan Gary SAMS Carolyn Graves NOC/Southampton University PhD student Alex Griffiths NOC Lilo Henke Exeter University PhD student Penny Holliday NOC Brian King NOC Jonathan Lawrence NOC/Southampton University PhD student Peter Mead Exeter University Marie-Jose Messias Exeter University Gary Murphy Exeter University Bita Sabbaghzadeh Newcastle University Mark Stinchcombe NOC Seth Thomas BAS Sinhue Torres Valdes NOC Tobia Tudino Exeter University PhD student Eithne Tynan Southampton University Felicity Williams NOC/Southampton University PhD student John Wynar NOC Ship's Personnel CHAPMAN Graham P Master EVANS Simon D Ch Officer HIPSEY Christopher W 2nd Officer DELPH Georgina M 3rd Off WADDICOR Charles A ETO (Coms) PARNELL Luke T Ch Eng COLLARD Glynn 2nd Eng HARDY Aleksandr J 3rd Eng EADIE Steven J 4th Eng WRIGHT Simon A Deck Eng DUNBAR Nicholas J ETO (Eng) KLEPACKI Julian Suppny ETO GIBSON James S Purser MULLANEY Clifford Bosun SciOps O'DUFFY John P Bosun LEGGETT Colin J SG1 DYER Martyn P SG1 PHELPS Kenneth J SG1 WAYLETT Graham L SG1 BELL Shaun SG1 FAULKNER Leslie J SG1 WILSON Paul S MG1 HERBERT Ian B MG1 WALKER Keith A Cook MOLLOY Padraig G 2nd Cook WESTON Kenneth Sr Stwd NEWALL James Stwd LEE Derek W Stwd PATTERSON Thomas R Stwd 1. OVERVIEW 1.1 Itinerary St Johns, Newfoundland, Canada to Immingham, UK, 6 Jun - 21 Jul 2014 Figure 1.1.1: The JR302 station positions and track line Figure 1.1.2: Station positions and numbers for the OSNAP West line Figure 1.1.3: Station positions and numbers for stations around Greenland Figure 1.1.4: Station positions and numbers for OSNAP East (part 1). Figure 1.1.5: Station positions and numbers for OSNAP East (part 2). Figure 1.1.6: Station positions and numbers for Extended Ellett Line. 1.2 Objectives Cruise JR302 was an NERC-NC funded cruise aiming to complete a full CTD section across the subpolar gyre, from Canada to Greenland to Scotland. The CTD section was located along the OSNAP track, providing a high quality and high-resolution synoptic survey for the start of that programme. The objectives included a full suite of biogeochemistry measurements under the RAGNARRoC programmes. Finally, the eastern part of the section included the 2014 occupation of the Extended Ellett Line between Scotland and Iceland. Additional sections were made around the Cape Farewell region with the objective of measuring transport and the movement of water away from the boundary currents. Additional objectives included deploying eight Met Office Argo floats, and recovering one SAMS glider. Two new instruments were trialed by deploying them on the CTD frame; the IMP and RBR. Figure 1.2.1: The scientific personnel of JR302 Team Physics Penny Holliday Damien Desbruyères Jonathan Lawrence Stefan Gary Felicity Williams Methane & Nitrous oxide Ian Brown Team Carbon Alex Griffiths Eithne Tynan Claudia Fry Jen Clarke Becky Gorley CTD Engineer John Wynar Principal Scientist Brian King Support Engineer Seth Thomas IT Engineer Andy England Team Nutrients/Oxygen Sinhue Torres-Valdes Hannah Donald Carolyn Graves Mark Stinchcome Team CFCs Marie-Jose Messias Peter Mead Gary Murphy Lilo Henke Tobia Tudino Surfactants & chlorophyll Bita Sabbaghzadeh 2. PROFILE MEASUREMENTS 2.1 CTD Sensors Seth Thomas SBE_Instrument Configuration SB_ConfigCTD_FileVersion="7.22.0.2" Name SBE 911plus Frequency Channels Suppressed 0 Voltage Words Suppressed 0 Computer Interface 0 !-- 1 == SBE11plus Firmware Version 5.0 --- Deck Unit Version 0 Scans To Average 1 Surface Par Voltage Added 0 Scan Time Added 0 Nmea Position DataAdded 1 Nmea Depth Data Added 0 Nmea Time Added 0 Nmea Device ConnectedToPC 1 Sensor index="0" Sensor ID="55" Temperature Sensor Sensor ID="55" Serial Number 03P-4472 Calibration Date 30 August 2012 G 4.41398102e-003 H 6.42799011e-004 I 2.19747460e-005 J 1.88664616e-006 F 1000.000 Slope 1.00000000 Offset 0.0000 Sensor index="1" SensorID="3" Conductivity Sensor SensorID="3" Serial Number 2875 Calibration Date 19 March 2013 G -1.01639718e+001 H 1.40355804e+000 I 8.86145233e-005 J 5.99096076e-005 CPcor -9.57000000e-008 CTcor 3.2500e-006 Sensor index="2" SensorID="45" Pressure Sensor SensorID="45" Serial Number 89973 Calibration Date 22 August 2012 C 1-4.925971e+004 C2 -2.136250e-001 C3 9.435710e-003 D1 3.900400e-002 D2 0.000000e+000 T1 2.983458e+001 T2 -3.883229e-004 T3 3.262440e-006 T4 3.429810e-009 Slope 1.00010000 Offset -1.27140 T5 0.000000e+000 AD590M 1.277500e-002 AD590B -9.391460e+000 Sensor index="3" SensorID="55" Temperature Sensor SensorID="55" Serial Number 03P-2366 Calibration Date 30 August 2012 G 4.31974772e-003 H 6.44172106e-004 I 2.35210024e-005 J 2.26433319e-006 F 01000.000 Slope 1.00000000 Offset 0.0000 Sensor index="4" SensorID="3" ConductivitySensor SensorID="3" SerialNumber 04C-2289 CalibrationDate 21 August 2012 G -1.04066323e+001 H 1.38729309e+000 I -2.46034773e-003 J 2.40168672e-004 CPcor -9.57000000e-008 CTcor 3.2500e-006 Slope 1.00000000 Offset 0.00000 Sensor index="5" SensorID="71" WET_LabsCStar SensorID="71" SerialNumber CST-846DR CalibrationDate 13 March 2013 M 21.6360 B -1.2938 PathLength 0.250 Sensor index="6" SensorID="5" FluoroChelseaAqua3Sensor SensorID="5" SerialNumber 088216 CalibrationDate 19 February 2013 VB 0.219400 V1 2.068800 Vacetone 0.228700 ScaleFactor 1.000000 Slope 1.000000 Offset 0.000000 Sensor index="7" SensorID="42" PAR_BiosphericalLicorChelseaSensor SensorID="42" SerialNumber 7235 CalibrationDate 24 April 2013 M 1.00000000 B 0.00000000 CalibrationConstant 33557046980.00000000 Multiplier 1.00000000 Offset -0.04219064 Sensor index="8" SensorID="0" AltimeterSensor SensorID="0" SerialNumber 244740 CalibrationDate 16 May 2012 ScaleFactor 15.000 Offset 0.000 Sensor index="9" SensorID="38" OxygenSensor SensorID="38" SerialNumber 0676 CalibrationDate 28-Aug-12 Soc 4.4589e-001 offset -0.4962 A -8.8979e-004 B 6.4609e-005 C -5.1722e-007 D0 2.5826e+000 D1 1.92634e-004 D2 -4.64803e-002 E 3.6000e-002 Tau 20 1.1700 H1 -3.3000e-002 H2 5.0000e+003 H3 1.4500e+003 2.2 CTD Data processing Brian King, Damien Desbruyeres, Penny Holliday CTD data processing followed the usual mexec path described in previous cruise reports, as follows. 2.2.1 Sea Bird Data processing • Preparation at the start of the cruise The first step is to select the SBE output variables. It is essential that the output variables include scan and pressure temperature. For example (JR302): # name 0 = timeS: Time, Elapsed [seconds] # name 1 = depSM: Depth [salt water, m] # name 2 = prDM: Pressure, Digiquartz [db] # name 3 = t090C: Temperature [ITS-90, deg C] # name 4 = t190C: Temperature, 2 [ITS-90, deg C] # name 5 = c0mS/cm: Conductivity [mS/cm] # name 6 = c1mS/cm: Conductivity, 2 [mS/cm] # name 7 = sal00: Salinity, Practical [PSU] # name 8 = sal11: Salinity, Practical, 2 [PSU] # name 9 = sbeox0V: Oxygen raw, SBE 43 [V] # name 10 = sbeox0Mm/Kg: Oxygen, SBE 43 [umol/Kg] # name 11 = sbeox0ML/L: Oxygen, SBE 43 [ml/l] # name 12 = xmiss: Beam Transmission, Chelsea/Seatech/WET Labs CStar[%] # name 13 = flC: Fluorescence, Chelsea Aqua 3 Chl Con [ug/l] # name 14 = turbWETbb0: Turbidity, WET Labs ECO BB [m^-1/sr] # name 15 = altM: Altimeter [m] # name 16 = scan: Scan Count # name 17 = ptempC: Pressure Temperature [deg C] # name 18 = pumps: Pump Status # name 19 = latitude: Latitude [deg] # name 20 = longitude: Longitude [deg] # name 21 = flag: 0.000e+00 - Oxygen hysteresis correction: decide whether to use the SBE oxygen hysteresis correction using standard parameters, or whether to derive your own. Look at options in the SBE data conversion program: it is here that the hysteresis correction is applied and you can uncheck that option. Make sure that mstar script moxy_02b is edited to match your requirement. • SBE Data Processing On the CTD logging computer, the SBE Data Processing software was used for initial processing when the cast was finished, by running the following: Data Conversion to convert the raw frequency and voltage data to engineering units as appropriate by applying the manufacturer's calibrations stored in the CON file and save both downcast and upcast to an ASCII format file. Can include hysteresis correction using SBE parameters. Align CTD to align the oxygen sensor in time relative to pressure. Cell Thermal Mass to correct the pressure and conductivity. Output File: JC86_NNN_actm.cnv 2.2.2 MSTAR Data Processing • Preparation at the start of the cruise - Data are retrieved from the ship's data directories by the use of symbolic links in ctd_linkscript - Edit ctd_linkscript to pick up the files using the symbolic links, check format of lines that extract information from SBE filenames to create the standard mstar names. The script only picks up data files not already copied to the ASCII_FILE directory. Edit the list of variable names that you require for your sample file. This will vary from cruise to cruise depending on which samples are being collected. The list of variables is contained in the file /data/templates/sam_jr302_varlist.csv. - Create a template csv file in which you will input information about bottle firing, ready for pasting into the master sample file later. It is useful to create a blank master file with all bottles set to flag 2 (No problems noted), to be edited after each cast when bottles are either not fired (flag 9), or don't trip correctly (flag 4) etc. File: /data/ctd/ASCII_FILES/bot_jr302_001.csv. • ctd_linkscript was used to copy the data from the ship's network drive to the NOCS Sun workstation FOLA. The files are copied with their original names, then a symbolic link created for each one with the name in the format expected by standard mstar scripts. • MatLab was opened and 'm_setup' run to setup the environment for mexec processing. The MSTAR processing was split into several phases. 'ctd_all_part1' included the following: • msam_01 creates an empty sam file sam_jr302_NNN.nc (make sure that the list of variable contains the expected channels); • mctd_01 reads in 24Hz CTD data into ctd_jr302_NNN_raw.nc; • mctd_02a renames SeaBird variable names in ctd_jr302_NNN_raw.nc ; • mctd_02b carries out oxygen hysteresis correction using SBE default parameters or users preferred parameters (edit as appropriate, check it matches your decision for SEBE data processing). Creates ctd_jr302_NNN_24hz; • mctd_03 averages data to 1Hz (output to ctd_jr302_NNN_1hz.nc) and calculates derived variables (output to ctd_jr302_NNN_psal.nc); • mdcs_01 creates empty dcs file which will store information about start, bottom and end of good data in CTD file; • mdcs_02 populates dcs file with data to identify bottom of cast. • mdcs_03g allows the user to decide which scan numbers mark the start of the downcast and the end of the upcast. This is a graphical interface. The start of the downcast was selected to be the lowest pressure after the CTD had soaked and been brought to the surface before descending. The end of the downcast was selected as the last scan for which there was good in-water oxygen, temperature, conductivity and salinity data (note that oxygen data becomes out-of-water before the other variables because the different sensor response times). Output to dcs_jr302_nnn.nc. Phase 3 routines grouped under 'ctd_all_part2' ran the following: • mctd_04 extract downcast data from psal file using index information from dcs file; sort, interpolate gaps and average to 2db (output to ctd_jr302_NNN_2db.nc); • mdcs_04 merge positions of start, bottom and end cast from navigation file into dcs file; • mfir_01 read in information from SeaBird .bl file and create netCDF fir file; • mfir_02 merge time from ctd file onto fir file using scan number (output to fir_jr302_NNN_time.nc); • mfir_03 merge CTD upcast data onto fir file; • mfir_04 paste CTD fir data into sam file and output to sam_jr302_NNN.nc; • mwin_01 creates win file which will hold winch data and extracts times from start and end of 1Hz ctd file; • mwin_03 merge winch wire out data onto fir file; • mwin_04 paste winch fir data into sam file; At this point the data can be examined using some scripts to generate standard plots: • mctd_checkplots and mctd_rawshow generate a series of plots of raw, 1hz and 2db data. mctd_checkplots allows a series of previous casts to be plotted also. The plots should be examined for data quality. • mctd_rawedit is a graphical interface that allows the user to manually select bad data cycles in temp, cond and oxygen. Preserves original raw file as ctd_jr302_nnn_raw_original.nc and outputs new file ctd_jr302_nnn_raw_cleaned.nc. The cleaned file is linked by a new symbolic link called ctd_jr302_nnn_raw.nc so that following scripts work on the cleaned version if it exists. The editing is done on the raw data file so that edits are preserved throughout all derived files. So after the edits are finished, the derived files need to be re-generated. This is done in steps mctd_02b, mctd_03, mctd_04, mfir_03, mfir_04. These scripts can be run manually or using smallscript.m (check and edit this first). • list_ctd_1hz(nnn) generates and ascii listing of the 1hz file ready for use in the LADCP processing. Each file was saved in /data/ctd and a symbolic link created to it from the LADCP directory (/data/ladcp/ix/data/CTD/) • mbot_01.m takes bottle firing quality flags manually set in bot_jr302_001.csv. Output: bot_jr302_nnn.nc. • mbot_02.m pastes the bottle firing codes into sam jr302_nnn.nc As header information for the CTD data files becomes available, the information in the files can be updated through the following steps: • mdep_01.m requires a matlab file (station_depth_jr302.mat) containing water depth in variable 'bestdeps'. On JR302 this information came from the LADCP data files where it existed, or from the bathymetry file (saved as ascii file ctd_depths.csv). Where there was neither LADCP or bathymetry data (one station) the depth was left as NaN. mdep_01.m pastes this information into headers of all CTD files. • mdcs_04.m takes the lat and lon from the navigation (pos_jr302_01) at the time of start, bottom and end of each cast and pastes into dcs_jr302_nnn_pos.nc. • mdcs_05.m pastes the lat and lon for the bottom of the cast into the headers of all CTD files. 2.3 CTD calibrations Penny Holliday, Brian King, Damien Desbruyères 2.3.1 Oxygen When oxygen bottle data had been pasted into the CTD sample files, and the individual station sample files had been appended (sam_jr302_all), the data were used to examine the performance of the CTD oxygen sensor. First the relationship between the bottle oxygen and uncalibrated CTD oxygen was derived (bottle sample units were converted to umol/kg using the calibrated CTD salinity). The standard procedure is to define an initial correction to the data (linear or quadratic), then apply further temperature- and/or pressure- dependent corrections if the calibrated residuals suggest one is required. For JR302 data, a linear initial fit followed by a pressure correction was applied. The fit was used to define coefficients as follows: CTD_oxycal = a*CTD_oxygen + b where a = 1.0633 and b = 16.91. The subsequent pressure correction applied was a linear offset defined by interpolations between offset- pressure pairs (-1, 0), (0, 1000) and (4, 3800). These coefficients are specified in function oxy_apply_cal.m called by mctd_oxycal.m In mstar: • mctd_oxycal: used to apply these calibrations to the CTD files (ctd_jr302_nnn_24hz). After calibrations have been applied, subsequent steps need to be repeated (mctd_03, mctd_04, mfir_03, mfir_04) this was done by editing and running smallscript.m. All sam_jr302_nnn files were re-appended to create a new version of sam_jr302_all.nc that contained the calibrated CTD conductivity, salinity and oxygen. The calibration was initially determined from the first 30 stations of the cruise and subsequently monitored against newer samples. The CTD oxygen sensor was remarkably stable and this calibration was used unchanged for the rest of the cruise. Variations in the oxygen bottle residuals were associated with new batches of reagents used in the titrations up to station 179. The offsets between batches of chemicals was order 2 umol/kg and this can be considered to be the level of uncertainty associated with the samples. From station 180 onwards however, there is an issue with the bottle oxygen samples that led us to label them all as "suspect data" (coloured red in Fig. 2.3.1). Those samples were not used to correct the CTD sensor. Examination of the CTD temperature-oxygen relationship before and after station 180 has led us to conclude there was no observable drift in the sensor to the end of the cruise. The mean of the oxygen residuals (good samples from stations 1-180, and excluding outliers) was -1.1 ± 2.5 umol/kg. Figure 2.3.1: Distribution of bottles fired (cyan) and "good" oxygen samples (black). Samples from stations 180 onwards are shown as red. Figure 2.3.2: Calibrated CTD oxygen against bottle oxygen. Samples from stations 180 onwards are shown as red. Figure 2.3.3: Calibrated oxygen residuals against station number. Samples from stations 180 onwards are shown as red. Figure 2.3.4: Calibrated oxygen residuals against pressure. Samples from stations 180 onwards are shown as red. 2.3.2 Salinity Calibration CTD conductivity was calibrated with the water sample bottles (see section 3.1). 2.4 LADCP 2.4.1 Instrument technical details A downward looking 300 kHz Workshorse LADCP was attached to the CTD frame for JR302. The configuration was 16x10m bins with data collected in beam co-ordinates and rotated to earth co-ordinates during processing. The LADCP was connected to a charger and by a serial cable to a BAS AME- supplied laptop in the Chem Lab for programming and testing prior to each data, and data download after each station, using BB-talk. Data downloaded after each station were copied to the network legdata drive, along with the pre-deployment logs. Command file: CR1 RN J302M WM15 TC2 LP1 TB 00:00:02.80 TP 00:00.00 TE 00:00:01.30 LN25 LS0800 LF0 LW1 LV400 SM1 SA011 SB0 SW5500 SI0 EZ0011101 EX00100 CF11101 CK CS 2.4.2 Data Processing Data from each station were processed on workstation FOLA using two software packages; the University of Hawaii software, and the Lamont- Doherty IX software. 2.4.3 IMP John Wynar The IMP mk 3 consists of a Raspberry Pi (RPi) micro computer, and separate clock and 3-axis tilt/magnetic field sensor boards. Communication with the device is achieved wirelessly. Initially, when these boards were connected together and 5V power applied from a Farnell PSU, communication could not be established. However, subsequent testing using a proprietary PSU was successful and the system functions validated. The boards were then assembled together with a dc/dc converter which would provide the 5V necessary to power the system, stepped down from the 50V (approximately) of the LADCP battery pack. With the long antenna fitted, wireless communication with the IMP was easily achieved even when fitted into its pressure case and on the CTD frame. The pressure case was tested on the CTD frame to a depth of over 3000m without the IMP inside to ensure its water tight integrity. Calibration of the IMP inside the pressure case was carried out in the lab as per the instructions and the data logged. As the IMP sensor board was to be kept to near horizontal when fitted, a line was drawn on the end cap to show the orientation of the boards when in the pressure case. In actual operation, communication with the IMP was carried out using a laptop in the laboratory adjoining the CTD annexe. Logging (and other house-keeping tasks) was initiated and terminated using the Tera Term terminal software. Data were copied and backed up onto a network drive using WinSCP. Start and stop times were written onto a log sheet and referenced to the station number. Problems only occurred on two occasions, the first after some 26 days of operation, when communication with the IMP could not be established. On the first occasion, power cycling the unit was attempted but without success. The next step was to remove the IMP from its pressure case and investigate further. Bench testing did not reveal any fault so the system was re-assembled and fitted back into the CTD frame and operation continued. The system “hung up” again two days later. This time simple power cycling re-booted the IMP and communication re-established. It is possible that insufficient time was given on the first occasion between disconnecting and re-applying power for a re-boot to take effect. The data collected from the IMP during the cruise will be sent to the designer, Andreas Thurnherr, for analysis. 2.5 RBR Concerto CTD John Wynar The instrument (S/N 065583) was attached to brackets fitted to a vertical stanchion on the CTD frame (constructed of stainless steel) with the plastic clamps provided (Figure 2.5.1). This gave a separation of about 50mm between the conductivity cell and the metalwork of the frame. This position was the best compromise which could be attained considering the aspects of (i) accessibility (to switch on logging), (ii) safety (to prevent accidental damage), (iii) free uncontaminated current flow through the cell, and (iv) proximity to the frame (affecting the cell’s external field). The unit was depth rated for 2000 m, hence it was necessary to remove the instrument for CTD casts in excess of this. For the sake of convenience, it was also removed prior to the final shallow casts near to the Scottish coast. In any case, by then the instrument had logged over a hundred “dives” which was deemed sufficient for the purpose intended. The instrument’s logging could be initiated without using a computer which made it very simple to use. The end cap was simply twisted to a point where two marks lined up, the starting of logging confirmed by a slight and short period of vibration coming from inside the unit. To disable logging, the end cap was twisted to come in line with a different mark, again confirmed by a period of vibration. The instrument was downloaded several times using the Ruskin software when it was convenient to do so, for instance when it had to be removed for deeper stations. On the first occasion, logging was disabled (for no particular reason). However, it was unknown at that point that when logging was re-enabled this would mean that the memory would be erased. It might be beneficial in a future revision of the software to allow logging to be enabled without erasing the memory. Also on this occasion, the clock was corrected to GPS time (albeit it was only 1 second slow) and the battery voltage recorded as 11.81V as displayed in the Ruskin software. On successive occasions, the battery voltage was noted as not being less than 12.0V, the fifth and final value being 12.02V. (The author also suggests that a channel displaying the battery voltage during deployment would be useful.) After re-setting the onboard clock during the first download, the clock was found to be 5 seconds slow some 29 days later. Total memory used at this point was 45.14MB although there was no numerical display of the memory remaining. There was, however, a sliding bar giving a graphical representation of unused memory. Figure 2.5.1: The RBR concerto CTD attached to the stainless steel frame. 3. WATER SAMPLE MEASUREMENTS 3.1 Salinity Team: Brian King, Penny Holliday, Stefan Gary, Damien Desbruyères, Jonathan Lawrence, Felicity Williams, John Wynar Water samples from CTD casts and TSG underway measurements were analysed with a salinometer to retrieve accurate estimates of the conductivity ratio for further calibration of the CTD/TSG data. Crates of water samples and sea water standards (batch P156; K15 = 0.99984) were stored at the same temperature for at least 24 hours in the laboratory room before being analysed following the usual procedure of 3 rinsing – 3 reading – average for each sample and standards. One (sometimes two) standard seawater (SSW) samples were run before and after each crate of samples. All readings were numerically recorded and saved in Excel and csv files as “sal_jr302_stationnumber” before being merged together in “sal_jr302_01.csv”. The lab temperature fluctuated between about 20 and 23.5 °C. The same salinometer was used for most of the analysis (serial number 68959) and showed a satisfactory behaviour (light cycling, constant temperature, stability) during the whole cruise. A drift (probably electronically- related) in the standard conductivity ratio was however revealed from standard 25 to standard 100 (see Figure 3.1.1). This initiated the use of a secondary machine (serial number 63360), which was yet aborted after noticing an inconsistency between the machine reading and the software display (station 66/67). The drift disappeared at about station 100 and standard conductivity ratio stabilized around 1.99980, although some “short-term” spreading around this value continued to be observed (e.g. higher ratios for standards 170 to 180, lower ratios for standards 230 to 239). Figure 3.1.1: The difference between the salinometer-measured conduc- tivity ratio and the label ratio of SSW samples (x10-5). Figure 3.1.2: The offsets applied to all bottle conductivity ratios (derived from Figure 3.1.1, see also Table 3.1.1) (black) and the residuals after corrections applied. By visually inspecting the temporal behaviour of the standard conductivity ratios, a correction was applied to sets of station samples. These offsets are given in the table below. The resulting calibrated bottle salinities were then used to adjust the CTD data. Table 3.1.1: Offset applied to conductivity ratio, derived from SSW analysis Station number Offset applied to conductivity ratio (*10-5) —————————————— ———————————————————————————————————————————— 1 to 20 0 21 to 30 -1 31 to 32 -2 33 to 36 -3 37 to 40 -4 41 to 46 -5 47 to 54 -6 55 to 60 -7 61 to 63 -8 64 to 65 -9 66 to 67 0 67 to 74 -9 75 to 79 -10 80 to 90 -11 3.2 Dissolved Oxygen Team: Hannah Donald, Carolyn Graves, Mark Stinchcombe and Sinhue Torres-Valdes All stations (except where no bottles were fired and one occasion when the night shift carried out a safety drill) occupied during JR302 were sampled for dissolved oxygen (DO). Sampling for DO was done just after CFCs and surfactants were sampled, or first when CFCs and surfactants were not sampled. Seawater was collected directly into pre-calibrated glass flasks using a Tygon® tube. Before the sample was drawn, bottles were flushed with seawater for several seconds (for about 3 times the volume of the bottle) and the temperature of the water was recorded simultaneously using a hand-held thermometer. The fixing reagents (manganese chloride and sodium hydroxide/sodium iodide solutions) were then added. Care was taken to avoid bubbles inside the sampling tube and sampling bottle, and a water seal was used after the sample was fixed and stoppered. Samples were thoroughly mixed following the addition of the fixing reagents and were then kept in a dark plastic crate for 30-40 min to allow the precipitate to settle to <50% the volume of the bottle. Once the precipitate had settled all samples were thoroughly mixed for a second time in order to maximize the efficiency of the reaction. Analyses were carried out within 2-4 h of sample collection. Methods DO determinations were made following the Winkler method using a potentiometric Ω-Metrohm titration unit (916 Ti-Touch, with electronic burettes). Chemical reagents were previously prepared at NOCS following the procedures described by Dickson (1994). Recommendations given by Dickson (1994) and by Holley and Hydes (1994) were adopted. Oxygen calibration Titrations were carried out with a thiosulphate solution which was prepared at least 24 hours before use (50 g dissolved in 1 L of Milli-Q water). Its concentration was determined by the use of certified OSIL standards of known molarity (1.667 mmol L-1). Typically, calibrations were carried out every 3-4 days to monitor potential changes in the concentration of the thiosulphate. Calculation of oxygen concentrations were facilitated by the use of an Excel spreadsheet set up with unique flask calibrated volumes and reagent dispenser volumes. When a new calibration was done, calculation sheets were updated with the latest numbers and oxygen concentrations determined with those results until a new calibration was completed. By examining the results of the calibrations carried out for a given batch of thiosulphate we determined that there was no significant drift in the concentration, and that the slight differences in the calibration results are likely due to instrument sensitivity and analytical noise. Hence, it was decided that an average of the calibrations done for a specific batch of thiosulphate was the best option to produce consistent results for oxygen concentration in samples as determined by plotting the difference between oxygen measurements against the CTD sensor data (residuals). Table 3.2.1 lists the calibrations carried out during JR302 separated by thiosulphate batch, showing the results of the blank and standard, as well as the averages for a given thiosulphate batch. For every cast replicates were taken from randomly selected Niskin bottles to assess reproducibility of the analysis. Figure 3.2.1 shows the results of replicates (same Niskin bottle sampled twice) selected randomly in every cast. Overall (except values flagged as bad), reproducibility was between 0.3 and 1 umol L-1. Problems encountered From CTD cast 180-200, a drift was noted in the residuals. Examination of CTD data suggested that the oxygen sensor was not responsible for this drift, and given that no chemical reagents or thiosulphate solution were changed during these measurements, we believe that the titration probe may be responsible for this drift for reasons we do not understand; all of a sudden the amount of thiosulphate added to titrate a sample at a specific depth increased relative to neighbouring stations at similar depths. The addition of thiosulphate was determined potentiometrically by the probe, and just as the problem appeared, it also disappeared. By the time this report was completed, this issue remained unresolved. Figure 3.2.1: The absolute replicate difference for the oxygen bottles in each CTD cast (n=236). The mean (0.96 mmol L-1) and the standard deviation of –all values in the plot considered- are specified with solid and dash line respectively (± 1.4 mmol L-1). Green symbols show replicate values flagged as good (0 - 0.3 mmol L-1), yellow symbols show replicate values flagged as good (0.3 - 1.1 mmol L-1) and red symbols show remaining data, including values flagged as dubious or bad (1.1 mmol L-1 and above). References Dickson, A.G. (1994) Determination of dissolved oxygen in seawater by Winkler titration. Technical report, WOCE operations manual, WOCE report 68/91 Revision 1 November 1994. Holley, S.E. and Hydes, D.J. (1994) Procedures for the determination of dissolved oxygen in seawater. Technical report, James Rennell Centre for Ocean Circulation. Table 3.2.1: JR302 Dissolved O2 analysis calibrations; showing number of casts analysed with a given thiosulphate batch, dates on which calibrations were carried out, stations for which concentrations were originally calculated with a given calibration, mean blank titre volume (BLK) per calibration and per thiosulphate batch, standard titre volume (STD) per calibration and per thiosulphate batch, STD minus BLK, molarity of thiosulphate per calibration and per thiosulphate batch, standard deviation (stdev) of average molarity and stdev as percent of the mean molarity. No. Date Station Blank Blank Standard Standard STD- Molarity Average Stdev % Casts No. AVERAGE AVERAGE BLK —————— —————————— —————————— ——————— ——————— ———————— ———————— —————— ———————— ——————— ———————— ————— 04/06/2014 training 0.01190 0.51920 0.5073 0.199 07/06/2014 CTD001-003 0.01326 0.51520 0.5019 0.2010 001 10/06/2014 CTD004-026 0.01335 0.51622 0.5029 0.2006 42 - 14/06/2014 CTD027-37 0.01320 0.51763 0.5044 0.2000 042 16/06/2014 0.01310 0.51532 0.5022 0.2008 16/06/2014 CTD040-42 0.01274 0.01311 0.51410 0.51521 0.5014 0.2012 0.2007 0.000468 0.23 043- 17/06/2014 CTD043-62 0.01476 0.51210 0.4973 0.2028 33 076 21/06/2014 CTD063-76 0.01328 0.01402 0.51268 0.51239 0.4994 0.2020 0.2024 0.000593 0.29 077 24/06/2014 CTD077-96 0.01358 0.51524 0.5017 0.2011 37 - 27/06/2014 CTD097-111 0.01364 0.51870 0.5051 0.1997 115 30/06/2014 CTD112-115 0.01336 0.01353 0.51746 0.51713 0.5041 0.2001 0.2003 0.00070 0.35 116 01/07/2014 CTD116-130 0.01392 0.51700 0.5031 0.2005 62 - 04/07/2014 CTD132-177 0.01396 0.51570 0.5017 0.2010 177 10/07/2014 0.01296 0.01361 0.51626 0.51632 0.5033 0.2004 0.2006 0.000337 0.17 180- 10/07/2014 CTD180-205 0.01438 0.51460 0.5002 0.2016 54 234 15/07/2014 CTD206-234 0.01330 0.01384 0.51516 0.51488 0.5019 0.2010 0.2013 0.000467 0.23 3.3 Total Dissolved and Dissolved Inorganic Nutrients Team: Hannah Donald, Carolyn Graves, Mark Stinchcombe and Sinhue Torres-Valdes Lab Set up A 7-channel Seal Analytical AA3 autoanalyser was set up in the main lab of the JCR for the analysis of micro-molar concentrations of dissolved inorganic nutrients (silicate, phosphate, nitrate plus nitrite-hereafter nitrate-, nitrite and ammonium) and total nutrients (total dissolved phosphorus and total dissolved nitrogen). Two members of the team (CG and ST) arrived on the ship on the 28th May to start mobilisation. Flight cases with instrumentation were distributed within the lab and chemical reagents identified and stored in the respective ship’s hazardous chemicals lockers. The two other members (HD and MS) arrived on the 30th when instrument installation began. Installation of the AA3 took two full days, involving; the fitting of new pump tubing and new cadmium columns, tubing connections between sampler-pumps-manifold-detectors, and a thorough cleaning with wash solutions as per Seal Analytical protocols. Simultaneously, chemical reagents (stock and working solutions) and standards (stock solutions and calibrants) were prepared. ‘Stocks’ are concentrated solutions from which working reagents/standards are prepared as required by solution stability or usage. Working standards were prepared in a saline solution (40 g NaCl in 1 L of Milli-Q water, here after artificial seawater or ASW), which was also used as a diluent for the analysis. Seal Analytical protocols used during JR302 were: i. Silicate in seawater method No. G-177-96 Rev 10 (Multitest MT19). ii. Phosphate in water and seawater method No. G-175-96 Rev. 13 (Multitest MT 18). iii. Total dissolves phosphorus in seawater method No. MKA-0152-14 Rev. 0. iv. Total dissolved nitrogen in seawater method No. G-218-98 Rev. 12 (Multitest MT23). v. Nitrate and nitrite in seawater method No. G-172-96 Rev. 13 (Multitest MT19). vi. Nitrite in seawater method No. G-062-92 Rev. 3. vii. Ammonium in water and seawater No. G-327-05 Rev. 6. Calibrants Table 3.3.1 lists compounds used for the preparation of stock standard solutions, weight of compound dissolved in 1 L of Milli-Q water and the resulting molarity of the solution. Dilutions were then made from stock solutions to prepare a set of five standards to calibrate the analysis. Table 3.3.2 shows target concentrations -which are concentrations aimed for when preparing the standards- and actual concentrations –which have been obtained given the molarity of stock solutions and/or that result from the combination of related chemical species (e.g., TN, NO3-+NO2-, NO2-, NH4+). Table 3.3.1: Compounds used to prepare stock standard solutions, weight dissolved in 1 L of Milli-Q water and Molarity of the solution. Compound Weight (g) Molarity 1 L stock solution ——————————————————————————————— —————————— ——————————————————————————— Ammonium Sulphate 0.6919 10.0118 Potassium Nitrate 0.5066 5.0107 Sodium Nitrite 0.3449 4.9989 Potassium Di-hydrogen Phosphate 0.6811 5.0049 Sodium Metasilicate 1.4219 5.0032 Table 3.3.2: Set of calibration standards (Std) used for dissolved inorganic and total dissolved nutrient analysis. Concentration units are mmol L-1. Target concentrations are shown in bold characters. Actual concentrations as calculated from the molarity of the stock solution are shown in normal characters. Note that concentrations for NO3-+NO2- are the sum of NO3-+NO2- and NO2-, and concentrations for TN also include those of NH4+. Si(OH)4 PO43-/TP TN NO3-+NO2- NO2- NH4+ ————— ————————— —————————— ————————— ————————— ————————— ————————— Std 1 1 1.00 0.25 0.25 1 1.20 1 1.10 0.1 0.10 0.1 0.10 Std 2 5 5.00 0.75 0.75 5 6.51 5 5.51 0.5 0.50 1.0 1.00 Std 3 10 10.01 1.50 1.50 10 13.02 10 11.02 1.0 1.00 2.0 2.00 Std 4 20 20.01 3.00 3.00 20 25.54 20 22.04 2.0 2.00 3.5 3.50 Std 5 30 30.02 5.00 5.00 30 38.07 30 33.06 3.0 3.00 5.0 5.00 Although the range of calibrant concentrations is typically determined by minimum and maximum expected nutrient levels at any given location, for JR302 the range of calibrants for phosphate and ammonium were set to 5 mmol L-1 despite the fact that maximum concentrations in the area of investigation were not expected to be greater than 1.5 mmol L-1 and ~2 mmol L-1 for phosphate and ammonium, respectively. In the case of phosphate the decision was taken following lab based tests of the TP channel (which uses the same calibrants as those for phosphate) and whose performance was not acceptable at calibration levels of ≤2.5 mmol L-1. Once on board JR302, a top standard level of 5 mmol L-1 was found to properly reproduce peak shapes. In the case of ammonium, lab tests showed ammonium peak shapes were also not acceptable at ≤2.0 mmol L-1. Poor peak shape is observed at low concentrations because the resulting amplified instrument gain also amplifies the noise signal, rendering analytical results unreliable. Unfortunately, less than two weeks into the cruise the TP channel stopped working. Attempts were made to fix it, but the work load did not allow for much time to be spent on this and it was then decided that samples from selected stations (upper 150 m of the water column where DOP occurs at detectable levels) would be collected and stored frozen for later analysis on land. At the same time, the ammonium channel was found to be performing well and reliably. Thus, from run 19 the calibrant range for phosphate and ammonium was changed as shown in Table 3.3.3. Additionally, the silicate range was increased to include the certified values (KANSO CRMs) for this variable, which were slightly higher than our original adopted range. Table 3.3.3: Set of calibration standards (Std) used for dissolved inorganic and total dissolved nutrient analysis from run 19 (see text for further information). Concentrations in µmol L-1. Si(OH)4 PO43-/TP TN NO3-+NO2- NO2- NH4+ ————— ————————— —————————— ————————— ————————— ————————— ————————— Std 1 1 1.00 0.10 0.25 1 1.20 1 1.10 0.1 0.10 0.1 0.10 Std 2 5 5.00 0.50 0.75 5 6.01 5 5.51 0.5 0.50 0.5 0.50 Std 3 10 10.01 1.00 1.50 10 12.02 10 11.02 1.0 1.00 1.0 1.00 Std 4 20 20.01 2.00 3.00 20 24.05 20 22.04 2.0 2.00 2.0 2.00 Std 5 40 40.03 3.00 5.00 30 36.07 30 33.06 3.0 3.00 3.0 3.01 Quality Controls (QCs) Organic standards: Total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP) are measured as nitrate and phosphate respectively following oxidation of the sample by exposure to UV radiation and a wet chemical oxidation with potassium persulphate. During JR302 five organic compounds containing phosphorus and/or nitrogen were used to test the efficiency of the oxidation. Table 3.3.4 lists the compounds used to prepare stock solutions and Table 3.3.5 lists the concentration of standards prepared, the average concentration measured during the cruise for each compound, the standard deviation of all measurements, and the percent oxidation efficiency. Time series of the recovery of nitrogen from each of the organic compounds used are shown in Figure 3.3.1. Table 3.3.4: Compounds used to prepare stock organic standard solutions to test oxidation efficiency of TDN and TDP, weight dis- solved in 1 L of Milli-Q water and Molarity of the solution. Compound Weight (g) N molarity 1 L stock solution ————————————————————————————— —————————— ————————————————————————————— Caffeine (Caff) 0.1203 2.4780 Urea (Ur) 0.1547 5.0509 Adenosine triphosphate (ATP) 0.3030 2.5033 Guanosine monophosphate (GMP) 0.2065 2.5106 Adenosine monophosphate (AMP) 0.1895 2.5685 Table 3.3.5: Set of organic standards used to test the oxidation efficiency of the TDP and TDN channels. This table shows prepared concentration ([ ]), average concentration ([Av]) of total measurements (n) during JR302 and respective standard deviation of measurements, and average percent (%) oxidation efficiency. Concentration units are mmol L-1. | N | P —————|————————————————————————————|—————————————————————————— | [ ] [Av] Sd n % | [ ] [Av] sd N % Caff | 4.99 4.24 0.18 54 85.4 | ---- Ur | 5.05 4.09 0.91 54 81.0 | ---- ATP | 2.50 1.77 0.20 54 70.6 | 1.50 0.81 0.02 3 54.1 GMP | 5.02 3.03 0.22 54 60.4 | 1.00 0.73 0.01 3 73.0 AMP | 5.14 3.84 0.14 53 74.7 | 1.03 0.97 0.04 3 93.7 Certified Reference Materials (CRM) from Hansell’s Lab (University of Florida, USA) from deep and surface Atlantic Ocean waters were also used to test the oxidation efficiency for TN. These CRMs are designed for the measurement of dissolved organic carbon and dissolved organic nitrogen via high temperature combustion and are fixed with small amounts of hydrochloric acid. In order to measure them with the colorimetric techniques employed here, we needed to neutralise their pH of ~3.00 to a pH of 7.0 using NaOH (20-50 mL of a 10.2 M solution). Although this introduced noise to these measurements, these CRMs provided an additional test for the oxidation efficiency of the method (not shown here). Figure 3.3.1a: Time series of the nitrogen recovered (TN autoanalyser channel) from the various organic compounds used to test the oxidation efficiency of the method (concentration plotted against run number; n=54). Error bars show the standard deviation of the global mean. The concentration of nitrogen of each organic compound was 5 mmol L-1, except ATP, which was 2.5 mmol L-1. Figure 3.3.1b: Time series of the nitrogen recovered (TN autoanalyser channel) from the various organic compounds used to test the oxidation efficiency of the method (concentration plotted against run number; n=54). Error bars show the standard deviation of the global mean. The concentration of nitrogen of each organic compound was 5 mmol L-1, except ATP, which was 2.5 mmol L-1. Inorganic nutrients: In order to test the accuracy and precision of the analyses, CRMs from The General Environmental Technos Co., Ltd., (KANSO) were measured in all but one run. During JR302 KANSO CRMs lot CA and lot BU were used; certified concentrations of both are shown in Table 3.3.6. Lot CA is water from Suruga Bay, Japan, collected at 270 m depth, 19ºN, 130ºE, salinity 34.376 (certified date 19/06/2013, production date 22/02/2013, expiry date 22/02/2019). Lot BU is from the Suruga Bay, Japan, collected at 397 m depth, 32ºN, 144ºE, salinity 34.538 (certified date 03/08/2012, production date 26/04/2011, expiry date 26/04/2017). Average results from the measurement of KANSO CRMs are also shown in Table 5. The methods employed here are able to reproduce the CRMs values for nitrate+nitrite and phosphate within the overall analytical uncertainty. However, our methods seem to underestimate nitrite and silicate by 0.017 mmol L-1 (Lot CA) and 0.016 mmol L-1 (Lot BU) and by 3.99 mmol L-1 (Lot CA) 2.69 mmol L-1 (Lot BU) for nitrite and silicate, respectively (see Table 5). Although no certified concentration is reported for TN, measurements of KANSO CRMs provided consistent values throughout the cruise (Lot CA 21.68±1.19 mmol L-1; Lot BU 8.03±0.64 mmol L-1). Table 3.3.6: Certified concentrations (mmol kg-1) of KANSO CRMs used dur- ing JR302 and our results for each lot (also in mmol kg-1). | Nitrate Nitrite Silicate Phosphate ————————————|—————————————— —————————————— ———————————— ————————————— KANSO CA | 19.56 ± 0.19 0.055 ± 0.0047 36.06 ± 0.30 1.419 ± 0.029 KANSO BU | 3.88 ± 0.063 0.068 ± 0.0043 21.01 ± 0.68 0.372 ± 0.010 ————————————|—————————————— —————————————— ———————————— ————————————— Measured CA | 19.48 ± 054 0.038 ± 0.019 32.07 ± 0.45 1.47 ± 0.03 Measured BU | 3.94 ± 0.21 0.052 ± 0.021 18.32 ± 0.62 0.36 ± 0.01 Cadmium column reduction efficiency: The reduction of the nitrate (NO3-) present in a sample or from the oxidation of TN in a sample, to nitrite (NO2-), is achieved by passing the sample through a column filled with granular cadmium (cadmium column); cadmium is oxidised and nitrate is reduced. With use, the capacity of the cadmium column to reduce nitrate diminishes. The reduction efficiency was determined in every run by measuring nitrite and nitrate standards of similar concentrations (30 mmol L-1). The ratio of nitrate to nitrite expressed as a percentage provides an indication of the reduction efficiency of the cadmium column. For the analysis to produce reliable results, the oxidation efficiency needs to be >90%. When the efficiency is lower, the cadmium column is typically replaced. New cadmium columns are conditioned by flushing ammonium chloride through them for at least 10 hours; the time it takes to attain stable reduction efficiencies. AA3 Test Upon installation, the AA3 was tested by carrying out three analytical runs. For the first test, only standards (calibrants) were used to provide an indication of the linearity of calibration curves. This was followed by two runs with a full set of QCs standards and KANSO and Hansell’s Lab CRMs to verify the system was working properly. Following the tests, every run was set up as shown in Table 3.3.7. Analyses Seawater was collected for the analysis of micro-molar concentrations of dissolved inorganic and total nutrients. Samples were collected directly into 15 mL plastic centrifuge tubes. These were rinsed with sample water at least three times before withdrawing the sample. Tubes were stored in a fridge at approximately 4°C until sampling for 2 or more stations was completed; analyses were thus carried out for typically 2-10 stations at a time depending on frequency of sampling and number of samples per cast. Analyses of individual CTD casts were thus done from just after sampling to within 10 h after sample collection. All unique sampling depths were sampled and analysed. Observations Prior to the cruise all labware was washed with 10% HCl and rinsed with MQ water. Once on board, all labware was rinsed several times before use. Following each run, each analytical channel was flushed with wash solutions and the autosampler with Milli-Q water following Seal Analytical cleaning protocols. At least once per week the system was thoroughly cleaned with sodium hydroxide (TP lines), ~10 % hydrochloric acid (ammonium), and sodium hypochlorite (nitrite, nitrate, TN, phosphate and silicate line). After turning the AA3 on, about 2 hours are required before obtain stable baselines are established and a run can be started (approximately 30 minutes of flushing the instrument with wash solutions (as per Seal Analytical protocols) and 1.5 h flushing channels with their respective chemical reagents). Batches of ASW were prepared about twice per week, and the different chemical reagents were prepared from daily, to every 2 or 3 days. Samples from sections around Cape Farewell affected by sea ice and glacier melt with salinity <34 were analysed separately using ASW of lower salinity (diluted by using 800 mL of normal ASW topped up to 1000 mL with Milli-Q water). Performance of the Analyser The performance of the autoanalyser was monitored by producing time series of standards, QCs, CRMs and cadmium column reduction efficiency, plotted against run/analysis number. The precision of the method employed by each nutrient channel was determined by monitoring the variations of the complete set of standards, QCs and CRMs measured throughout the cruise. Accuracy of the analysis was determined via the measurement of KANSO CRMs. Results of the measurement of standards; average concentration, analytical uncertainty (sd) and precision of the analysis at the different concentration levels, are summarised in Tables 3.3.8 and 3.3.9 and shown in Figure 3.3.2. Random samples were collected in duplicate in every cast to assess reproducibility. The average difference between duplicates (n=315) were < 0.03, 0.005, 0.2, 0.05, 0.003, and 0.013 mmol L-1 for silicate, phosphate, TP, TN, nitrate+nitrite, nitrite, and ammonium, respectively. The limits of detection for the different variables, determined as twice the standard deviation of the lowest concentration standard were 0.08, 0.02, 0.18, 0.15, 0.04 and 0.07 mmol L- 1 for silicate, phosphate, TP, TN, nitrate+nitrite, nitrite, and ammonium, respectively. Problems (i) TP channel: this channel stopped working after run 3 and we were not able to fix it. This channel has never worked properly since it was first installed at NOC back in January 2013. We tested it for three months between July-September 2013 following Seal Analytical advice, but were not able to make it work. The system was then sent back to Seal Analytical headquarters in Germany where it was further tested and the method modified and improved. We tested that new method a week before packing for JR302, but did not get it to work in the lab. We have been in contact with Seal Analytical and they are planning to send an engineer/technician to carry out further work on the TP channel once back at NOC. (ii) Ammonium Channel: this channel stopped working from run 19 to 21; there was no signal from the channel despite the fact that the fluorometer and connections were working properly. Following some tests by MS, it was found that some batches of the main fluorescence reagent, orthophthalaldehyde (OPA), were most likely degraded and thus the reaction for florescent detection of ammonium was not occurring. Due to the OPA being a hazardous material that requires storage at less than 5ºC, this reagent was airfreighted just a few days prior to the team joining the ship. Unfortunately, the shipping company re-packed our boxes and did not label them properly. As a result, upon delivery to the ship there was confusion as to what boxes contained temperature-sensitive reagents and thus they were not stored in the fridge for about two days. This seems to have affected some of the OPA. Another problem found with this channel is that clogs tend to form within the manifold and within the fluorometer, possibly due to a combination of heat and reaction of residual chemical reagents mixed with washing/cleaning solutions. It was observed that clogging could be diminished by cleaning the system after switching off the heater and allowing it to cool down to room temperature. By station 216 the gain of the ammonium channel had increased from 3 or 4 (as initially) to over a hundred, rendering the measurements unreliable despite the preparation of several new OPA solutions. Thus, we were not able to measure ammonium from CTD cast 216 onwards. (iii) Cadmium column on the nitrate+nitrite channel: For reasons we do not fully understand, any newly installed cadmium column on this channel seems lose its reduction efficiency from the start (see Figure 3.3.3). By experience using autoanalysers in previous cruises we know that the life span of a new cadmium column is approximately 2 to 3 weeks depending on number of samples analysed. However, on the AA3 the efficiency starts to decrease from the moment the column is installed. What is most puzzling is the fact that once the reduction efficiency decreased below 90%, the cadmium column was swapped to the TN channel, where it performed at 100% for far longer (1-1.5 weeks); this despite having been used for 3 or 4 days in the nitrate+nitrite. Also intriguing is the fact that the CRMs and QCs continue to produce reliable results. Thus, rather than using the nitrate to nitrite ratio of the reduction efficiency standards as a way of monitoring the performance of the cadmium column, we decided to replace any new column after 3-4 days and then switch it over to the TN channel where it performed well. When we first noticed this problem, CTD casts 30 and 31 (run 11), and casts 32 and 33 (run 12) had been affected. By measuring CRMs in every run we were able to detect when the reduction efficiency of the cadmium column affected the results. We were then able to correct affected stations using a correction factor determined from the ratio of the average results of KANSO CRMs of non-affected runs relative to those affected. By re-evaluating the data, we concluded this resulted in nitrate+nitrite (or TN) profiles consistent with neighbouring stations which were not affected by the problem. Table 3.3.10 lists stations that were affected by low reduction efficiency and correction factors employed. Table 3.3.7: Calibration and QCs analysis template. ID Description Comment ————————————————————————— ————————————————————————————————— ———————————————————————— Primer Initial peak identified by Followed by a the AA3 software as the start null (or wash) of a run. 2 Drifts Separate standard of constant Followed by a null concentration used by the soft- ware in combination with ‘baseline’ checks to correct for potential drifts of the baseline. The first drift is specified as a null since it may be affected by carry over and thus is not taken into account by the software. 3 x STD 1 The first standard is specified Followed by a null as a null since it may be affec- ted by carry over and thus is not taken into account by the software. 3 x STD 2 As above. Followed by a null 3 x STD 3 As above. Followed by a null 3 x STD 4 As above. Followed by a null 3 x STD 5 As above. Followed by a null 2 Drifts As for the drifts above. Followed by 2 nulls Baseline Baseline check Followed by 1 null 4 x 30 mmol L-1 NO2- STD The first is specified as a null Cadmium column efficiency test 3 x 30 mmol L-1 NO3- STD Cadmium column efficiency test. Followed by a null 2 x GMP The first is specified as a null Followed by a null 2 x Ur The first is specified as a null Followed by a null 2 x AMP The first is specified as a null Followed by a null 2 x ATP The first is specified as a null Followed by a null 2 x Caff The first is specified as a null Followed by a null 2 x Hansell’s Lab CRM The first is specified as a null Followed by a null surface 2 x Hansell’s Lab CRM The first is specified as a null Followed by a null deep 2 x KANSO CRM The first is specified as a null Followed by a null 2 Drifts The first is specified as a null Followed by 2 nulls Baseline Baseline check Followed by a null Samples Ordered from surface to deep Samples from CTD casts samples to avoid cross contamina- were separated by Drifts tion and grouped by CTD cast. and baselines as above. Pairs of STD 1 to 5 To test consistency with stan- Followed by Drifts and dards specified as calibrants baseline check. in the software. End of run Table 3.3.8a: Mean and variation of all calibration standards measured for initial standard concentrations (runs 1-18), and precision of the analysis at each concentration (mmol L-1). Note that TP was included in runs 1-3 only. | Si(OH)4 Prec.| PO43- Prec.| TP Prec.| TN Prec. ————— | ——————————————— | —————————————— | —————————————— | ———————————————— Std 1 | 1.03±0.06 6.3 | 0.24±0.02 7.4 | 0.29±0.01 4.6 | 1.30±0.12 9.0 Std 2 | 5.07±0.08 1.6 | 0.74±0.01 1.7 | 0.73±0.02 2.7 | 6.52±0.11 1.7 Std 3 | 10.03±0.21 2.1 | 1.51±0.04 3.1 | 1.41±0.04 3.1 | 12.96±0.25 1.9 Std 4 | 20.15±0.21 1.0 | 3.09±0.05 1.6 | 2.94±0.01 0.4 | 25.63±0.27 1.0 Std 5 | 29.90±0.17 0.6 | 4.95±0.04 0.8 | 5.07±0.01 0.2 | 38.03±0.27 0.7 Table 3.3.8b: Mean and variation of all calibration standards measured for initial standard concentrations (runs 1-18), and precision of the analysis at each concentration (mmol L-1). | NO3+NO2 Prec.| NO2 Prec.| NH4 Prec. ————— | ———————————————— | —————————————— | ——————————————— Std 1 | 0.98±0.10 10.4 | 0.09±0.01 9.7 | 0.08±0.03 32.4 Std 2 | 5.69±0.14 2.4 | 0.50±0.01 2.3 | 1.00±0.03 3.2 Std 3 | 11.34±0.24 2.1 | 1.00±0.02 1.7 | 2.04±0.05 2.3 Std 4 | 22.38±0.14 0.6 | 2.02±0.02 1.0 | 3.56±0.04 1.1 Std 5 | 32.69±0.19 0.6 | 2.99±0.02 0.6 | 4.97±0.04 0.8 Table 3.3.9a: Mean and variation of all calibration standards measured for second standard concentrations (runs 19-54), and precision of the analysis at each concentration (mmol L-1). | Si(OH)4 Prec.| PO43- Prec.| TP Prec. | TN Prec. ————— | ——————————————— | —————————————— | ———————————— | ——————————————— Std 1 | 1.00±0.04 3.9 | 0.11±0.01 8.7 | not analysed | 1.37±0.09 6.6 Std 2 | 5.08±0.03 0.6 | 0.48±0.01 1.9 | not analysed | 5.88±0.14 2.3 Std 3 | 10.13±0.07 0.7 | 0.98±0.02 1.9 | not analysed | 11.83±0.20 1.4 Std 4 | 20.10±0.09 0.5 | 1.99±0.02 1.1 | not analysed | 23.89±0.17 0.7 Std 5 | 39.94±0.12 0.3 | 3.02±0.02 0.7 | not analysed | 36.25±0.23 0.6 Table 3.3.9b: Mean and variation of all calibration standards measured for second standard concentrations (runs 19-54), and precision of the analysis at each concentration (mmol L-1). Note that NH4 was included in runs 22-52 only. | NO3+NO2 Prec.| NO2 Prec.| NH4 Prec. ————— | ——————————————— | ——————————————— | ——————————————— Std 1 | 1.06±0.08 7.3 | 0.10±0.02 15.8 | 0.12±0.03 28.0 Std 2 | 5.52±0.12 2.2 | 0.50±0.01 1.4 | 0.48±0.02 5.0 Std 3 | 11.14±0.20 1.8 | 1.00±0.01 1.5 | 0.99±0.02 2.3 Std 4 | 22.18±0.14 0.6 | 2.00±0.02 0.8 | 2.04±0.03 1.3 Std 5 | 32.93±0.17 0.5 | 3.00±0.01 0.5 | 2.99±0.02 0.6 Table 3.3.10: Correction factors used to correct data affected by low reduction efficiency of the cadmium column in the nitrate+nitrite channel and TN channel. Channel | Run No CTD casts Correction factor ——————————————— | —————— —————————— ————————————————— Nitrate+nitrite | 11 30 to 31 1.067 Nitrate+nitrite | 12 32 to 33 1.168 Nitrate+nitrite | 47 170 to 180 1.09 Nitrate+nitrite | 48 181 to 185 1.14 Nitrate+nitrite | 49 186 to 191 1.12 Nitrate+nitrite | 51 198 to 208 1.046 Nitrate+nitrite | 52 209 to 215 1.043 Nitrate+nitrite | 53 216 to 224 1.062 TN | 14 37 to 40 1.089 Figure 3.3.2a: Time series of standards set up as calibrants for the analysis (black |symbols) and measured as unknowns at the end of each run (blue symbols). Error bars show the standard deviation of the mean of all runs (n=54) Figure 3.3.2b: Time series of standards set up as calibrants for the analysis (black symbols) and measured as unknowns at the end of each run (blue symbols). Error bars show the standard deviation of the mean of all runs (n=54) Figure 3.3.3: The efficiency of the cadmium column in reducing nitrate to nitrite is tested by measuring a nitrite and nitrate standard of similar concentration (~30 mmol L-1). The ratio of nitrate to nitrite expressed as percentage (%) provides an indication of the reduction efficiency. The concentration of both standards may not be exactly the same, resulting in a ratio slightly higher or lower or than 1 (or lower than 100%). Knowing this, the nitrate to nitrite ratio of a newly installed cadmium column is expected to remain relatively constant. 7 new cadmium columns were installed during JR302. It can be seen that any new column installed (open diamonds close to 100% efficiency) in the nitrate+nitrite channel lost its reduction efficiency immediately. This column, when swapped to the TN channel, performed well (slightly above 100%, black dots). 3.4 Carbonate system measurements Eithne Tynan, Rebecca Garley, Alex Griffiths and Claudia Fry 3.4.1 DIC/TA Sampling protocol Samples for total alkalinity (TA) and dissolved inorganic carbon (DIC) were drawn from the Niskin bottles with a piece of Tygon tubing into borosilicate glass bottles following best practices (Dickson et al 2007). Most bottles were 250ml but for every cast two 500ml bottles were taken at an upper water column and deep water column depth to test instrument precision. Additionally, the surface and deepest depths were sampled as duplicates in two 250 ml bottles, to test for sampling error. All samples were immediately poisoned with 50ul of a saturated mercuric chloride solution (100ul for 500ml bottles) after leaving a headspace of 1% of the volume in each bottle to allow for thermal expansion. Samples were taped and stored in a cool dark place until analysis. 3.4.2 Analysis Two VINDTA 3C system (Marianda, Kiel) were brought to sea to analyze DIC and TA on board. VINDTA #24 was connected to a CM5014 CO2 coulometer (UIC, Inc.) and VINDTA #38 was connected to a newer CM5015 CO2 coulometer (UIC, Inc.). Both these coulometers have the CM5011 emulation software. For DIC analysis, samples are warmed in a water bath for at least 30 mins before analysis. A set volume of the sample (~20ml) is acidified by addition of excess 10% phosphoric acid, which converts all inorganic carbon species to CO2. This is carried into the coulometric cell by an inert carrier gas (CO2-free N2 that is first passed through a magnesium perchlorate and soda lime scrubber), and a coulometric titration deter- mines the amount of CO2, which is equal to DIC. For TA determination, small increments of 0.1 M hydrochloric acid are added to a set volume of sample (~100ml) while the electromotive force is measured by a glass and reference electrode system. The amount of acid added to reach the carbonic acid equivalence point is equal to the TA. Once analysis started and on testing with the same batch of seawater, it was noticed that VINDTA #38 had a considerable DIC drift, with values decreasing by 10umol every 10-15 samples. When investigating into the cause of this, and after switching the coulometers on the two systems, the 5015 coulometer was identified as the source of this drift. UIC were contacted and after failed attempts to correct this it was decided to leave CM5015 and send it back to UIC after the cruise. In order to maximize the number of samples analyzed for the rest of the cruise DIC was run on VINDTA #24 connected to the CM5014 coulometer and TA was run on VINDTA #38. DIC titrations are quicker than TA so samples for TA would accumulate during the run. However when changing the coulometric cell for DIC was required, the majority of TA samples were run by the time the new cell was prepared and settled. This set-up allowed a throughput of approximately 50 samples per 24 hours. On the fourth week of the cruise, the DIC titrations started to be extremely noisy with alternating end- points of 0 and ~100. Once again, electronic issues with the coulometer were identified but on this occasion it was possible to correct them on the ship and mainly consisted of adjusting the voltages on some of the coulometer components. The CM5014 will need a recalibration after the cruise, but this should not affect results as it just produces an offset in the measurements that is corrected for by running CRMs. Regular measurements of both DIC and TA were made from batch 135 and 136 Certified Reference Material (CRM) from A. G. Dickson (Scripps Institution of Oceanography) and used to calibrate the results as follows: DICsample, corrected = DICsample, measured x (DICCRM, certified/DICCRM, measure) TAsample, corrected = TAsample, measured x (TACRM, certified/TACRM, measured) No difference in correction factors was found between the two batches. To obtain the final results in units of µmol kg-1, a correction for density (ρ) due to salinity (S) variations was then applied using salinity measured from Niskin bottle samples and an equation of the form (Zeebe and Wolf-Gladrow 2001): ρsea water, 25°C = ρpure water, 25°C + AS + BS1.5 + CS2 For DIC, CRMs were run at the beginning, middle and end of each coulometer cell. Cell solution was replaced every 12 hours with average titration times of 10 minutes (ranged from 8-17 mins). The average value of the three CRMs during the cell session was used to calculate the correction factor for each cell (shown on Figure 3.4.1). Before cell session 40 correction factors were centred around 1.0333, while after it they were centred around 1.0343. This shift was due to the adjustment of the electronics on the CM5014 coulometer due to the noise described previously. While recalibration of the unit will be needed after the cruise, the spread of the correction factors appeared to decrease after electronic adjustment. For TA measurements, one 20L batch of 0.1M HCl acid was prepared at the beginning of the cruise and stored in a plastic carboy in the fumehood. Bottles for the titrino were subsampled from this throughout the cruise. VINDTA 24 was only used for TA in the first two weeks of the cruise when all TA measurements were switched to VINDTA 38. Figure 3.4.2 shows the correction factors for TA obtained from the CRMs run during each of the acid bottles. The decrease in the correction factor for VINDTA 38 throughout the cruise can be attributed to the evaporation of the bulk batch of acid in fumehood and not to a drift of the instrument itself. Therefore each set of samples run on a particular acid bottle was corrected with the average correction factor obtained from that bottle. For TA determination, small increments of 0.1 M hydrochloric acid are added to a set volume of sample (~100ml) while the electromotive force is measured by a glass and reference electrode system. The amount of acid added to reach the carbonic acid equivalence point is equal to the TA. Once analysis started and on testing with the same batch of seawater, it was noticed that VINDTA #38 had a considerable DIC drift, with values decreasing by 10umol every 10-15 samples. When investigating into the cause of this, and after switching the coulometers on the two systems, the 5015 coulometer was identified as the source of this drift. UIC were contacted and after failed attempts to correct this it was decided to leave CM5015 and send it back to UIC after the cruise. In order to maximize the number of samples analyzed for the rest of the cruise DIC was run on VINDTA #24 connected to the CM5014 coulometer and TA was run on VINDTA #38. DIC titrations are quicker than TA so samples for TA would accumulate during the run. However when changing the coulometric cell for DIC was required, the majority of TA samples were run by the time the new cell was prepared and settled. This set-up allowed a throughput of approximately 50 samples per 24 hours. On the fourth week of the cruise, the DIC titrations started to be extremely noisy with alternating end- points of 0 and ~100. Once again, electronic issues with the coulometer were identified but on this occasion it was possible to correct them on the ship and mainly consisted of adjusting the voltages on some of the coulometer components. The CM5014 will need a recalibration after the cruise, but this should not affect results as it just produces an offset in the measurements that is corrected for by running CRMs. Regular measurements of both DIC and TA were made from batch 135 and 136 Certified Reference Material (CRM) from A. G. Dickson (Scripps Institution of Oceanography) and used to calibrate the results as follows: DICsample, corrected = DICsample, measured x (DICCRM, certified / DICCRM, measure) TAsample, corrected = TAsample, measured x (TACRM, certified / TACRM, measured) No difference in correction factors was found between the two batches. To obtain the final results in units of μmol kg-1, a correction for density (ρ) due to salinity (S) variations was then applied using salinity measured from Niskin bottle samples and an equation of the form (Zeebe and Wolf-Gladrow 2001): ρsea water, 25°C = ρpure water, 25°C + AS + BS1.5 + CS2 For DIC, CRMs were run at the beginning, middle and end of each coulometer cell. Cell solution was replaced every 12 hours with average titration times of 10 minutes (ranged from 8-17 mins). The average value of the three CRMs during the cell session was used to calculate the correction factor for each cell (shown on Figure 3.4.1). Before cell session 40 correction factors were centred around 1.0333, while after it they were centred around 1.0343. This shift was due to the adjustment of the electronics on the CM5014 coulometer due to the noise described previously. While recalibration of the unit will be needed after the cruise, the spread of the correction factors appeared to decrease after electronic adjustment. For TA measurements, one 20L batch of 0.1M HCl acid was prepared at the beginning of the cruise and stored in a plastic carboy in the fumehood. Bottles for the titrino were subsampled from this throughout the cruise. VINDTA 24 was only used for TA in the first two weeks of the cruise when all TA measurements were switched to VINDTA 38. Figure 3.4.2 shows the correction factors for TA obtained from the CRMs run during each of the acid bottles. The decrease in the correction factor for VINDTA 38 throughout the cruise can be attributed to the evaporation of the bulk batch of acid in fumehood and not to a drift of the instrument itself. Therefore each set of samples run on a particular acid bottle was corrected with the average correction factor obtained from that bottle. Figure 3.4.1: Correction factors per coulometer cell run on VINDTA 24. Replicate analysis from a 500ml bottle were used to evaluate precision of the instruments for both TA and DIC. Duplicate analysis (samples drawn on two different 250ml bottles from the same niskin bottle) were used on DIC to check for sampling technique, while on TA it was used to check no change in concentration occurred between the time the bottle had been run for DIC and running on TA. Figure 3.4.3 shows the absolute differences between duplicate and replicate measurements. The standard deviation of the duplicates was taken as the precision of the measurements for this cruise. In total 2167 samples were collected for DIC/TA on JR302, and 1616 of these were analysed on board. 551 samples were taken back to the lab in Southampton for analysis there. Figure 3.4.2: TA correction factors per acid bottle used for the two VINDTAs where TA was run. Table 3.4.1: TA and DIC Duplicate and replicate statistics Replicates Duplicates Average St.Dev. Average St.Dev. ——— ———————————————— ———————————————— TA 1.27 1.07 2.00 1.46 DIC 1.60 1.16 2.22 1.64 Figure 3.4.3: Distribution of absolute difference between duplicate and replicate measurements. 3.4.2: Isotope Samples Samples for δ13C of DIC and δ18O of H2O were collected during the cruise and will be analyzed at the NERC Isotope Geosciences Laboratory (NIGL) in East Kilbride. Samples for δ13C were collected in either 100 ml soda-lime glass bottles or 250 ml borosilicate glass bottles. Preparation for storage was as recommended by Dickson et al. (2007) for DIC samples: soon after collection, a 1% bottle volume headspace was created and 20 μl (for 100ml bottles) or 50 μl (250 ml bottles), of saturated mercuric chloride were added. The stopper was dried and Apiezon L grease was added to make the seal air-tight. Electrical tape was wrapped around the bottle and stopper to hold the lid shut. Samples were then stored at 4°C. Samples for δ18O were collected in 5 ml glass vials. These vials were filled completely and closed with the screw cap top. Parafilm was put around the top before wrapping with electrical tape. Samples were stored at 4° C to avoid evaporation. References Dickson, Andrew G., Christopher L. Sabine, and J. R. Christian. (2007). Guide to Best Practices for Ocean CO2 Measurements. PICES Special Publication 3. Zeebe, Richard E., and D. A. Wolf-Gladrow. (2001). CO2 in Seawater: Equilibrium, Kinetics, Isotopes. Elsevier Oceanography Series 65. 3.5 Chlorofluorocarbons (CFCs) and sulphur hexafluoride (SF6) measurements Marie-José Messias, Tobia Tudino, Pete Mead, Lilo Henke and Gary Murphy A series of three halocarbons (dichlorodifluoromethane – CFC-12, trichlorofluoromethane - CFC-11, and trichlorotrifluoroethane - CFC-113) and sulphur hexafluoride (SF6) were measured on board by a purge-and-trap gas chromatographic method. The method combines the Lamont Doherty Earth Observatory CFC method [Smethie et al., 2000] and the Plymouth Marine Laboratory SF6 method [Law et al. 1994] tied together with a common valve for the introduction of gas and water samples. This system has the advantage of a simultaneous analysis of SF6 and halocarbons from the same water sample with a running time per sample of ~20 minutes when CCl4 is not measured. The system was set up in the temperature controlled NMF container # 200227 which was installed on the after deck of the JCR. 3.5.1 Sample collection Water samples were collected from 10 litre bottles as soon as the CTD sampling rosette was on board. As per WOCE protocol, they were the first samples drawn. The Niskin nitrile 'O' rings were first washed in isopropanol and baked in a vacuum oven for 24 hours to remove susceptible contamination before installation in individual Niskin bottles. The trigger system of the bottles was external stainless steel springs. Water samples were collected in 500 ml ground glass stoppered bottles that were filled from the bottom using Tygon tubing and overflowed at least 2 times to expel all water exposed to the air. Immediately after sampling, the glass bottles were immersed in a cool box of clean cold deep seawater and stored in the cold room (~5°C) to prevent degassing until their analysis. For air sampling, ¼” o.d. Dekabon tubing was run from the system to the monkey island of the ship. Air was pumped through the line to the instrument using a DA1 SE Charles Austen pump, with the line being flushed for approximately 30 minutes before beginning analysis. 3.5.2 Analysis technique Sample analysis was performed on board as soon as possible after collection using a coupled SF6 and CFCs system with a common valve for the introduction of gas and water samples. Samples were introduced to the system by applying nitrogen (N2) pressure to the top of the sample bottles, forcing the water to flow through and fill a 27 cm3 calibrated volume for CFCs and a 300 cm3 volume for SF6. The measured volumes of seawater were then transferred to separate purge and trap systems, before being stripped with N2 and trapped at -100°C on a Unibeads 3S trap (for CFCs) and at -80 °C on a Porapak Q trap (for SF6) each immerged in the headspace of liquid nitrogen. Each purge and trap system was interfaced to an Agilent 6890N gas chromatograph with electron capture detector (GC- ECD). The traps were heated to 100° C for CFCs and 65°C for SF6 and injected into the respective gas chromatographs. The SF6 separation was achieved using a molecular sieve packed 2 meters main column and 1meter buffer column. The CFCs separation was achieved using a 1m Porasil B packed pre-column and a 1.5m carbograph AC main column. The carrier gas was pure nitrogen, which was cleaned by a series of purity traps. Liquid nitrogen was used as the cryogenic cooling material for the sample traps, and was provided by an on-board liquid nitrogen generator located in the deck workshop of the JCR. 3.5.3 Calibrations The CFCs and SF6 concentrations in air and water were calculated using an external gaseous standard. The standards supplied by NOAA (Brad Hall, December 2008 and 2009) correspond to clean dry air slightly enriched in SF6, CFC-11 and CCl4 in 29L Aculife-treated aluminum cylinders (Table 3.5.1). The calibration curves were made by multiple injections of different volumes (0.1, 0.25, 0.3, 0.5, 1, 2, 3, 5, 8 ml) of standard that span the range of tracers measured in the water. Complete calibration curves were made at the beginning, middle and end of the cruise (Figure 3.5.1). The changes in the sensitivity of the system for each compound were tracked by injections of a fixed volume of standard gas (Figure 3.5.2) and used to adjust the calibration curves respectively. Figure 3.5.1: Calibration curves for CFC-11, CFC-12, CFC-113 and SF6 at the beginning of the cruise (8th of June 2014). Table 3.5.1: Concentrations of the used NOAA standards | NOAA2008 AAL-70510 | NOAA2009 AAL-072073 ————————|————————————————————|———————————————————— | PPT | STDVE | PPT | STDVE ————————|————————————————————|———————————————————— SF6 | 7.27 | 0.02 | 10.15 | 0.03 CFC-11 | 1010 | 5 | 1003 | 6 CFC-12 | 510.6 | 0.8 | 532 | 1.4 CFC-113 | 75.2 | 0.28 | 76.9 | 0.2 Figure 3.5.2: Instrument response as for the analysis of 1ml standard analyses (NOOA 2009 and 2008) for CFC-12, CFC-11, CFC-113 and SF6. The time is the number of days from 1rst of January 2014. Abrupt changes noticeable for CFC-12 and CFC- 113 correspond to instrument interventions. The gradual loss of sensitivity for CFC-11 was due to the deterioration of the Porasil B column changed days 180. 3.5.4 Precision and accuracy The precision (or reproducibility) for the water samples measurements can be determined from replicate samples drawn on the same Niskin. 5% of the samples were duplicate samples drawn randomly from the rosette along the cruise when possible (time and sampling permitting). This gave measurement precisions for SF6 of 1.05 % for surface values & 0.011 fmol/kg for values < 0.1 fmol/kg, for CFC-12 0.95 % for surface values & 0.003 pmol/kg for values < 0.1 pmol/kg, for CFC-11 1.1 % for surface values & 0.006 pmol/kg for values < 0.1 pmol/kg and for CFC-113 1.5% for surface values & 0.001 pmol/kg for values < 0.1 pmol/kg. The reproducibility for tracer concentration was also estimated at the test station (#34) where all Niskin bottles were fired at the same depth (2700 dbars) and only one sample was drawn per Niskin (Table 3.5.2). Table 3.5.2: Results from the test station (#34) for 24 samples, mole/kg. SF6 CFC-12 CFC-11 CFC-113 ————— ————————— ————————— ————————— ————————— MEAN 7.084E-16 1.429E-12 2.96E-14 1.347E-13 STDEV 1.873E-17 5.491E-15 4.919E-15 2.168E-15 The blank correction is to compensate for any trace CFCs/SF6 originating from the sampling bottles, handling and from the measurements procedure. This correction is normally estimated from analysis of either samples collected in water that are free of CFCs or water collected after sparging all the tracers out of a niskin bottle. System blanks were determined through the analysis of water samples that had been purged of all dissolved gases. Sparge efficiencies were investigated through the continual resparge of a single sample until results did not change (having reached the system blank) at a number of different flow rates. Initial results for general lab conditions are reported in Table 3.5.3. Table 3.5.3: Sparge efficiency Tracer Sparge efficiency ——————— ————————————————— SF6 97.5 % CFC-12 98.5 % CFC-11 99.2 % CFC-113 100 % 3.5.5 Preliminary data 137 stations were sampled [1: 10, 12, 14, 16, 18:19, 21, 22, 23, 24, 26, 27, 28, 30:34, 36:38, 40, 42:50, 52:55, 57, 59:61, 63, 65:66, 68, 71, 73, 75, 78:79, 82, 84:89, 91:94, 96, 99, 101, 103, 113:115, 117, 119:120, 124, 126, 128:130, 132:138, 140:142, 144:155,157, 171, 175, 176, 177, 180:186, 188:196, 202:206, 210:215] and analysed for CFCs and SF6. However, some stations were sampled only for the Nordics Seas Overflows because analysis time was limited. Initial results for the first transect are presented in Fig. 3.5.3. The distributions of the CFCs and SF6 seen here are largely consistent with previous studies, showing ventilation in the Labrador Sea down to 1800m and the Denmark Strait Overflow Water signal in the bottom waters. Figure 3.5.3: Preliminary plots of CFC-12 and SF6 extending from southern Labrador to the southwestern tip of Greenland across the mouth of the Labrador Sea (OSNAP West) in the Labrador Sea in Mole/kg. 3.6 Methane and Nitrous Oxide Ian Brown Nitrous oxide and methane are biogenically produced trace gases whose atmospheric concentrations are increasing at a rate in the order of 0.7 ppbv y-1. Both gases are radiatively active, contributing approximately 6% and 15% of “greenhouse effect” respectively, whilst N2O contributes to stratospheric ozone depletion and CH4 limits tropospheric oxidation capacity. The oceans are generally considered to be close to equilibrium relative to the atmosphere for both gases, however oceanic source/sink distributions are largely influenced by oxygen and nutrient status and regulatory processes are complicated and are currently not well understood. The aim for this cruise is to examine spatial variability in methane production and Nitrous oxide along the cruise track. Samples were collected from CTD stations. 1 litre samples were equilibrated with compressed air and headspace analysis performed onboard using FID-gas chromatography and ECD-gas chromatography for CH4 and N2O respectively. Atmospheric concentrations were determined by the same methods using a Tedlar bag filled with a hand pump from the bow of the ship. 3.7 Surfactants, CDOM and Pigments Bita Sabbaghzadeh The aim of this work was to investigate the vertical and horizontal distribution of natural surfactants and CDOM in North Atlantic Ocean which then will be combined with the next AMT cruise (AMT24) data to explore natural surfactants control of air-sea CO2 exchange in regions of contrasting primary productivity. Surfactants will be measured by AC Voltammetry and in order to provide some preliminary characterisation of the organic matter pool of which surfactants are a component CDOM will be determined using an ULTRAPATH system. Methods During the cruise I targeted specific stations for my analysis. For surface samples, I chose the stations which allowed me to assess the impact of variability in wind speed and its direction and also primary productivity impact on surfactant concentration and their distribution. For vertical profile water samples I selected the stations which enabled me to compare surfactant distribution between different water masses and to investigate the impact of ocean circulation. Figure 3.7.1: Location surfactant/CDOM and pigment sampling stations Surface Micro Layer (SML) samples (upper 400um) were collected using in- house constructed Garrett Screen (60cmx60cm). The screen pre-rinsed 10 times in sea water that it was about to sample and then it was allowed to drain 5s before collection start. The screen was deployed horizontally and lift through the SML and the samples were drained along one of its corners until most of the adhering water was drawn. The thickness of the SML also may vary depending on both the oceanographic and meteorological conditions at the time the samples are taken. So, the thickness of the SML was measured in two ways in every sample station; firstly, the Garrett Screen was dipped 10 times in one place and the water samples were taken each time. Then the total volume of the samples was recorded. Secondly, the screen was dipped 10 times in 10 different places around the ship and the volume of the sample from each place was recorded and then added the volume taken up. In order to minimise the disturbance to SML from the ship’s discharges at the stations, the ship went to full attention (i.e. no discharge to the sea). The vertical profile water samples were also collected during daily hydrocasts from a 24x10L water- bottle rosette fitted with a CTD probe (Sea-Bird Electronics, SBE09). Finally, the underway water samples (~6 meter depth) were collected. All the samples were made in two duplicates. Samples for surfactant analysis were collected in 15ml centrifuge tubes. For CDOM samples, 200ml borosilicate volumetric flasks were used. All the containers were pre-rinsed with 10% HCL and Milli-Q water (Millipore, model ZFSQ240P4) first and then rinsed with some samples three times prior to collection. During the sampling Nitrile Powder-Free disposable gloves were worn. One batch of CDOM samples was filtered through 0.22µm Surfactant-Free single use syringe filters (MILLEX GP, Millipore). In order to avoid contamination during the filtration process, the syringes and all containers used during filtration rinsed with 10% HCL and M.Q. three times prior to use and between each sample. A small volume of sample (~20ml) was used to rinse filters and the filtrate discarded before collection. Surfactant activity (SA) measurement SA measurements were carried out by 797 VA Computerace Voltammetry (Metrohm) with a hanging mercury drop electrode. The calibration was conducted by analysing 10ml of 0.55mol l¯¹ NaCl as the blank/reference solution and followed by adding and analysing the standard (Triton-X-100) to the initial reference solution. The surfactant activity of the sample was measured from the decrease of the capacity current over a range of potentials after 15 and 60s accumulation of surfactants at the starting potential. The potential range was between E=-0.6V at the starting point and E=-0.9998V at ending point. It has been noticed from the capacity current that the ship vibration is a potential problem. In order to minimize the vibration effect, the instrument was set up in Biology Lab (central line of the ship) and was stood on a gimballed table over some foam. However, the later results showed that the issue still exists when the winch is in operation at the stations and also low current capacity results was due to the Reference Electrode (R.E.) malfunction. Therefore, no further measurements were carried out at the stations. In this occasion, the samples were stored at -80˚C for later analyses. CDOM determination CDOM measurements were conducted by high-performance spectrophotometer (UltraPath). Absorbance spectra (250-730nm) of filtered (0.2µm) and unfiltered for SML, underway and CTD samples were measured using a 50cm pathlength, providing greater sensitivity compared to conventional 10cm pathlength spectrophotometer. The single scan mode with an average of 10 numbers of scans was applied to record the CDOM spectrums. In order to minimize the refractive index effect due to the salinity difference between seawater samples and M.Q. water, NaCl solution standards with the same salinity as the samples were used. The solutions were prepared using analytical grade NaCl dissolved in M.Q. water. To remove any organic contaminants, the salt was baked at 400˚C in advance. The absorbance of the salt solution was measured at the same time as the samples. The integration time was set to maximize the signal measured for the applied pathlength while avoiding oversaturation of the detector. Between the samples run the UltraPath was flushed with M.Q. water. The data were gathered for both filtered and unfiltered samples and will be available after calibration. Chlorophyll a measurements 3 litre water samples were collected from the depth with maximum Chlorophyll a during daily hydrocasts from Niskin bottles. Then the samples were split into pseudo-replicates of 1L and filtered through 0.22 µm pore size 25mm diameter nylon membrane filters using the vacuum pump (Millipore) at low pressure (4.2 Hg).Then the filters were folded in half twice, wrapped in aluminium foil and stored at -20˚C for later analysis. Table 3.7.1: Chlorophyll analysis: station number, Niskin bottles and the approximate depths. Station Niskin Bottle Approximate Depth(m) ——————— ————————————— ———————————————————— CTD007 21 24 CTD014 23 5 CTD021 23 20 CTD027 22 45 CTD031 23 29 CTD040 22 37 CTD046 23&24 5 CTD050 16&17 14 CTD059 22 15 CTD077 18 32 CTD084 24 7 CTD096 18 26 CTD110 16 27 CTD124 14 31 CTD133 22 24 CTD145 20 25 CTD152 21 24 CTD161 7&8 24 CTD170 21&22 25 CTD180 20&21 15 CTD186 13&14 13 CTD191 21&22 21 CTD198 21&22 27 CTD200 9&10 38 CTD206 21&22 33 CTD216 11&12 17 CTD230 7&8 13 3.8 Trace Metals Stefan Gary Samples for trace metal analysis were collected at 12 stations along the cruise (Table 3.8.1). A total of 90 125 mL polyethylene bottles were specially cleaned and completely filled with deionized water to minimize contamination during transport and storage before the cruise. Each bottle was in a plastic re- sealable bag and only removed from the bag for labeling the bottle and taking the seawater sample. After the sample was collected, the bottle was put back in the bag. Each sample was 100 mL and drawn after all the other samples were taken. For each sample, the bottle and lid were rinsed three times with the seawater from the Niskin bottle and the fourth time bottle was filled with seawater was the final sample. Immediately after sampling was finished, the freshly filled sample bottles were carried to the -18°C freezer for storage for the remainder of the cruise. Gloves were worn whenever the bottles were handled (labeling, sampling, organization in the freezer, and packing). For each cast, samples were taken on at most 7 depth levels but most frequently at 6 levels. The goal was to sample the subsurface chlorophyll maximum (if present), waters below the seasonal thermocline (~100 m), an intermediate depth (~300 – 500 m), the oxygen minimum zone (~800 m), a deeper intermediate level (~1500 m), and the bottom. On shallow stations other levels were chosen. Every cast also included at least one duplicate sample (usually two) ideally drawn from a second Niskin bottle that was fired at the same depth as the duplicated sample's Niskin bottle. This was not always possible, so if there was only one Niskin fired at each depth, then the duplicated sample was drawn from the same Niskin. The trace metal samples will be analyzed for transition metals (Ti to Zn) and the rare earth elements (La to Lu). The concentrations will be measured by the method of combined preconcentration using the SeaFAST Pico (Elemental Scientific Inc., Nebraska, USA) and analysis by ICP-MS (Thermo XSeries2). Table 3.8.1: Summary of trace metal samples by zone along the section and station number. Adjacent gray blocks indicate duplicate samples. Zone Station Samples → 1 2 3 4 5 6 7 8 ————————— ——————— ———————————————— ———— ———— ———— ———— ——— ——— —— —— OSNAPWest 12 Depth [m] 246 226 131 76 52 37 12 12 Niskin bottle # 01 04 07 09 11 13 15 16 24 Depth [m] 3452 3454 2768 1670 469 81 25 25 Niskin bottle # 01 02 05 09 15 20 23 23 40 Depth [m] 3467 3467 2051 664 330 92 37 - Niskin bottle # 01 02 09 15 17 20 22 - Green-land 107 Depth [m] 496 253 104 24 24 - - - Niskin bottle # 01 04 06 08 09 - - - OSNAPEast 89 Depth [m] 2835 1750 427 250 87 87 26 - Niskin bottle # 01 07 13 14 17 18 21 - 138 Depth [m] 2668 2568 1500 469 470 102 30 - Niskin bottle # 01 02 08 14 15 19 22 - EEL 169 Depth [m] 1206 1006 751 751 345 80 28 29 Niskin bottle # 01 04 05 06 11 17 21 22 177 Depth [m] 2413 1754 586 586 449 151 26 26 Niskin bottle # 01 06 11 11 12 15 18 18 192 Depth [m] 1788 1487 713 713 353 104 24 24 Niskin bottle # 01 04 08 08 11 14 16 17 204 Depth [m] 1789 1251 899 898 451 98 42 42 Niskin bottle # 01 05 06 07 10 17 19 20 213 Depth [m] 1915 1500 916 916 451 101 23 23 Niskin bottle # 01 05 08 09 12 17 21 22 225 Depth [m] 208 208 142 98 99 53 28 29 Niskin bottle # 01 02 03 05 06 07 09 10 3.9 Phytoplankton community structure and species identification. Mark Stinchcombe Samples for particulate organic carbon (POC), particulate organic nitrogen (PON), particulate organic phosphorous (POP), high performance liquid chromatography (HPLC), scanning electron microscopy (SEM), taxonomy (Lugols) and bacterial composition (Glutaraldehyde) were taken from approximately one station per day. In all but one station (CTD006) water was drawn from the shallowest Niskin into a 20L plastic jerrycan. For POC/PON, water was filtered onto a pre-combusted GF/F filter, rinsed with 1% HCl and then put into a cryovial. For POP, water was filtered onto a GF/F filter that had been pre-combusted, soaked in 10% HCl for 24 hours, soaked in MilliQ water for 12 hours and finally left in a second MilliQ bath until required. The filter was then rinsed with MilliQ and placed into a pre-combusted glass tube. For HPLC, water was filtered onto a normal GF/F filter, rinsed with MilliQ and placed into a cryovial. For SEM water was filtered onto a 0.8µm polycarbonate filter, rinsed with MilliQ water that had been adjusted to a pH of 7.5 with ammonia, and then placed onto a petri-slide. In all cases 500ml was filtered unless otherwise stated in Table 3.9.1. One SEM sample was not taken, from CTD022, as there was not enough water. POC/PON, POP and SEM filters were dried in an oven at 60°C for approximately 24 hours. The HPLC sample was placed straight into the -80°C freezer. A sample for taxonomy was taken by filling a 100ml amber glass with water and adding 2ml of acidified Lugols solution. These were kept at room temperature. For bacterial composition, 45-50ml was put into a 50ml centrifuge tube and 250ml glutaraldehyde was added. The lid was then put on and sealed with parafilm. The sample was left for 10-15 minutes before being placed in the -80°C freezer. Table 3.9.1: All the stations sampled for biological parameters, the associated Niskin numbers and the approximate depths the samples were taken from. Approximate Station Niskin depth from wire out (m) POC/PON POP HPLC SEM Lugols Glut. ——————— —————— ———————————— ——————— ——— ———— ————— —————— ————— CTD005 24 5 √ √ √ √ √ √ CTD006 20 29 √ √ √ √ √ √ CTD011 24 5 √ √ √ √ √ √ CTD022 24 5 √ √ √ X √ √ CTD023 24 5 √ √ √ √ √ √ CTD028 24 0 √ √ √ √ √ √ CTD033 24 11 √ √ √ √ √ √ CTD038 24 10 √ √ √ √ √ √ CTD042 24 10 √ √ √ √ √ √ CTD043 24 5 √ √ √ √ √ √ CTD048 24 2 √ √ √ √ √ √ CTD049 24 1 √ √ √ √ √ √ CTD056 24 5 √ √ √ √ √ √ CTD062 24 5 √ √ √ 180ml √ √ CTD068 24 10 √ √ √ √ √ √ CTD071 24 5 √ √ √ √ √ √ CTD075 24 5 √ √ √ √ √ √ CTD078 24 0 √ √ √ √ √ √ CTD088 24 5 √ √ √ √ √ √ CTD093 24 0 √ √ √ √ √ √ CTD099 24 0 √ √ √ √ √ √ CTD104 24 0 √ √ √ √ √ √ CTD116 24 0 √ √ √ √ √ √ CTD119 24 0 √ √ √ √ √ √ CTD128 16 0 √ √ √ √ √ √ CTD137 19 0 √ √ √ √ √ √ CTD142 21 5 √ √ √ √ √ √ CTD148 19 0 √ √ √ √ √ √ CTD156 19 0 √ √ √ √ √ √ CTD166 12 0 √ √ √ √ √ √ CTD177 20 10 √ √ √ √ √ √ CTD183 19 0 √ √ √ √ √ √ CTD196 19 0 √ √ √ √ √ √ CTD202 14 0 √ √ √ √ √ √ CTD211 19 0 √ √ √ √ √ √ CTD226 10 5 √ √ √ √ √ √ 3.10 Iodine Isotope Sampling Mark Stinchcombe 45 samples for 129Iodine were taken along the cruise track. These consisted of 5 profiles, 8 depths each, and 5 surface samples taken from the shallowest Niskin on the associated cast. Water was drawn from the required depths into 200ml polyethylene bottles and stored at approximately 4°C in the dark. The required stations can be seen in Figure 3.10.1, the closest station to these locations were chosen and sampled as per our instructions from Dr Maria Villa from the University of Seville. If the required sampling depth was not available, the Niskin closest to this depth was chosen instead. The samples will be returned the University of Sevilla for analysis. The actual stations and depths sampled can be seen in Table 3.10.1. Figure 3.10.1: Location map of the required sampling stations for 129I including the required depths at these stations. Table 3.10.1: The actual stations that were sampled for 129I and the associated Niskin and approximate depth of those samples. Approximate Station Niskin depth from 129Iodine wire out (m) ——————— —————— ———————————— ————————— CTD005 24 5 √ CTD024 1 3450 √ CTD024 8 1920 √ CTD024 10 1420 √ CTD024 12 920 √ CTD024 14 670 √ CTD024 16 360 √ CTD024 19 120 √ CTD024 24 5 √ CTD032 1 ? √ CTD032 8 ? √ CTD032 10 ? √ CTD032 12 ? √ CTD032 14 ? √ CTD032 15 ? √ CTD032 19 ? √ CTD032 24 ? √ CTD042 1 3172 √ CTD042 7 2055 √ CTD042 10 1455 √ CTD042 14 891 √ CTD042 15 667 √ CTD042 16 472 √ CTD042 20 92 √ CTD042 24 10 √ CTD094 1 3087 √ CTD094 6 2000 √ CTD094 8 1500 √ CTD094 10 1000 √ CTD094 11 750 √ CTD094 12 500 √ CTD094 15 100 √ CTD094 22 0 √ CTD116 1 2650 √ CTD116 4 2100 √ CTD116 6 1500 √ CTD116 8 1000 √ CTD116 9 750 √ CTD116 10 500 √ CTD116 13 100 √ CTD116 19 0 √ CTD136 19 0 √ CTD147 21 0 √ CTD156 19 0 √ CTD211 18 0 √ 4. UNDERWAY MEASUREMENTS Team Physics 4.1 SCS data streams The SCS data streams (ashtech [nav/ash], ea600 [sim], anemometer [met/surfmet], oceanlogger [ocl], emlog-vhw [chf], gyro [nav/gyro], seatext-gell [nav/seapos], em122 [em122], seatext-hdt [nav/seahead]) were processed on fola during the cruise. Most were processed in 24-hour segments, using m_jr302_daily_processing.m, with cleaning and appending as required. Winch data were processed by CTD station as part of the standard CTD processing. Daily processing generates a best navigation file, data/nav/seapos/bst_jr302_01.nc. The final surface meteorological data file is data/met/surfmet/met_jr302_truav.nc. Other final, cleaned and appended files from the daily processing are: chf_jr302_01.nc ocl_jr302_01_medav_clean_cal_botcompare.nc em122_jr302_01.nc ocl_jr302_01_medav_clean_cal.nc ocl_nav_jr302_01.csv gyr_jr302_01.nc sim_jr302_01_nav_cordep.nc Notes on the processing stages of these underway data are available in the cruise report for JR306 (Firing, 2015). 4.2 VMADCP 4.2.1 Introduction A 75 kHz RD Instruments Ocean Surveyor (OS75, – model 71A-1029-00, SN 2088) ADCP was used during this cruise. The OS75 is capable of profiling to deeper levels in the water column than the previous 150 kHz ADCP and can also be configured to run in either narrowband or broadband modes. 4.2.2 Instrumentation The OS75 unit is sited in the transducer well in the hull of the JCR. This is flooded with a mixture of 90% de-ionised water and 10% monopropylene glycol. The OS75 transducer on the JCR is aligned at approximately 60 degrees relative to the centre line. The hull depth was 6.47m. Combined with a value for the distance of the transducer behind the seachest window of 100-200mm and a window thickness of 50mm, this implies a transducer depth of 6.3m. The OS75 causes interference with most of the other acoustic instruments on JCR, including the EM120 swath bathymetry system. To circumvent this, the ADCP pinging can be synchronised with the other acoustic instruments using the SSU. The heading feed to the OS75 is the heading from the Seapath GPS unit. 4.2.3 Configuration The OS75 was controlled using Version 1.42 of the RDI VmDas software. The OS75 ran in narrowband with bottom-tracking on and narrowband with bottom-tracking off. The ‘set modes’ configuration files, as described in JR195 report, were used during the cruise. Salinity at the transducer was set to zero, and Beam 3 misalignment was set to 60.08 degrees. Data logging was stopped and restarted once a day to keep files to a manageable size for processing. 4.2.4 Outputs The ADCP writes files to a network drive that is samba-mounted from the Unix system. The raw data (.ENR and .N1R) are also written to the local PC hard drive. For use in the matlab scripts the raw data saved to the PC would have to be run through the VMDas software again to create the .ENX files. When the Unix system is accessed (via samba) from a separate networked PC, this enables post- processing of the data without the need to move files. Output files are of the form JRNNN_XXX_YYYYYY.ZZZ, where XXX increments each time the logging is stopped and restarted, and YYYYYY increments each time the present filesize exceeds 10 Mb. ZZZ are the filename extensions, and are of the form:- .N1R (NMEA telegram + ADCP timestamp; ASCII) .ENR (Beam co-ordinate single-ping data; binary). These two are the raw data, saved to both disks .VMO (VmDas configuration; ASCII) .NMS (Navigation and attitude; binary) .ENS (Beam co-ordinate single-ping data + NMEA data; binary) .LOG (Log of ADCP communication and VmDas error; ASCII) .ENX (Earth co-ordinate single-ping data; binary). This is read by matlab processing .STA (Earth co-ordinate short-term averaged data; binary) .LTA (Earth co-ordinate long-term averaged data; binary). .N1R and .ENR files are saved to the secondary file path and can be reprocessed by the software to create the above files. 4.2.5 CODAS/Hawaii processing. The data were processed using the CODAS software. The processing route can be summarised as copying the raw files, converting them into a working format, merging navigation data, deriving velocities, quality control, and conversion of data to matlab and netcdf files. Calibration information can be obtained after several water and bottom-track data files have been processed; calibration can be performed at any time during the cruise or left until the end. While the ship is steaming, the main signal that the ADCP instrument records is the ship speed. 12 knots (6 m/s) is 1-2 orders of magnitude greater than the water velocity. This velocity is removed using GPS derived ship velocities but there is clearly the potential for a significant error associated with this process as the output data is the small difference between two large numbers. To address this, the velocity of the bottom can be measured and compared directly to the GPS velocity of the ship. This should give the amplitude error for the ADCP and the misalignment with the ship heading. This only works in water where the bottom track ping can reach the sea bed – 800m or shallower. In deeper water the processing uses changes in the ship velocity to assess what proportion of the ship velocity is contaminating the calculated water velocity. This calculation necessarily invokes assumptions that the true water velocity is relatively constant in space (if slowing down) or time (if turning round) and is therefore considered less precise than bottom tracking. A large number of water track data were collected, from slowing down and speeding up from stations. Note that this software sometimes outputs a decimal day, calculated from time in seconds since the start of the year. Decimal day is 0.5 for noon on the 1st January: this contrasts with a jday of 1.5 for noon on the 1st January. Below is a summary of the processing steps. 1) Created once at start of cruise ~/data/vmadcp/jr302_os75 ~/data/vmadcp/jr302_os75/rawdata 2) For dataset NNN (eg NNN = 002), copy raw data files (ENX, N1R, etc) from /mnt/data/cruise/jcr/current/adcp into /local/users/pstar/jr302/data/vmadcp/jrCCC_os75/rawdata file names like OS75_JR302NNN_000000.ENX NNN increments each time the ADCP logging is re-started. Data logging was stopped and started once every day. The 000000 increments each time a new file is started, when the previous one reaches 10 Mb. All raw files are automatically transferred to /mnt/data/cruise/jcr/current/adcp (i.e. on jrlb) 3) cd ~pstar/jr302/data/vmadcp/jr302_os75 cshell script in /local/users/pstar/cruise/data/exec vmadcp_movescript redistributes raw data from rawdata to rawdataNNN; rawdataNNN is created if necessary (may need to edit movescript so that it parses the file names correctly). 4) adcptree.py jrCCCNNNnbenx --datatype enx Note "nb" for narrowband ping, and that the -- datatype has two dash characters 5) cd jrCCCNNNnbenx copy in a q_py.cnt file. Generally, you only need to edit the dbname and datadir for each NNN. An example q_py.cnt file is # q_py.cnt is ## comments follow hash marks; this is a comment line --yearbase 2011 --dbname jr302001nnx --datadir /local/users/pstar/cruise/data/vmadcp/jr302_os75/rawdata001 #--datafile_glob "*.LTA" --datafile_glob *.ENX --instname os75 --instclass os --datatype enx --auto --rotate_angle 0.0 --pingtype nb --ducer_depth 5 #--verbose # end of q_py.cnt # end of q_py.cnt At the start of the cruise check yearbase, dbname, os75 or os150 and datatype enx (glob ENX). Dbname should be of form jrCCCNNNPTT where P is n for narrowband, b for broadband. The instrument should be operated in narrow unless there is a good reason to choose broad. TT is “nx” for ENX; “ns” for ENS; “nr” for ENR; “lt” for LTA; “st” for STA. Standard processing is to process ENX. As far as I can tell, dbname must not exceed 11 chars. So if we use 9 for jr195NNNn, there are only two left to identify ENX, ENS, LTA, STA 6) still in directory ~data/vmadcp/jr302_os75/jr302001nbenx quick_adcp.py --cntfile q_py.cnt ("killed matlab engine" is the normal message received). This takes a minute or two per 24 hours of ENX data. Note –cntfile has two dash characters 7) To see the BT (bottom track) or WT (water track) calibration, look at the ascii output of jr302001nbenx/cal/*/*out (note that a calibration is not always achieved, for example if the ship has made no manoeuvres while the ADCP is in water tracking mode, so there may be no *out file). Note also that additional calibration information maybe saved after flags applied after gautoedit process. 8) To access data in Matlab matlab & >> m_setup >> codaspaths 9) Can manually clean up data by applying flags to suspected bad data cycles (this can be done post- cruise, ie omitted, go straight to step 10). This step can also be a useful first look at the data. Note that the uncalibrated files may show a slight bias in u and/or v which will appear as stripes that coincide with periods of on-station and steaming. This effect will disappear when you correct for the amplitude and phase error (step 12). >> cd data/vmadcp/jr302_os75/jr302001nbenx/edit >> gautoedit Clean up data. Select day and step (typically 0.1 or 0.2 days) to view, then "show now". "show now" may have to be done twice to get the surface velocity plot. "show next" to step through the file. "Del bad times" sets "bad" flags for a section of time, or for a whole profile. "rzap" allows single bins to be flagged. Note that "list to disk" must be clicked each time for the flags to be saved. Applying edits identified in gautoedit, The gautoedit process in Matlab sets flags, but doesn’t change the data. To apply the flags and recalculate a calibration, quick_adcp.py –-cntfile q_pyedit.cnt (note two dashes before cntfile) where q_pyedit.cnt contains # q_pyedit.cnt is ## comments follow hash marks; this is a comment line --yearbase 2009 --steps2rerun apply_edit:navsteps:calib:matfiles --instname os75 --auto # end of q_pyrot.cnt 10) To get data into MSTAR: >> cd /local/users/pstar/cruise/data/vmadcp/jr302_os75/jr302NNNnbenx >> mcod_01 produces output file os75_jr302NNNnnx.nc which has a collection of vars of dimensions Nx1 1xM NxM >> mcod_02 will calculate water speed and ship speed and get all the vars onto an NxM grid. This step makes data available for comparison with LADCP data. 11) Append individual 48-hour files using >>mcod_mapend This script will append individual files to create a single cruise file. It does seem to depend on the files having the same bin number and bin depths which was not the case on JR302. 12) cd /local/users/pstar/cruise/data/vmadcp/jr302_os75/jr302NNNnbenx In directory apply the final cal ONLY ONCE (adjustments are cumulative, so if this step is done twice, the cal is applied twice) when you have done the edits and applied the time-varying heading adjustment. After inspecting the cal out files, and deciding what the amplitude and phase of the calibration should be: quick_adcp.py –-cntfile q_pyrot.cnt (note two dashes before cntfile), where q_pyrot.cnt contains: # q_pyrot.cnt is ## comments follow hash marks; this is a comment line --yearbase 2011 --rotate_angle -1.0564 --rotate_amp 1.0116 --steps2rerun rotate:navsteps:calib --auto # end of q_pyrot.cnt Final calibration values used were those given by the JR302 Bottom Track data. 13) In each directory re-create Matlab files: >>cd /local/users/pstar/cruise/data/vmadcp/jr302_os75/jr302NNNnbenx >>mcod_01 >>mcod_02 Then remove and recreate the appended matlab file: >>cd /local/users/pstar/cruise/data/vmadcp/jr302_os75 >>!/bin/rm os75_jr302nnx_01.nc >>mcod_mapend 4.3 Pumped seawater: underway carbon Jennifer Clarke, Alex Griffiths, Becky Garley Eithne Tynan 4.3.1 Introduction The carbonate system is a key component of the chemical perspective of oceanography as it plays an important role in the oceans’ capacity to take up atmospheric CO2. Dissolved inorganic carbon (DIC) is present in seawater in three forms (CO2(aq), HCO3- and CO3-2) which are in equilibrium on timescale longer than a few minutes. In oceanography, the carbonate system can be determined by four parameters: DIC, dissolved carbon dioxide (pCO2), alkalinity (TA) and pH. 3 instruments were set-up to measure with high resolution from the non- toxic underway water supply along the entire cruise track. This cruise was an opportunity to test the immobilised fluorophore pCO2 sensor JC is developing for her PhD, alongside pH and DIC analysers. 4.3.2 Method pH sensor: pH is measured by adding a coloured indicator to the seawater sample and measuring the colour of the mix. The indicator is 2 mM Thymol Blue for the underway system. The spectrophotometric sensor was developed by Victoire Rerolle at NOCS sensors group (Rérolle, Floquet et al. 2012). DIC Sensor: An Apollo SciTech System has been used. The equipment is divided into two sections. The first part allows the conversion of all the inorganic species of carbon into CO2 gas by mixing it with 10% vol phosphoric acid in a closed cell. The total CO2 gas is then carried out with the help of N2 gas (99.9%) to the Li-COR, where- by infrared analysis, the amount of CO2 gas produced is analysed. The flow rate of the gas was maintained at 300ml/min. The sample volume used was 0.75 ml and a partial calibration was undertaken twice daily. The calibration consisted of flushing the instrument with air (2 x 1.5ml), followed by deionised water (1 x 1.5 ml) before being flushed with the Certified Reference Material provided by Professor A. Dickson from Scripps Oceanographic Institute (Batch 136). Seven repeats of 3 volumes (0.5, 0.75, and 1 ml) were then run with the Certified Reference Material. Furthermore, every 30 samples, the CRM was analysed 7 times (0.75 ml) to allow corrections due to the natural drift of the LICOR analyser. The CRM was changed daily, and kept in the glass bottle with a special lid and sample tube that once the CRM was opened remained on the bottle until changed. The sample tube was always sampling from the bottom of the bottle. Drift in the underway water measurements was corrected using the ratio of the measured CRM DIC (umol kg-1) to the certified value for the particular CRM. pCO2 sensor: The sensor is based on an immobilised indicator entrapped in a polymer membrane alongside a fluorescent reference compound. The indicator fluorescence altered according to the pCO2 of the seawater. The fluorescence intensity was recorded throughout the cruise and analysed based on time-domain dual-luminophore referencing (Liebsch, Klimant et al. 2000, Liebsch, Klimant et al. 2001, Stahl, Glud et al. 2006, Schroeder, Neurauter et al. 2007) using a PMT (Hamamatsu). The sensing spot was purchased from PreSens GmbH, previously attached to a PMMA disc using silicon glue provided by PreSens GmbH and soaked in artificial seawater for a month prior to use. The PMMA disc/sensing spot was then attached to the fibre optic cable head with a glue gun. Drift in the underway water measurements was corrected using the ratio of the measured CRM pCO2 (ppm) to the certified value for the particular CRM. Underway Sampling: Underway sampling for DIC and TA was undertaken every 6 hours when not at a station until the 04/07/14 where it was reduced to one sample per 8 hours. Samples were collected in 250 ml Schott Duran borosilicate glass bottles with glass stoppers that provided an air-tight seal, held shut with electrical tape wrapped around the stopper and the bottle. 2.5 ml headspace was left in each bottle and 50 µl saturated mercuric chloride solution added directly after sampling. Samples were stored in dark, insulated boxes. These will be analysed at a later date at the NOC. 4.3.3 Underway measurements The automated pCO2 and DIC systems were running continuously on the non- toxic water supply from the 06/06/2014 to 17/07/2012. Measurements were only interrupted for system performance checking, maintenance and in the ice when the non-toxic water supplied was stopped. The pH system was running from 26/06/2014 to the 17/07/2012. The data will undergo further corrections for temperature and salinity changes. The pCO2 sensor will also undergo post cruise calibration and testing and further corrections based the results of this. The consistency of the data will finally be checked thanks to comparison between the sensors, 100 underway supply DIC/Alkalinity samples and trends and correlation in other parameters such as chlorophyll, temperature, salinity and nutrients. Figure 4.3.1: CRM 136 drift for the DIC analyser Figure 4.3.2: CRM 135 drift for the DIC analyser: Figure 4.3.3: Correction factor over the whole cruise Figure 4.3.4: CRM 136 Drift for the experimental pCO2 sensor. Figure 4.3.5: CRM 135 Drift for the experimental pCO2 sensor. Figure 4.3.6: Correction factor for the experimental pCO2 sensor. Figure 4.3.7: CRM 136 Drift pH sensor References Liebsch, G., I. Klimant, B. Frank, G. Holst and O.S. Wolfbeis (2000). "Luminescence lifetime imaging of oxygen, ph and carbon dioxide distribution using optical sensors." Applied Spectroscopy 54(4): 548- 559. Liebsch, G., I. Klimant, C. Krause and O.S. Wolfbeis (2001). "Fluorescent Imaging of pH with Optical Sensors Using Time Domain Dual Lifetime Referencing." Analytical Chemistry 73(17): 4354- 4363. Rérolle, V.M.C., C.F.A. Floquet, M.C. Mowlem, R. Bellerby, D.P. Connelly and E.P. Achterberg (2012). "Seawater-pH measurements for ocean- acidification observations." Trac-Trends in Analytical Chemistry 40: 146-157. Schroeder, C., G. Neurauter and I. Klimant (2007). "Luminescent dual sensor for time-resolved imaging of pCO2 and pO2 in aquatic systems." Microchimica Acta 158: 205-218. Stahl, H., A. Glud, C. R. Schroder, I. Klimant, A. Tengberg and R. N. Glud (2006). "Time-resolved pH imaging in marine sediments with a luminescent planar optode." Limnology and Oceanography: Methods 4: 336-345. Table 4.3.1: Underway DIC/TA Sampling Log Sampler Sample ID Date GMT Notes ——————— ————————— —————————— ————— ————————————————————————————— ET UW000 16/06/2014 15:40 A lot of bubbles in underway ET UW001 16/06/2014 16:12 ET UW002 16/06/2014 22:55 AG UW003 17/06/2014 06:10 AG UW004 17/06/2014 10:20 JC UW005 17/06/2014 22:00 AG UW006 17/06/2014 05:10 At station- delayed sample BG UW007 18/06/2014 10:07 JC UW008 18/06/2014 16:02 Almost at station 53 ET UW009 18/06/2014 23:04 AG UW010 19/06/2014 04:10 BG UW011 19/06/2014 12:34 JC UW012 19/06/2014 16:03 JC UW013 20/06/2014 01:07 bubbly AG UW014 20/06/2014 05:56 At station 57- delayed sample BG UW015 20/06/2014 12:53 ET UW016 20/06/2014 21:53 AG UW017 21/06/2014 05:00 BG UW018 21/06/2014 12:19 JC UW019 21/06/2014 16:04 STN BY GREENLAND JC UW020 21/06/2014 23:07 AG UW021 22/06/2014 07:06 STN 69 BG UW022 22/06/2014 10:21 JC UW023 22/06/2014 16:09 JC UW024 22/06/2014 21:55 AG UW025 23/06/2014 04:11 BG UW026 23/06/2014 10:19 NO SAMPLING TUBE JC UW027 23/06/2014 16:56 NO SAMPLING TUBE JC UW028 23/06/2014 23:37 AG UW029 24/06/2014 05:16 BG UW030 24/06/2014 10:26 JC UW031 24/06/2014 16:11 JC UW032 24/06/2014 01:02 AG UW033 25/06/2014 04:54 BG UW034 25/06/2014 10:26 JC UW035 25/06/2014 17:52 AG UW036 26/06/2014 05:42 BG UW037 26/06/2014 10:21 JC UW038 26/06/2014 17:22 JC UW039 26/06/2014 22:04 AG UW040 27/06/2014 06:14 BG UW041 27/06/2014 10:23 JC UW042 27/06/2014 16:05 AG UW043 28/06/2014 06:00 BG UW044 28/06/2014 10:14 JC UW045 28/06/2014 23:51 AG UW046 29/06/2014 08:25 BG UW047 30/06/2014 10:17 AG UW048 01/07/2014 07:27 JC UW049 30/06/2014 17:54 JC UW050 30/06/2014 00:57 BG UW051 01/07/2014 11:20 JC UW052 01/07/2014 21:38 BG UW053 01/07/2014 11:01 JC UW054 02/07/2014 16:11 JC UW055 02/07/2014 23:27 AG UW056 03/07/2014 05:19 BG UW057 03/07/2014 10:18 JC UW058 03/07/2014 17:30 JC UW059 03/07/2014 22:04 AG UW060 04/07/2014 06:15 BG UW061 04/07/2014 11:33 JC UW062 04/07/2014 18:05 AG UW063 05/07/2014 04:10 BG UW064 05/07/2014 09:00 JC UW065 05/07/2014 19:13 AG UW066 06/07/2014 03:23 BG UW067 06/07/2014 09:29 JC UW068 06/07/2014 17:51 AG UW069 07/07/2014 03:42 BG UW070 07/07/2014 10:27 JC UW071 07/07/2014 18:49 AG UW072 08/07/2014 01:31 BG UW073 08/07/2014 09:20 AG UW074 09/07/2014 01:30 BG UW075 09/07/2014 09:25 JC UW076 09/07/2014 18:18 AG UW077 10/07/2014 02:03 BG UW078 10/07/2014 11:11 CF UW079 10/07/2014 19:38 AG UW080 11/07/2014 02:22 BG UW081 11/07/2014 09:11 JC UW082 11/07/2014 17:22 AG UW083 12/07/2014 02:28 BG UW084 12/07/2014 10:08 JC UW085 12/07/2014 17:50 AG UW086 13/07/2014 05:36 BG UW087 13/07/2014 10:04 JC UW088 13/07/2014 17:03 AG UW089 14/07/2014 01:21 BG UW090 14/07/2014 08:33 JC UW091 14/07/2014 17:59 AG UW092 15/07/2014 02:02 BG UW093 15/07/2014 09:08 JC UW094 15/07/2014 16:36 AG UW095 16/07/2014 01:14 BG UW096 16/07/2014 08:11 JC UW097 16/07/2014 17:23 AG UW098 17/07/2014 02:35 BG UW099 17/07/2014 08:23 JC UW100 17/07/2014 16:03 5. AUTONOMOUS PLATFORMS 5.1 Floats Eight Met Office Argo floats were deployed during the cruise. All floats were checked for functionality before being deployed; they were connected to a laptop and a series of pre-deployment checks carried out. After disconnection from the laptop they were reset and activated using a magnet. Deployment was from the stern starboard quarter with a rope, as the ship steamed slowly forwards. Table 5.1: Float deployments Float Reset time Deployment time Deployment Deployment Associated CTD ID (year day/UTC) latitude longitude station number ————— —————————— ——————————————— —————————— ——————————— —————————————— 7011 186/0158 186/0350 57.95295 -27.00062 jr302/138 5 July 2014 57 57.18 N 27 0.04 W 7012 187/2242 187/2352 57.90795 -20.68557 jr302/148 6 July 2014 57 54.48 N 20 41.13 W 7013 191/0016 191/0144 59.40160 -18.43511 jr302/177 10 July 2014 59 24.10 N 18 26.11 W 7014 191/0907 191/1108 59.80868 -19.50388 jr302/180 10 July 2014 59 48.52 N 19 30.23 W 6608 191/1728 191/1855 60.24949 -19.99944 10 July 2014 60 14.97 N 19 59.97 W jr302/182 6611 193/1836 193/2005 61.49963 -20.00134 12 July 2014 61 29.98 N 20 0.08 W jr302/195 6610 194/0837 194/0955 61.00055 -20.00137 13 July 2014 61 0.03 N 20 0.08 W jr302/198 6609 196/1720 196/1852 57.29858 -10.38108 15 July 2014 57 17.91 N 10 22.86 W jr302/211 5.2 Seaglider Stefan Gary The iRobot Seaglider Bellatrix (SG532) was recovered on the morning of 13 July. Bellatrix had been waiting at 61N, 20W, which coincided approximately with stations 185 and 198, for several days for an appropriate weather window for recovery. On 13 July, conditions were ideal: good visibility and low swell. As the JCR approached the rendezvous point, Bellatrix was commanded to execute successively shallower dives and the positions of each dive were monitored in real time via an SSH link to the glider's base station at the Scottish Association for Marine Science (SAMS). At 0700GMT, the pilot commanded Bellatrix to enter recovery mode. She was sighted about 10 minutes later and the ship pulled alongside at 0736GMT. After several attempts, at 0748GMT, a line was secured to Bellatrix's rudder, the lift point for a Seaglider, using a bowline-in-a-bight taped on the end of an approximately 10 m pole. This process was challenging since Bellatrix's rudder was almost continuously submerged and the line sunk very slowly. After the recovery, it was discovered that the glider was floating low because the pilot ommitted to command Bellatrix to pump to maximum buoyancy. Future Seaglider recoveries should be easier if this command is executed. The ~10 m pole, worked by a minimum of two people, was of sufficient length to lasso the glider despite the height of the freeboard. With the glider lassoed, she was then lifted aboard with the gantry at 0750GMT, placed in her cradle, and the wings, rudder, and antenna where disassembled. Standard post-recovery internal pressure (~8.5 PSIA) and internal humidity (~14.00RH) checks were carried out and these values matched the safe operating ranges maintained by the glider for the duration of her mission. Bellatrix was then commanded to enter travel mode, turned off, and then rinsed with freshwater before being packed into the shipping crate. The Argos tag on Bellatrix's antenna was also switched into standby mode. Bellatrix was deployed west of the Isle of Coll on the Scottish Shelf on April 30th and navigated to the rendezvous point over the course of two months (Figure 5.2.1). The raw data collected during this mission were posted in real time to http://velocity.sams.ac.uk/gliders/sg532. Bellatrix operated with remarkably few errors or other issues for her whole mission. Recovering a glider from a large ship is a challenging task and the crew of the JCR did an outstanding job supporting the recovery; everyone was very keen to sort out logistical details, open to hearing about the special requirements of gliders, and enthusiastic. Figure 5.2.1: Seaglider Bellatrix (SG532) track from 30th April, 2014 to 13th July, 2014 (red line) compared to the Extended Ellet Line (black line). Bathymetry is contoured at 500 m intervals (black lines) and 100 m intervals for depths less than 500 m (gray lines). 6. OUTREACH N.P. Holliday A daily cruise blog was written during JR302 (ukosnap.wordpress.com), with the specific ambition of attracting readers who are not marine scientists. The aim was to provide simplified explanations of our science and of life onboard the ship and to illustrate this with nice photographs. Posts were mainly written by Penny Holliday and featured contributions from scientists and ship's staff. The blog was advertised through Facebook and Twitter (@ukosnap) and word of mouth (family and friends). The readership grew steadily throughout the cruise, peaking at over 1200 views on one day, and reaching a total of over 25,000 views by the end of the cruise. Video footage was collected throughout the cruise by Penny Holliday, Sinhue Torres Valdes and Stefan Gary. We filmed people working, the scenery, and the CTD underwater, and interviewed the PS. We also made some time lapse movies. Some were put on the UKOSNAP youtube channel during the cruise, and more will be added after the cruise and advertised through our websites, twitter and facebook. The clips will be used for outreach activities by NOC, PML and SAMS for the RAGNARRoC and OSNAP projects. CCHDO Data Processing Notes • File Submission Andrew Barna ar07_74JC20140606_ct1.zip (download) #43b94 Date: 2015-06-17 Current Status: merged Notes Test submission of an already existing file • File Merge CCHDO Staff ar07_74JC20140606_ct1.zip (download) #43b94 Date: 2015-05-28 Current Status: merged • CTD online, exchange and netcdf formats SEE Date: 2015-05-28 Data Type: CTD Action: Website Update Note: AR07 2014 74JC20140606 processing - CTD online - CTDPRS,CTDTMP,CTDSAL,CTDOXY 2015-05-28 SEE Submission filename submitted by date id --------------------------------- ------------ ---------- ---- ar07_74JC20140606_ct1.zip Brian King 2014-07-22 4490 Changes ar07_74JC20140606_ct1.zip - for file ar07_74JC20140606_00171_00001_ct1.csv, changed CTDOXY flags from 2 to 4 between 361 and 433 dbar. :Updated parameters: CTDPRS,CTDPRS_FLAG_W,CTDTMP,CTDTMP_FLAG_W,CTDSAL,CTDSAL_FLAG_W,CTDTMP,C TDTMP_FLAG_W ar07_74JC20140606_ct1.zip opened in JOA with no apparent problems. ar07_74JC20140606_nc_ctd.zip opened in JOA and ODV with no apparent problems. • File Submission Brian King ar07_74JC20140606_ct1.zip (download) #43b94 Date: 2014-09-08 Current Status: merged Notes CTD data • to go online Brian King Date: 2014-09-08 Data Type: CTD Action: Submitted Note: CTD data are final we believe. Bottle data still need some work. The Bottle data file is an 'end of cruise' file. CFCs are incomplete. Samples were analysed on board but analyses not yet received. Carbon data have a number of stored samples for analysis ashore, signified by absent analysis value and flag = 1. Bottle oxygen have some unexplained station offsets making all bottle oxygen data from those stations questionable. However the data are not yet flagged as 3. • Available under 'Files as received' CCHDO Staff Date: 2014-09-08 Data Type: CTD Action: Website Update Note: The following files are now available online under 'Files as received', unprocessed by the CCHDO. ar07_74JC20140606_ct1.zip • File Submission Brian King ar07_74JC20140606_ct1.zip (download) #43b94 Date: 2014-07-22 Current Status: merged Notes Expocode: 74JC20140606 Ship: James Clark Ross Woce Line: AR07W/OSNAP-W/AR07E/OSNAP-E/AR28 Note: CTD data are final we believe. Bottle data still need some work. The Bottle data file is an 'end of cruise' file. CFCs are incomplete. Samples were analysed on board but analyses not yet received. Carbon data have a number of stored samples for analysis ashore, signified by absent analysis value and flag = 1. Bottle oxygen have some unexplained station offsets making all bottle oxygen data from those stations questionable. However the data are not yet flagged as 3. [...] the CTD data are GO-SHIP and can be considered as fully public. We believe they are final. I would like to get confirmation of the preferred line designators eg AR07W ONSAP-W AR07E OSNAP-E AR28 so that we can start using them now and avoid switching in the future. Bottle data contain a variety of data issues remaining to be resolved, so they are not suitable for public dissemination yet. But the bottle file can be used to compile a list of parameters measured.