CRUISE REPORT: SR01b (Updated DEC 2016) Highlights Cruise Summary Information Section Designation SR01b alias JR15003 Expedition designation (ExpoCodes) 74JC20151217 Chief Scientists Yvonne Firing / NOC Dates 2015 DEC 17 - 2016 JAN 13 Ship RRS James Clarke Ross Ports of call Port Stanley, Falkland Islands -South Powell Island - Signy Island - Coronation Island - Rothera Research Station - Verndasky Research Base - Port Stanley 54° 40' S Geographic Boundaries 70° 10' 14.8" W 54° 35' 16"W 67° 48' 13" S Stations 28 Floats and drifters deployed 4 SOCCOM floats deployed Moorings deployed or recovered 0 Contact Information: Yvonne Firing National Oceanography Center, Southampton Tel: 02380 599669 • email: yvonne.firing@noc.ac.uk National Oceanography Centre NATURAL ENVIRONMENT RESEARCH COUNCIL National Oceanography Centre Cruise Report No. 38 RRS James Clark Ross Cruise JR15003 17 DEC – 13 JAN 2016 Hydrographic measurements on GO-SHIP line SR1b and investigations of circulation and isotope cycles in coastal West Antarctica Principal Scientist Y Firing 2016 National Oceanography Centre, Southampton University of Southampton Waterfront Campus European Way Southampton Hants SO14 3ZH UK Tel: +44 (0)23 8059 9669 Email: yvonne.firing@noc.ac.uk © National Oceanography Centre, 2016 DOCUMENT DATA SHEET AUTHOR PUBLICATION FIRING, Y et al DATE 2016 TITLE RRS James Clark Ross Cruise JR15003, 17 Dec 2015 - 13 Jan 2016. Hydrographic measurements on GO-SHIP line SR1b and investigations of circulation and isotope cycles in coastal West Antarctica. REFERENCE Southampton, UK: National Oceanography Centre, Southampton, 41pp. (National Oceanography Centre Cruise Report, No. 38) ABSTRACT This cruise comprised work contributing to five projects. The twenty-first complete occupation of the Drake Passage GO-SHIP section SR1b obtained full-depth temperature, salinity, and lowered ADCP velocity profiles at 28 stations, along with underway measurements, with the objectives of investigating and monitoring interannual variability and trends in Antarctic Circumpolar Current structure and property transports and Southern Ocean water mass properties. Turnarounds of bottom pressure recorder (BPR) moorings contributed to the long time series of bottom pressure in Drake Passage. Biogeochemically-equipped Argo floats were deployed as part of the Southern Ocean Carbon and Climate Observations and Modelling (SOCCOM) project to increase climate-quality observations in the Southern Ocean. Gliders were deployed over the Western Antarctic Peninsula continental shelf to measure properties and circulation with the aim of understanding flow and mixing of warm waters onto the shelf. Hydrographic profiles and water column and sediment samples taken over the continental shelf will be used to investigate stable isotope nutrient cycling processes. 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 1 Personnel 6 2 Itinerary and Cruise Track 7 3 Objectives 7 4 Narrative 8 5 Slocum glider deployments 10 5.1 Glider 438 11 5.2 Glider 331 11 6 CGS: Understanding the cycling of stable isotopes in coastal Antarctic waters 12 6.1 Objectives 12 6.2 Project report 12 6.3 Comments and recommendations 13 7 Continuous Ocean Monitoring Methods: Drake Passage 14 8 Hydrographic Measurements 14 8.1 CTD Systems Operation 15 8.1.1 CTD operation and processing 15 8.1.2 Data Processing 16 8.2 Water Sample Analysis 17 8.3 Data calibration 19 8.4 Lowered Acoustic Doppler Current Profiler (LADCP) 19 8.4.1 Instrument setup and performance 19 8.4.2 Data processing 20 8.5 References 22 9 SOCCOM (Southern Ocean Carbon and Climate Observations and Modeling) float deployments and CTD stations 23 9.1 Float Deployments 23 9.2 CTD/Rosette Sampling 24 9.3 Dissolved Oxygen 24 9.4 Sampling and Data Processing 24 9.5 Equipment and Techniques 24 9.6 Volumetric Calibration 25 9.7 Standards 25 9.8 pH/Alkalinity 25 9.9 Nutrients 25 9.10 Salinity 25 9.11 HPLC and POC 25 9.12 References 26 10 Underway Data Collection and Processing 26 10.1 Computing and SCS data processing 26 10.1.1 Configuration of linux workstation ’fola’ 26 10.1.2 SCS data streams 27 10.1.3 Access to SCS data 27 10.1.4 The mscs source directory 29 10.2 Underway surface water sampling 29 10.2.1 Underway surface thermosalinograph 29 10.3 Surface water sampling for Nd isotope analysis 30 10.4 Daily processing of SCS streams 30 10.4.1 Navigation 30 10.4.2 Surface meteorological sampling (SURFMET) 31 10.4.3 Bathymetry 31 10.4.4 EA600 32 10.4.5 EM122 32 10.4.6 Chernikeef EM log 33 10.5 Vessel Mounted ADCP 33 10.5.1 Real-time data acquisition and VMDAS files 33 10.5.2 Settings 34 11 Instrumentation, extracted from AME Report 35 12 Acknowledgments 36 CCHDO Data Processing Notes 37 List of Figures 1 JR15003 cruise track with glider deployment sites (red triangles), CGS CTD sites (filled green circles), CGS underway surface Nd sampling (open green circles), BPRs (gray stars), SR1b CTD sites (magenta squares), and float deployment sites (black square outlines). 8 2 Calibrated temperature on SR1b, with bottle firings (corresponding to SBE35 samples) shown by black circles and float deployment stations by squares. 22 3 Calibrated salinity on SR1b, with bottle salinity samples shown by black circles and float deployment stations by squares. 22 4 Calibrated dissolved oxygen on SR1b, with bottle oxygen samples shown by black circles and float deployment stations by squares. 22 5 Profiles of zonal (top) and meridional (bottom) velocity from LADCP at each station in Drake Passage, offset to the latitude of that station, with dashed zero lines. Right hand panels show northern profiles including the Subantarctic Front jet, with a common zero line. 22 List of Tables 1 CGS CTD and sediment core sites. 12 2 CTD stations times and positions, with number of bottle salinity and oxygen samples obtained for calibrating CTD sensors. 14 3 LADCP deployment commands, contained in JR15003 ladcp.cmd. 20 4 SOCCOM floats with deployment times and positions. I = ice enabled; O = oxygen sensor; N = nitrate sensor; F = fluorometer (WetLabs FLBB); p = pH sensor 23 5 Times (from log sheet) and locations (from ship track) of surface water samples for Nd isotope analysis 30 6 Lab instruments used 35 7 Acoustic instruments used 35 8 Oceanlogger 35 9 CTD 35 10 AME unsupported instruments logged 36 1 PERSONNEL Scientific Personnel Yvonne Firing (Principal Scientist) NOC Alexander Brearley BAS Sian Henley U Edinburgh David Byrne NOC, U Liverpool Lucie Cassarino U Bristol Tianyu Chen U Bristol Casimir de Lavergne LOCEAN Damien Desbruyeres NOC Jennifer Mecking U Southampton Daniel Schuller Scripps Institution of Oceanography Technical Personnel Johnny Edmonston BAS IT Paul Morgan BAS AME Ship’s Personnel Graham Chapman Master Simon Wallace Chief Officer Christopher Hipsey 2nd officer Georgina Delph 3rd Officer Harry Taylor 3rd Officer Charles Waddicor ETO Comms Luke Parnell Chief Engineer Edel Trearty 2nd Engineer Stephen Gardiner 3rd Engineer Steven Eadie 4th Engineer Simon Wright Deck Engineer Julian Klepacki ETO James Gibson Purser Tim Osborne Doctor George Stewart Bosun/Sci Ops Clifford Mullaney Bosun John O’Duffy Bosuns Mate Kevin Cambell AB Colin Leslie AB Lasse Pedersen AB Martyn Dyer AB Stephen Pictor Motorman Kristian Bates Motorman Padraig Molloy Chief Cook Brian Robertson 2nd Cook Derek Lee Senior Steward James Newall Steward Thomas Patterson Steward Roger Route Steward 2 ITINERARY AND CRUISE TRACK JR15003 sailed from Port Stanley, Falkland Islands on 17 December 2015, called at three of the South Orkney Islands December 20-22, at Rothera 28 December - 2 January, 2016, at Vernadsky on 4 January, and returned to Port Stanley on 13 January 2016. Science operations were conducted on both the southbound leg along the western Antarctic Peninsula between 24 December and 28 December, and the northbound leg in Drake Passage between 6 January and 11 January, along with standard underway sampling during much of the time at sea. The cruise track and sites of science work are shown in Figure 2. 3 OBJECTIVES RRS James Clark Ross cruise JR15003 included work contributing to five projects: • What causes the influx and mixing of warm waters on polar ocean shelves? A Brearley, M Meredith, and M Inall, BAS To deploy gliders to measure water mass properties and circulation on the West Antarctic Peninsula continental shelf. • Understanding the cycling of stable isotopes in coastal Antarctic waters K Hendry and L Cassarino, U Bristol; S Henley, U Edinburgh; Y Firing, NOC; R Mills and T Stichel, U Southampton; M Meredith, BAS To sample the stable isotope composition of nitrogen, silicon, and neodymium through the water column and in the upper sediments in order to understand the key biological and non-biological processes setting these profiles in different parts of the western Antarctic Peninsula continental shelf. • Continuous Ocean Monitoring Methods: Drake Passage S Mack, NOC To maintain the long time-series of transport through Drake Passage by recovering and redeploying two bottom pressure recorders (BPRs), one on either side of the passage. • Hydrographic measurements in Drake Passage Y Firing, NOC To make high-quality repeat hydrographic measurements on GO-SHIP line SR1b, continuing a near-annual time series begun in 1993, as part of the Drake Passage repeat hydrography National Capability programme designed to monitor Southern Ocean watermasses and Antarctic Circumpo- lar Current volume and property transport; to obtain complementary station and underway currents and underway meteorology. • Southern Ocean Carbon and Climate Observations and Measurements (SOCCOM) L Talley and A Dickson, Scripps Institution of Oceanography; S Riser, U Washington; K Johnson, MBARI; E Boss, U Maine; R Feely, NOAA PMEL; L Juranek, Oregon State U; J Sarmiento and R Key, Princeton U To increase the sampling of physical and biogeochemical parameters in the Southern Ocean by deploying four biogeochem-equipped Apex floats and acquiring climate-quality calibration measurements. The glider work was funded by NERC. The BPR and hydrography components are part of National Capability projects funded by NERC. The isotope cycling experiment was funded by NERC through the BAS Collaborative Gearing Scheme (CGS, now Collaborative Antarctic Science Scheme). SOCCOM is funded by the USA National Science Foundation and float deployment was performed opportunistically alongside the NERC-funded hydrography. Figure 1: JR15003 cruise track with glider deployment sites (red triangles), CGS CTD sites (filled green circles), CGS underway surface Nd sampling (open green circles), BPRs (gray stars), SR1b CTD sites (magenta squares), and float deployment sites (black square outlines). 4 NARRATIVE Yvonne Firing JR15003 sailed from Port Stanley, Falkland Islands the evening of 17 December 2015 in calm conditions, headed for the South Orkney Islands. Underway data logging, including VMADCP and tsg, commenced on 18 December. It took a bit of trial and error to find a useable configuration of the acoustic sampling run through the k-sync program, as the previous year’s configuration did not seem to work. The ship called at South Powell Island on 20th December, dropping off a field party of three, and allowing some of the scientists and fids to visit the island for a few hours. At Signy the following day four fids disembarked, and most science and passengers visited the station, where we were kindly provided with a tour of the area. Finding and setting up a camp at Coronation Island on 22 December proved challenging due to ice conditions (which slowed operations around the South Orkneys in general), but in the end the two scientists and their gear were landed and settled in. Late on the 22nd we were again underway headed for the first planned glider deployment site off Anvers Island. Some wind, sea, and swell were encountered on the 24th, and the VMADCP was turned off in favour of obtaining swath bathymetry data along a new track. Due to ice conditions the JCR took a course outside Anvers Island, and we decided to move the first glider deployment location and CTD/sediment core site from Palmer Deep to off the western tip of Anvers Island. The first glider deployment, in the early hours of 25 December, went smoothly, with a successful test dive. We did a CTD cast including water sampling for nutrients and trace metals adjacent to the glider deployment site, followed by a sediment core. However, as we were continuing southward several hours later, the glider data indicated that it had leaked. We therefore returned to recover it, and deployed the second glider at that site. A forensic examination of the first glider did not reveal a reason for the leak. Up-to-date satellite imagery was limited due to cloud cover but appeared to indicate continued heavy ice over the continental shelf; therefore we abandoned plans to deploy a second glider and CTD with nutrient sampling between Anvers and Adelaide and attempted to go around the ice until closer to Adelaide Island. Progress toward Rothera was slow through 3/10 to 8/10 ice, exacerbated by a problem with one of the two main engines. Our next planned CTD site was completely ice-covered but we found open water just 6 kilometers to the southeast, and were able to conduct a CTD cast and sediment core at a comparable depth there on 27th December. As the first glider hull appeared to be in good shape and the electronics undamaged, o-rings were changed and it was decided to deploy it in Ryder Bay for test dives, with the hope that it could then be sent out onto the shelf to complete some of the original sampling plan throughout the summer. Upon our arrival in Ryder Bay early on the morning of the 28th, we found that our last southbound CTD site, the RaTS site, was also too icy, and therefore moved to the backup RaTS site a few km away to redeploy the first glider and do a CTD cast and sediment core. On the first two core attempts a small rock was stuck in the corer jaws, so the sediment leaked out; however the third attempt recovered enough mud to work with. The JCR was alongside at Rothera from 28th December to 2nd January, 2016, performing cargo resupply for the station. The NOCL technicians also serviced the Rothera tide gauge during this call. Due to ice damage to the wharf the fore and aft decks had to be offloaded separately. The station personnel generously organised crevassing and skiing expeditions for the ship party and welcomed us to their New Year’s Eve celebrations as well as dinner exchanges with outgoing and incoming winterers. During the Rothera call the glider in Ryder Bay became stuck under ice, but otherwise at first appeared to be functioning as designed. On the 1st, however, the leak detect flagged again. The glider was therefore recovered by the JCR upon departure from Rothera on the morning of 2nd January. We then headed offshore, emerging from the ice late on the 3rd, and coming into Verndasky the morning of the 4th. There the NOCL technicians serviced the tide gauge and the science party, officers, and crew were treated to the station hospitality. We departed Vernadsky on the evening of the 4th and passed Elephant Island early on the 6th. The SR1b CTD stations were begun at 0600 on the 6th. CTD casts over the slope were only conducted to 30 m above the bottom due to fluctuating echosounder depth readings. The SACCF appears to have been relatively far south, as the influence of CDW was visible early on, before SR1b site 6 (cast 009). At this point it was discovered that the LADCP beam 2 had been bad (unnoticed earlier, as reasonable solutions were still obtained from 3 beams). The LADCP was switched for the spare unit before cast 007. The south slope BPR at first did not respond to acoustic transmissions, but did respond to the ship’s transponder, implying an issue with the NOCL deck unit. Following this the release and recovery, and deployment of the replacement, went smoothly. The CTD power cable between the rosette swivel and the CTD had to be replaced as it was smashed (broken connector and bent pin) just below the swivel, apparently due to hitting the insufficiently-opened roller door over the water sampling bay. The data do not appear to have been affected. Floats were deployed following CTD casts 009, 012, 016, and 020 (SR1b sites 6, 9, 13, and 17). In addition to the calibration water samples taken at the four float deployment stations, oxygen samples were taken at 11 additional sites (casts 004, 006, 008, 010, 011, 015, 017, 019, 021, 028 and 029) for calibration of the CTD oxygen sensor. Following some misfired bottles on early casts we decided to rinse and clean the bottle carousel more frequently. The CTD secondary temperature and conductivity sensors on cast 016 looked bad, but the problem was solved by flushing with a detergent solution. In mid-passage the passage the weather worsened, with forecasts predicting rougher conditions to- ward the end of our science time. We had a weather delay of approximately 4 hours on the 8th, moving on after the 10th SR1b station (13th cast of the cruise) to a station halfway between the originally-planned 11th and 12th SR1b stations, and then to the originally-planned 13th station (thus, a spacing of 2 rather than 3 stations over 70 km). Following this, with the forecast still predicting more heavy weather, station spacing was increased from the nominal 20 nm to 25 nm to make progress across the passage. We stopped work and hove to for weather mid-day on the 10th, stopping the underway sampling at approximately 2000Z as we approached the Argentine EEZ. We resumed at 0900Z on the 11th with a CTD cast in 2200 m, still in some wind and swell. As the conditions were then improved enough to consider BPR operations, we first visited the BPR at 2000 m to check its communications and battery levels, which were good. We then moved on to the 1000 m BPR, which was successfully recovered and replaced. A nearby BPR which failed to release in 2013 proved to be still communicating, but did not release. CTD stations were resumed starting at 1700 m, and finished at 2100 on 11 January. The swell picked up for our steam over Burdwood Bank, supplying additional liveliness to the end-of- cruise festivities, but by the following day wind and seas had abated enough for the ship to take care of unwinding and respooling a winch cable from a previous cruise. We returned to Port Stanley the morning of the 13th. 5 SLOCUM GLIDER DEPLOYMENTS Alexander Brearley, Alvaro Lorenzo Lopez Two Slocum gliders from the National Marine Equipment Pool were deployed on the southbound leg of JR15003, as part of the project “What causes the influx and mixing of warm waters on polar ocean shelves?”, led by Alexander Brearley. The first glider, serial number 438 and named Frazil, incorporated pumped Seabird CTD, WetLabs Ecopuck, Satlantic PAR sensor, Aanderaa oxygen optode and thruster. The second, serial number 331 and named Coprolite, incorporated unpumped Seabird CTD, WetLabs Ecopuck and oxygen optode. Both gliders had previously been ballasted in Oban during the BAS trials week on 22 to 26 June 2015. Standard functional checkouts were completed on the transit south from Stanley at the start of the cruise. 5.1 Glider 438 It was initially planned to deploy 438 in Palmer Deep, and 331 just to the northwest of Adelaide Island. However, inspection of in situ ice conditions and SAR satellite images of the Peninsula revealed extensive sea ice close to the planned deployment sites. The first deployment site was thus moved to west of Anvers Island and Glider 438 was deployed at 64°30.478S, 64°50.868W at 0430Z on 25 December 2015. The ice coping software was loaded onto the gliders using loadmission ice.mi, and the mission filename for this season is shelf.mi. A concurrent CTD was completed at the site. Unfortunately, at 0956Z, the glider aborted for a leak in the aft compartment. The JCR scrambled and recovered the glider at 1454Z on 25 December 2015. Subsequent inspection of the aft compartment revealed a trickle of salt crystals from close to the rear leak detector into the rear hull, and a significant pool of water sitting under the Teflon protecting the steatite battery. No evidence of O-ring damage was apparent, but we removed and changed out all the aft compartment O-rings as a precaution. As we had not definitively determined the root cause of the leak, we decided to redeploy in Ryder Bay where small-boat support was available from Rothera. The glider was redeployed at 67034.476S, 68008.392W on 28 December 2015 at 0910Z (immediately before the final CTD site). We chose two closely spaced waypoints in Ryder Bay. Unfortunately, after two dives, the glider became stuck under a layer of sea ice, and no communications were received until 0541Z on 29th December (abort for MS ABORT NO TICKLE ICE). By this time, the glider had drifted significantly to a point between Leonie and Kirsty Island. Efforts to get the glider back into Ryder Bay were inhibited by further glider aborts for the thruster and digifin (presumably because both became stuck in ice). The glider finally returned to deep water around 2000Z on the 29th December, but aborted again for a leak in the aft compartment at round 2130Z at 277 m depth. An unsuccessful attempt to recover the glider was made early on the 30th using the Rothera rib Nimrod, but the site could not be reached because of heavy sea ice. Leaving the glider on a surface callback script, we tracked the glider as it drifted quickly southwards over the next three days (on lastgasp.mi), ultimately reaching a position to the south of Adelaide Island. By this stage, we were concerned that the glider was approaching a line of heavy sea ice, beyond which it may have become unrecoverable. We thus programmed the glider to do shallow dives (initially to 10 m, later to 100 m, with 3 yos) to prevent further southward drift. The glider was collected by the JCR after its departure from Rothera after relief, at around 1345Z on January 2nd, at a position of 67°59.567S, 68°23.449W. The source of the leak has still not been identified, so we will conduct a closer analysis once back in the UK. 5.2 Glider 331 It had initially been planned to deploy 331 to the northwest of Adelaide Island. However, upon the failure of 438, it was deployed close to the original deployment position of 438, at 64°28.700S, 64°50.787W at 1600Z. No significant issues were encountered with 331 during the duration of the cruise, other than the altimeter terminating dives slightly early (⇠100-200 m from the bottom). We resolved this by setting: sensor: u alt reqd good in a row(nodim) 5 in the yo11.ma file. Piloting logs Piloting notes for each glider were maintained on the Cambridge dockserver, Under /home/localuser/438 pilot log and /home/localuser/331 pilot log. 6 CGS: Understanding the cycling of stable isotopes in coastal Antarctic waters Sian Henley, Lucie Cassarino, Tianyu Chen, Yvonne Firing 6.1 Objectives The aim of this CGS project was to examine the biogeochemical cycling of silicon (Si) and nitrogen (N) in surface waters, throughout the water column and in sediments along the west Antarctic Peninsula. Stable isotopic signatures of silicon and nitrogen in each of the different biogeochemical system components will be used to understand biological production, remineralisation and nutrient recycling processes occurring during sinking and sedimentation of organic matter. Neodymium (Nd) isotopes will be used to trace relevant water masses and local freshwater inputs, with relevance for trace metal fluxes to the water column. These two work packages combined will inform on processes influencing biological drawdown of carbon in this climatically and environmentally-sensitive region, as well as providing insight into the past. 6.2 Project report Water column sampling and sediment box-coring were conducted at three sites along the Antarctic Peninsula, listed in Table 1 and shown in Figure 2. Table 1: CGS CTD and sediment core sites. Station Latitude Longitude Depth (EM122) ------- ----------- ----------- ------------- 001 64 30.5391S 64 50.8731W 594 m 002 66 50.9766S 70 09.9624W 565 m 003 67 34.9440S 68 08.7666W 388 m Water column samples were taken in full depth profiles and were processed in the main laboratory. Oxygen isotope samples were taken first, followed by nutrients, particulates, Nd isotopes and salts. Oxygen isotope samples were taken into glass bottles, which were crimp-sealed immediately and stored in the dark at +4C. Nutrient samples were filtered through 0.2 um supor membrane filters. Nutrient and nitrate isotope samples were snap- frozen at -80C then stored at -20C. Silicic acid samples were stored in the dark at +4C. Particulate organic carbon (POC) and nitrogen (PON) samples were obtained by filtration using GF/F filters and a custom-built overpressure system. Samples were snap-frozen at -80C and stored at -20C. This large volume filtration was also conducted using polycarbonate filters; filtrate was acidified with HCl (1mL/L) and stored in the dark for Nd isotope analysis, whilst filters were stored in the dark at +4C for biogenic silica analysis. Salts samples to calibrate the shipboard CTD were taken into glass bottles, brought to room temperature at least overnight and analysed onboard using the ships Guildline Autosal instrument (described in Section 8.2). Upper sediment samples were collected at each CTD station by box-coring. Interface waters were collected immediately, then sub-cores were taken from the box core for pore fluid extraction and core sectioning. Pore fluids were extracted using rhizon syringe filters every 2 cm and were stored for analysis of nutrient concentrations, Si isotopes and N isotopes as for sea water samples. Separate cores were sectioned in 2 cm intervals, and stored at +4C, for analysis of sedimentary Si and N isotopes. All samples have been processed and shipped back to the UK for analysis. As such, there are no preliminary results to be included in this cruise report. 6.3 Comments and recommendations CGS-109 was completed successfully as part of cruise JR15003. Ice conditions dictated that all three proposed sites had to be moved, but this was done in consultation with the Captain, and without compromising the scientific objectives. A fourth water column sampling station was lost due to logistic constraints, but this again did not compromise the objectives set out in the bid. All sampling and processing was completed successfully within the time constraints of the cruise. Large volume filtration of water column samples was time-consuming and could be optimised for future work of this type. Nutrient filtrations were complete within one hour of sampling and POC filtrations were complete within four hours. Samples were kept in the dark at +4 C to limit biological activity and upper ocean samples were processed first. For Station 001, Nd and biogenic silica filtrations were completed within 12 hours of sampling. For Stations 002 and 003, samples were kept in the dark at +4 C and were processed within 36 hours of sampling. For future cruises where samples for both biogenic silica and Nd are required, a recommendation would be that these filtrations should not be combined. Nd samples should be filtered through large-diameter filters, due to their large volume requirement, whilst biogenic silica samples should be filtered using 25 mm polycarbonate filters. Box cores were taken successfully at all three stations. At Station 003, three attempts were necessary to take a successful box core, due to rocks preventing full closure on the first two attempts. More detailed echo- sounding using the TOPAS system onboard JCR might be used in future to prevent this occurrence, although the presence of small dropstones is an inevitable possibility in the nearshore Antarctic. All samples are expected to be analysed and the data available 24 months from sampling, in agreement with NERC protocols. 7 CONTINUOUS OCEAN MONITORING METHODS: DRAKE PASSAGE Jeff Pugh and Emlyn Jones A BPR was recovered and a new one deployed at both the south and north sides of the passage. Communications with the BPR at 2000 m on the northern slope were successful. Details are available in NOC cruise report No. 58, “Sea Level and Bottom Pressure Measurements in Drake Passage and the Southern Ocean”. 8 HYDROGRAPHIC MEASUREMENTS Yvonne Firing The 31 CTD casts, including 3 contributing to the CGS project and 28 on SR1b, are summarised in Table 2. Table 2: CTD stations times and positions, with number of bottle salinity and oxygen samples obtained for calibrating CTD sensors. Bottom CTD time water max N N stn date (UTC) latitude longitude depth press salt oxy --- ---------- ------ -------- --------- ----- ----- ----- ---- 1 2015/12/25 06:12 -64.5090 -64.8479 589 587 6 0 2 2015/12/27 06:12 -66.8497 -70.1708 566 562 6 0 3 2015/12/28 10:12 -67.8036 -68.8146 387 383 6 0 4 2016/01/06 09:01 -61.0500 -54.5878 361 356 6 6 5 2016/01/06 11:01 -60.9811 -54.6299 582 580 6 0 6 2016/01/06 13:01 -60.8502 -54.7102 974 975 8 6 7 2016/01/06 18:01 -60.8332 -54.7217 1735 1731 10 0 8 2016/01/06 20:01 -60.7995 -54.7424 2649 2664 8 6 9 2016/01/07 01:01 -60.6666 -54.8248 3094 3136 24 24 10 2016/01/07 06:01 -60.3333 -55.0313 3437 3489 12 6 11 2016/01/07 11:01 -60.0112 -55.2300 3496 3548 11 7 12 2016/01/07 16:01 -59.6667 -55.4444 3674 3732 23 24 13 2016/01/07 20:01 -59.3332 -55.6512 3755 3815 12 0 14 2016/01/08 01:01 -58.9998 -55.8581 3776 3833 12 0 15 2016/01/08 10:01 -58.5246 -56.1543 3787 3845 10 6 16 2016/01/08 16:01 -58.0500 -56.4466 3970 4035 23 23 17 2016/01/08 21:01 -57.6537 -56.6892 3467 3518 12 6 18 2016/01/09 02:01 -57.2588 -56.9334 3949 4013 12 0 19 2016/01/09 08:01 -56.8639 -57.1778 3014 3053 12 6 20 2016/01/09 13:01 -56.4685 -57.4128 3826 3886 24 24 21 2016/01/09 18:01 -56.0756 -57.6656 3847 3908 13 6 22 2016/01/10 00:01 -55.6817 -57.9093 4524 4604 11 0 23 2016/01/10 04:01 -55.5167 -57.9829 4211 4279 12 0 24 2016/01/10 09:01 -55.2154 -57.9622 3928 3985 12 0 25 2016/01/10 12:01 -55.1686 -57.9680 3106 3148 11 0 26 2016/01/10 15:01 -55.1171 -57.9682 2691 2721 8 0 27 2016/01/11 10:01 -55.0685 -57.9750 2186 2209 8 0 28 2016/01/11 12:01 -55.0067 -57.9782 1673 1683 8 8 29 2016/01/11 17:01 -54.9779 -57.9827 1062 1063 8 8 30 2016/01/11 18:01 -54.9224 -57.9825 712 711 6 0 31 2016/01/11 20:01 -54.6668 -57.9830 166 158 4 0 8.1 CTD Systems Operation One stainless steel CTD system was prepared with a 24-way carousel. The details of the instrumentation are given in Section 11. The instrumentation on the underwater package operated normally on the 31 stations conducted during the cruise, with two exceptions. 1) During station 16, both temperature and conductivity sensor pairs diverged. Comparison with bottle salinity data showed that the secondary sensor was in error, and as the processed data default to using the primary sensor, no change to processing was required. Flushing with a detergent solution fixed the problem, so no further action was taken. 2) One beam of the LADCP was not functioning (zero amplitude) during the first four casts; the LADCP was switched for a backup unit (see Section 11). 8.1.1 CTD operation and processing Data were acquired with SeaSave V 7.22.3. SBE35 temperature data were uploaded using SeaTerm immediately after finishing a cast. SBE35 temperature data can be logged when a Niskin bottle is fired. If the SBE35 is set to 8 samples, it requires approximately 13 seconds to make a measurement, calculated as 8 * 1.1 seconds plus an overhead. Data are stored internally and must be downloaded at the CTD deck unit as a separate process from the CTD data transfer. The SBE35 data are then transferred as a collection of ASCII files. The SBE35 clock was initially set to the wrong date, requiring editing of the files after the fact (the processing matches by bottle number and merely searches for SBE35 data within a few days of the CTD casts to be compared, so accurate time stamps are not required). After each cast SBE processing software was run in three steps to export as text file (.cnv), to apply time alignment of oxygen data (5s for sbeox0Mm/Kg and sbeox0V, but note that the hysteresis correction is applied later in mexec processing, NOT here), and to apply a cell thermal mass correction for conductivity (alpha = 0.03. tau = 7.0000 on both primary and secondary). The resulting files have suffix align ctm. Following this processing, a batch script, BASSvp, was run to prepare a sound velocity profile and a CTD listing for transmission to the UK Met Office. This batch script also copied the raw and processed data onto the network drive, legdata. 8.1.2 Data Processing The CTD data processing followed the methods used on previous SR1b and other NOC MPOC cruises, using the mexec software suite. The initial SeaBird data conversion, align, and cell thermal mass corrections were performed using SBE Data Processing, Version 7.22.2 software. The network data drive, legdata, was linked to ctd/ASCII FILES/jcrfs ctd and ctd linkscript was used to copy files to fola and set up additional symbolic links to filenames following mstar convention. For each cast the following m-files were then run, using wrapper script ctd all part1: mctd 01, mctd 02a, mctd 02b, mctd 03, mdcs 01, mdcs 02. The processes completed by these scripts include read ASCII cnv data from ctd/ASCII FILES/ctd jr15003 001 ctm.cnv convert variable names from SBE names to mexec names using data/templates/ctd jr15003 renamelist.csv copy raw file to 24hz file make oxygen hysteresis adjustment on 24hz file average to 1hz calculate dereived variables psal, potemp extract information from bottom of cast identified by maximum pressure. Subsequently mdcs 03g was run to inspect the profiles and hand-select cast start and end times. The way oxygen time lag is handled in the SBE align algorithm, and the weak dependence of oxygen calculation on salinity, means that when air is ingested into the conductivity cell at the end of the cast, the oxygen becomes biased a few seconds earlier than the psal. Care should therefore be taken to select a cast end time for which all the important variables are free from bias. The mdscs 03g program was modified so that the pressure record is coloured red at times when the CTD pumps status indicated that the pumps were off. This highlighted one instance (station 15) where the pumps went off when the package was hauled too close to the surface after soaking. On that station it was necessary to delete approximately the first 27 metres of the downcast, until the pumps restarted and the sensors stabilised. The start, bottom and end data cycles are stored in files with names like dcs jr15003 001.nc. After selecting the limits for start and end, ctd all part2 was then run, executing mctd 04, mfir 01, mfir 02,mwin 01, mwin 03, mwin 04. The processes completed by these scripts include Extract down and upcasts using scan numbers stored in dcs jr15003 001, and average into 2 dbar files (2db and 2up) Read the data/ctd/ASCII FILES/ctd jr15003 001.bl file and extract scan numbers corresponding to bot- tle firing events. Add time from CTD file, merging on scan number Add CTD upcast data (P,T1,T2,S1,S2, etc) corresponding to bottle firing events Paste these data into the master sample file data/ctd/sam_jr15003_001.nc Load winch telemetry data from winch SCS file Add winch wireout data to the fir jr15003 001 file Paste winch wireout data into the master sample file Processed data could then be examined using mctd checkplots to view sensor and up-down cast differences as well as compare nearby profiles, with particular attention paid to any drift in deep tem- perature or salinity (expected to be relatively stable) over time. The 24-Hz data were checked for spikes in either of the temperature or conductivity sensors using mctd rawshow and, if necessary, edited using mctd rawedit. A variety of extra steps is available after other processing has been carried out; these steps can be run in any order. After LADCP processing has been completed there is a best estimate of water depth available from the LDEO IX processing. This is found in cast processing log files by searching for “bottom found at”; the list of stations and depths is placed in station depths/station depths.txt. populate station depths can be run to convert station depths jr15003.txt to station depths jr15003.mat, which is the file required by mdep 01. populate station depths.m also allows missing depths to be set or bad depths to be overwritten using switch/case for each cruise. After navigation data processing has been completed the file data/nav/seapos/bst jr15003 01 will be available. mdcs 04 will generate files dcs jr15003 001 pos.nc which include position at start, bottom and end of profiles. mdcs 05 will then paste the position at the bottom of the cast into the header of all relevant files in data/ctd. mdep 01 and mdcs 05 can be run multiple times. The headers will not be updated if the updating values are identical to the values already in the file. 8.2 Water Sample Analysis Dissolved oxygen analysis is described in Section 9. For each CTD cast, one water sample was drawn per Niskin bottle for salinity analysis, from bottles that were fired, up to 12 per station. The distribution of bottle sample locations in Drake Passage is shown in Figure 2 and 3. Samples were taken in 200ml glass sample bottles, which were rinsed three times and sealed with a new clean dry disposable plastic stopper, after drying the neck of the bottle. The crate was then transferred to the bench in the Prep Lab. Caps were rinsed in freshwater and dried before being added to secure the stoppers. Samples were stored in the Bio Lab for a minimum of 8 hours before analysis to allow equilibration to the laboratory temperature (the conductivity ratio drift mentioned above did not appear to be connected to length of time samples had been in the lab). A logsheet was maintained of when crates were moved into the Bio Lab to keep track of when they would be ready to analyse. Salinity sample analysis was performed on the BAS Guildline 8400B Salinometer, Serial No. 65763, in the Bio Lab. The temperature of the ship air conditioning fluctuated throughout the cruise and we had considerable trouble keeping the autosal lab within the desired temperature range. We started by using a bath temperature of 24 C and attempting to keep the lab temperature between 21 and 22.5 C, but towards the end of the cruise we were unable to get the lab temperature above 17 C, so we switched the bath temperature to 21 C. The autosal did appear to be able to maintain a constant bath temperature, with the heater lights switching on and off as expected while it was in use. However, conductivity ratio readings for many sets of samples took an unusually long time to stablise. All watchkeepers carried out the analysis following standard procedure. A sample of IAPSO Standard Seawater was run before and after each set of up to 24 samples for salinometer calibration. We used Standard Seawater batches P156 and P158, with K15 values of 0.99984 and 0.99970, respectively. Standard seawater batch P156 was used to analyse samples from stations 1-14 and the first set of tsg samples, and batch P158 was used for stations 158 and the second set of tsg samples. We flushed the volume with expired P155 before starting new sets of runs to bring it closer to the standard salinity, and with milli-Q for intervals between runs. Bottle sample conductivity readings were read from the autosal and logged by hand as we did not have a laptop capable of running autosal 2009 or connecting to the autosal. Three readings were taken for each sample. In some cases, where the values did not stabilise (see above), four or more readings were taken, but, because drawing down the sample bottle volume permits more evaporation, readings past the third were not used. Due to the stabilisation problem (see above) all readings were examined, and a few outlier readings were excluded. Before comparison with the CTD data, the sample readings are adjusted for the salinometer off- set, or the difference between the standard reading and its label value, by linearly interpolating be- tween the initial and final standard for each set of samples. These offsets ranged from 1.03 10-3 to 1.41 10-3 (2xK15) for all but the last two sets of samples, with drifts within a sample set of 0.05 10-3 to 0.10 10-3. Offsets for the last two sets of samples, run at a higher bath temperature, were 3.8 10-3 to 5.8 10-3 (2xK15). These sets comprised the second set of tsg samples and CTD casts 30 and 31. Bottle-sensor conductivity differences stations 30 and 31 were not different from those for other stations. Samples from sets analysed using batch P156 (stations 1-14) were further adjusted for the batch- batch offset between P156 and P158. This offset of 0.6 10-3 psu was supplied by H. Uchida (pers. comm.) based on laboratory measurements following Kawano et al. (2006). The scatter in bottle-CTD comparisons was too large for this offset to be visible in this dataset. 8.3 Data calibration After calibration sample data were obtained, they were read in using msbe35 01, msbe35 02, msal 01y, msal 02, moxy 01y, moxy 02, and concatenated into master sample file sam jr15003 all.nc for comparison with sensor temperature, salinity, and oxygen. These comparisons were made ashore after the cruise. The locations of calibration samples from Drake Passage are shown in Figures 2, 3, and 4. Constant temperature offsets of -4 10-40C (-8 10-40C) were applied first using temp apply cal. 344 Niskin bottle salinities samples were analysed. During comparison with CTD conductivities us- ing ctd evaluate sensors, 20 of these comparisons were judged to be questionable or bad, either due to questionable bottle analysis or to strong salinity gradients, and were flagged accordingly. Based on the 324 good conductivity comparisons calibration factors with linear pressure and station number de- pendence were applied to the two sensors to minimise the median of the bottle conductivity to CTD conductivity ratio. These factors, applied using cond apply cal, were approximately equivalent to salinity offsets of (5.38 to 4.09) 10-3 psu at the surface and (0.6 to -0.69) 10-3 psu at 5000 dbar for the primary sensor, and (2.48 to 1.64) 10-3 psu at the surface and (-3.73 to -4.57) 10-3 psu at 5000 dbar for the secondary sensor (with factors in both cases decreasing over time). After temperature and conductivity calibrations were applied, oxygen was converted from µmol/L to µmol/kg using msam oxykg, and bottle and sensor values compared using ctd evaluate oxygen. 166 bottles were analysed for oxygen, but 2 of the comparisons were flagged as questionable. The calibration function obtained by least-squares fitting to the bottle data, and applied by oxy apply cal, was Ocal = O0(1.0603 + 0.0005N) + (1.0384 + 0.0007P), where Oo is the uncalibrated CTD oxygen, N is the station number (1 to 31), and P is pressure. 8.4 Lowered Acoustic Doppler Current Profiler (LADCP) 8.4.1 Instrument setup and performance The 300-kHz Workhorse LADCP was installed in a downward-looking configuration on the CTD rosette (see Section 11). The instrument was configured (Table 3) to sample 16 x 10m 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 prior to each station and data download after each station, using BBTalk. Pre-deployment tests were performed at least once daily. Data downloaded after each station were copied to the legwork portion of the network drive in ladcp/JR15003, with names of the form JR15003 NNN.000, along with deployment logs, JR15003 NNN.txt. Table 3: LADCP deployment commands, contained in JR15003_ladcp.cmd. CR1 RN JR15003 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 EZ001110 1 EX00100 CF11101 CK CS 8.4.2 Data processing Data for each station were processed on fola using the LDEO-IX software package, developed at Lamont-Doherty Earth Observatory (LDEO). The software uses an inverse method to calculate veloc- ity profiles, optionally including LADCP bottom tracking and/or VMADCP upper ocean velocities as constraints. At-sea processing was performed using only ship navigation (ladcp/ix/DL GPS) or navi- gation and bottom tracking (ladcp/ix/DL BT). The LADCP profiles in Drake Passage produced by the LDEO-IX inverse including navigation and bottom tracking are shown in Figure 5. There is a link to the ladcp directory on legdata: cruise/data/ladcp/raw/rawdata → ../../jcrfs/current/work/ladcp/JR15003/. After a cast, unix script exec/lad linkscript ix is run to update the raw data directory (calling exec/lad syncscript) and making links to files with IX processing name convention files. lad linkscript ix will need to be edited for the cruise name. Linking to CTD data Each processing suite also expects CTD filenames to have a certain form. 1-Hz CTD data can be exported from mexec into ascii using the mexec command list ctd 1hz(nnn) for station number nnn. This exports the variables time, press, temp, psal, latitude, longitude. Note that lat and lon are required for the IX processing, and become the source of navigation data for that suite. If list ctd 1hz has been run from Matlab, then ladctd linkscript ix will make those ascii files available to the IX processing in the correct locations and with the correct file names. In IX, links to CTD data are made in ladcp/ix/data/CTD/1Hz/ctd → ctd and ladcp/ix/data/CTD/1Hz/ctd jr15003 028 1hz txt ctd/ctd jr15003 028 1hz txt. ladctd linkscript ix should not require modification for each cruise. Edits to .m files required at start of a cruise for IX processing In addition to setting up directories, links and linkscripts, the set cast params*.m files must be edited with cruise details. These scripts reside in data/ladcp/ix/data/. Edits required (lines from jr15003 set_cast_params*.m shown): f.sadcp = sprintf(’SADCP/os75_jr15003_ctd_%03d.mat’,stn); f.ctd = sprintf(’CTD/1Hz/ctd_jr15003_%03d_1hz_txt’,stn); p.cruise id = ’jr15003’; p.whoami = ’Y. Firing’; The different versions of set cast params*.m are called by different versions of process cast*.m to run IX processing of the LADCP data with different constraints: • process cast v5.m calls set_cast_params_v5.m to include only navigation data • process cast v4.m calls set_cast_params_v4.m to include navigation and bottom tracking data • process cast v3.m calls set_cast_params_v3.m to include navigation, bottom tracking, and VMADCP data set_cast_params.m (and thus process_cast.m) are currently set to use v5 (navigation only). Quick look notes for LADCP processing in IX 1. Make sure the raw file is on legdata: cd /cruise/data/ladcp/raw ls ld rawdata/* (see files on legdata) ls ld * (see files on fola) The latest station should have a name like rawdata/JR15003 002m.000. 2. Run unix script lad_linkscript_ix. This will find any files in legdata that aren’t on fola, copy them across to the correct place on fola using rsync, and create links in the IX processing tree so that IX is aware of the raw files: ladcp/ix/data/raw/002/002DL000.000→ ../rawdata/JR15003 002m.000 and so on. This script can be run from anywhere, and will echo to the screen the identity of any files copied and any links made. Check again using step 1 if you wish. 3. Run unix script ladctd_linkscript_ix. If the CTD 1-Hz ASCII file is available, this will make a link in the IX processing tree so that IX is aware of the CTD data: ladcp/ix/data/CTD/1Hz/ctd_jr15003_nnn_1hz.txt→ctd/ctd_jr15003_nnn_ 1hz.txt. IX can be run without CTD data for first-look checking, but it will produce an error in calculating the magnetic variation, because position is unknown and is found in the CTD 1-Hz file. If you know the CTD file is not available, skip this step. 4. If you intend to run process cast v3 to use VMADCP data, check that ladcp/ix/data/SADCP/os75_jr15003_ctd_028.mat is available. 5. Run the IX process: cd ladcp/ix/data or cd /cruise/data/ix (an abbreviation: ix→ladcp/ix/ data) matlab & >> ixpath >> process_cast(nnn), where nnn is the station number. 6. Repeat steps 3, 4 and 5 as CTD and VMADCP data become available. 7. Note that on jr15003 there are three versions of process cast available. process_cast_v5 calls set_cast_params_v5, and processes data into DL_GPS/. Navigation is used but no BT or VMADCP constraint. process_cast_v4 calls set_cast_params_4, and processes data into DL_BT. Navigation and BT are used but no VMADCP constraint. process_cast_v3 calls set_cast_params_v3, and processes data into DL_BT_GPS. Navigation, BT, and VMADCP are all used. 8.5 References Kawano, Takeshi, Michio Aoyama, Terry Joyce, Hiroshi Uchida, Yasushi Takatsuki, and Masao Fuka- sawa, 2006, J. Oceanogr., 62, 777-792. Figure 2: Calibrated temperature on SR1b, with bottle firings (corresponding to SBE35 samples) shown by black circles and float deployment stations by squares. Figure 3: Calibrated salinity on SR1b, with bottle salinity samples shown by black circles and float deployment stations by squares. Figure 4: Calibrated dissolved oxygen on SR1b, with bottle oxygen samples shown by black circles and float deployment stations by squares. Figure 5: Profiles of zonal (top) and meridional (bottom) velocity from LADCP at each station in Drake Passage, offset to the latitude of that station, with dashed zero lines. Right hand panels show northern profiles including the Subantarctic Front jet, with a common zero line. 9 SOCCOM (SOUTHERN OCEAN CARBON AND CLIMATE OBSERVATIONS AND MODELING) FLOAT DEPLOYMENTS AND CTD STATIONS Daniel Schuller The SOCCOM (Southern Ocean Carbon and Climate Observations and Modelling) project implements sustained observations of the carbon cycle, together with mesoscale eddying models linked to the observations. 180 to 200 autonomous profiling floats with biogeochemical sensors (oxygen, nitrate, pH and optical sensors in addition to temperature/salinity) and sea-ice avoidance software will be deployed throughout the Southern Ocean during this project. These floats will extend current seasonally limited observations of biogeochemical properties into nearly continuous coverage in time, with horizontal spatial coverage over the entire Southern Ocean and vertical coverage to 2000 m. These float deployments must take place from research ships with CTD/rosette sampling in order to collect water samples (to be analysed for oxygen, nutrients, pH, alkalinity, HPLC, POC) for float profile calibration. This is the 2nd year of the project; multiple floats have been deployed from foreign and domestic re- search vessels including Nathaniel B Palmer, Polarstern, and James Clark Ross. All floats deployed are operating well as of the end of the cruise, with data reported in near real-time and publicly available from: http://www.mbari.org/chemsensor/floatviz.htm. The pH sensor technology, which was developed recently, is proving to be very robust. The T/S data are part of the Argo float data set. The USA National Science Foundation (NSF) funds all measurements and calibration measurements, with the exception of the optical measurements. Optical measurements included in this plan have been proposed to NASA. The 4 floats deployed from JCR will contribute to the international Southern Ocean Observing System (SOOS) and the Argo database. 9.1 Float Deployments 4 SOCCOM floats deployed on JR15003 according to Table 4: Table 4: SOCCOM floats with deployment times and positions. I = ice enabled; O = oxygen sensor; N = nitrate sensor; F = fluorometer (WetLabs FLBB); p = pH sensor. Float ID Sensors CTD Deploy. Deploy. Lat Lon Deployer stn date time name ------------ ------- --- ---------- ------ ---------- ---------- -------- 1, 9652 Apex IONpF 009 7 Jan 2016 0335Z 60.66637 S 54.82753 W Schuller 2, 9657 Apex IONpF 012 7 Jan 2016 1732Z 59.66695 S 55.44552 W Schuller 3, 9655 Apex IONp 016 8 Jan 2016 1743Z 58.05023 S 56.44734 W Schuller 4, 9662 Apex IONp 020 9 Jan 2016 1502Z 56.46764 S 57.40497 W Schuller 9.2 CTD/Rosette Sampling CTD casts were completed at each SOCCOM float deployment location for a total of 4 profiles. Full water column bottle samples were taken for dissolved oxygen, pH/alkalinity, dissolved inorganic nutrients, salinity, HPLC and POC at each station in that order. Dissolved oxygen was analysed on board. NOCS sampled and analysed water samples for salinity at these locations. 9.3 Dissolved Oxygen Samples were analyzed for oxygen at 4 SOCCOM stations and 11 additional stations. 9.4 Sampling and Data Processing Samples were collected for dissolved oxygen analyses as the first sample after the rosette was brought on board. Using a Tygon drawing tube, nominal 125ml volume-calibrated iodine flasks were rinsed three times then filled and allowed to overflow for approximately three flask volumes. The sample draw temperature was measured with a small thermometer embedded in the drawing tube. Reagents (MnCl2 and NaOH/NaI) were added to fix the oxygen before stoppering. The flasks were shaken twice to assure thorough dispersion of the precipitate, once immediately after drawing, and then again after about 20 minutes. The samples were usually analyzed within several hours of collection. Thiosulfate normalities were calculated from each standardization and corrected to 20C. The 20C normalities and the blanks were plotted versus time and were reviewed for possible problems. Oxygens were converted from milliliters per liter to micromoles per kilogram using the sampling draw temperature and the samples salinity. 9.5 Equipment and Techniques Dissolved oxygen analyses were performed with an ODF-designed automated oxygen titrator using photometric end-point detection based on the absorption of 365nm wavelength ultra-violet light. The titration of the samples and the data logging were controlled by LabView software. Thiosulfate was dispensed by a Dosimat 665 buret driver fitted with a 1.0 ml buret. The ODF method used a whole- bottle modified-Winkler titration following the technique of Carpenter (1965) with modifications by Culberson (1991), but with higher concentrations of potassium iodate standard (approximately 0.012N) and thiosulfate solution (55 g/l). Standard KIO3 solutions prepared ashore were run at the beginning of each run. Reagent and distilled water blanks were determined, to account for presence of oxidizing or reducing materials. 9.6 Volumetric Calibration Oxygen flask volumes were determined gravimetrically with degassed deionized water to determine flask volumes at ODFs chemistry laboratory. This was done once before using flasks for the first time and periodically thereafter when a suspect bottle volume was detected. The volumetric flasks used in preparing standards were volume-calibrated by the same method, as was the 10 ml Dosimat buret used to dispense standard iodate solution. 9.7 Standards Potassium iodate was obtained from Johnson Matthey Chemical Co. and was reported by the supplier to be >99.4% pure. 9.8 pH/Alkalinity Samples were taken from 4 SOCCOM stations and 1 additional station. Approximately 10% of samples were duplicates. Nominal 500 mL samples were drawn from the Niskin bottles, preserved with mercury (II) chloride and packed for shipping via air freight back for analysis at Scripps Institution of Oceanography. 9.9 Nutrients Samples were taken from 4 SOCCOM stations. Nominal 30 mL samples were drawn from the Niskin bottles into rinsed centrifuge tubes. They were immediately frozen in -20C freezer. Upon JCRs return to UK the nutrient samples will be shipped on dry ice via air freight for analysis at Scripps Institution of Oceanography. 9.10 Salinity Salinity samples were collected at all depths from the 4 SOCCOM CTD stations. Samples were analyzed shipboard by NOCS using JCRs Guildline 8400B autosal. 9.11 HPLC and POC HPLC/POC samples were taken from 4 SOCCOM stations and 6 additional stations. Samples were taken from the surface and cholorophyll maximum Niskin bottles. A duplicate sample was taken alter- nating between surface and chlorophyll maximum depths at each station as well. 1 L of seawater was filtered in the dark through glass fiber filters. Filters were immediately stored in aluminium foil packages in a dewar of liquid nitrogen. Filters and aluminium foil packets were pre-combusted for POC samples. Samples were moved to -80C freezer at the conclusion of the cruise. Upon JCRs return to UK samples will be shipped in a dry shipper back to Scripps Institution of Oceanography for analysis. 9.12 References Carpenter, J. H., “The Chesapeake Bay Institute technique for the Winkler dissolved oxygen method,” Limnology and Oceanography, 10, pp. 141-143 (1965). Culberson, C. H., Knapp, G., Stalcup, M., Williams, R.T., and Zemlyak, F., “A comparison of meth- ods for the determination of dissolved oxygen in seawater,” Report WHPO 91-2, WOCE Hydrographic Programme Office (Aug 1991). 10 UNDERWAY DATA COLLECTION AND PROCESSING 10.1 Computing and SCS data processing 10.1.1 Configuration of linux workstation ’fola’ The NOC MPOC OCP group brought a linux workstation (fola), which was the primary platform for data analysis during the cruise. The jcr cruise data directory was made available by mounting on fola. That directory includes SCS data streams, data from other sources such as CTD, LADCP, VMADCP, and the legwork directory. The network data directory was mounted on fola so that /mnt/data/cruise/jcr was the parent directory of the individual cruise data directories identified by date. Cruise jr15003 was current → 20151217. A link was made on fola in /local/users/pstar/cruise/data so that data/jcrfs → /mnt/data/cruise/jcr. This enabled access to the legdata directory as well as the legwork part of it. Since the current/ cruise directory sits below /mnt/data/cruise/jcr, useful directories could be accessed using the following example links: data/ctd/ASCII FILES/jcrfs_ctd → ../../jcrfs/current/ctd/JR15003 data/legwork → jcrfs/current/work data/vmadcp/jcrfs_adcp75 → ../jcrfs/current/adcp data/scs_raw_ship → jcrfs/current/scs/Compress Workstation fola was backed up on a daily basis. A complete dump of cruise data and software was copied using rsync from fola to one of two Transcend portable hard drives. These drives were used to carry data back to NOC at the end of the cruise, including a final identical backup of fola on two drives. 10.1.2 SCS data streams The SCS data streams (ashtech [nav/ash], ea600 [sim], anemometer [met/surfmet], oceanlogger [ocl], emlog-vhw [chf], gyro [nav/gyros], seatex-gll [nav/seapos], em122 [em122], seatex-hdt [nav/seahead]) were processed on fola during the cruise. Most were processed in 24-hour segments, using m_jr15003_daily processing.m, with cleaning and appending as required. Winch data were processed by CTD station as part of standard CTD processing (ctd_all_part2.m). 10.1.3 Access to SCS data SCS data are stored in *.ACO files, which are plain text. However, non-numeric characters make these slow to parse in Matlab. An ad hoc but fairly robust and quick-running system has evolved to make these data more easily readable for mexec processing. 1. Parse the ACO files with linux sed, to remove non-numerical characters. Input SCS files are in data/scs raw. On the ship and during the cruise, data/scs raw → scs_raw_ship, data/scs_raw_ship → jcrfs/current/scs/Compress. At the end of the cruise, the contents of scs_raw_ship are copied to a local directory, data/sca_raw_postcruise. Then the link is changed so data/scs raw scs_raw_postcruise, so that raw SCS files can be accessed after the cruise. The sed parsing allows continually-filling SCS files to be continually edited into data/scs sed/. Parsing is started and stopped with linux commands sedexec_startall and sedexec_stopall. If there is a problem with any aspect of sed processing, the safest action is to delete all of scs_sed/*ACO and stop and restart sedexec processing. The sedexec scripts live in data/exec/jcr. sedexec_startall needs a list of ACO files to parse. This can be generated by a Matlab script, data/exec/jcr/make list for sedexec_startall.m. This will make list_jr15003, linked to by data/exec/jcr/list. SCS files note 1 The SCS data consist of .ACO files and .TPL files. The TPL files contain lists of variables. When a cruise begins, the data/scs_raw/*.TPL should be copied to data/scs sed. oceanlog- ger.TPL needs to be manually edited, as oceanlogger.ACO has time information for which the number of fields changes when parsed through sed. The original oceanlogger.TPL begins thus: 126,oceanlogger-sampletime,YYY DDD HH:MM:SS 127,oceanlogger-airtemp1,celsius 128,oceanlogger-humidity1, 129,oceanlogger-par1,umol/S.m2 so the first line must be replaced with 3 lines thus: 126,oceanlogger-sampletimeyyyy,YYYY 126,oceanlogger-sampletimeddd,DDD 126,oceanlogger-sampletimehhmmss,HH:MM:SS 127,oceanlogger-airtemp1,celsius 128,oceanlogger-humidity1, 129,oceanlogger-par1,umol/S.m2 SCS files note 2 The default SCS variable names include the name of the data stream for each variable. e.g. oceanlogger-humidity1. The daily processing of SCS files removes the extra part of the variable name. The new names need to be in lookup template .csv files in data/templates. For example the first few lines of the oceanlogger template, data/templates/scs jr15003 renamelist oceanlogger.csv, are oceanlogger sampletimeyyyy,sampletimeyyyy,YYYY oceanlogger_sampletimeddd,sampletimeddd,DDD oceanlogger_sampletimehhmmss,sampletimehhmmss,HH:MM:SS oceanlogger_airtemp1,airtemp1,celsius oceanlogger_humidity1,humidity1, The set of required template files can be made in Matlab with ms_generate_varname_translation_all.m, which makes successive calls to ms_generate_varname_translation(stream). If this script fails, templates can be copied from a previous cruise. The template contents will be unchanged unless the variables in the SCS file have changed, e.g. a new sensor in the oceanlogger stream. 2. Convert ACO text files to Matlab. Even the clean and numeric ACO files are too slow to routinely read into Matlab to access data ’on demand’. Therefore a process is run in which Matlab versions of the SCS data are accumulated into data/scs mat/. In a Matlab window, the command ms update aco to mat(’ea600’) will read data from data/scs sed/ea600.ACO and save the data in data/scs mat/ea600.mat. This process also notes the number of bytes of the ACO file converted. Next time the process is run, those bytes are skipped so that only new data are converted. The command update allmat will update all the SCS streams with multiple calls to ms update aco to mat. update allmat will need to be edited to add new streams if new SCS streams are required, otherwise it does not require any modification at the start of a cruise. Some Matlab scripts (eg mday 00.m) that read data ’up to the present’ call the update script before loading data. Sometimes it is necessary to run the update script manually from the command prompt, to ensure all ACO data are available to following scripts. If the scs sed files have got into a mess and been regenerated or scs sed parsing restarted, the safest course of action is to delete the contents of scs mat and run update allmat. This takes a few minutes at the start of a cruise and rather longer, maybe up to half an hour, if 30 or 40 days data are waiting to be parsed. This is necessary because the scs mat file keeps a count of the number of bytes of the ACO file parsed. If the ACO file has been altered before that byte count, the ms update aco to mat process may fail to copy the data correctly, but may not give an error. 10.1.4 The mscs source directory The mscs source directory cruise/sw/mexec v2/source/mscs contains the scripts for accessing the SCS data either directly or via scs mat. Some of the scripts, e.g. scs to mstar2.m are called by wrapper scripts such as mday 00.m. Some of the scripts can provide quick access to SCS data that have not yet been processed into mexec files. Examples include: msgaps, mslast, mslistit, msload, mslookd (usually run as mslookd f), msnames, msposinfo, msposinfo noup (quick version for finding ship position at earlier time so not necessary to update scs mat/ first), msvars. See help mscs for further information. The techsas equivalent library has help mtechsas which has extra documentation and help. 10.2 Underway surface water sampling 10.2.1 Underway surface thermosalinograph The list of oceanlogger variables is as follows: mexec directory mexec short mexec mexec file variables name directory root abbreviation --------------- ----------- ------------ ---------- -------------- ocl oceanlogger M_OCL ocl tstemp conductivity salinity sound velocity chlorophyll sampletemp flowrate sstemp trans sstemp2 Note the alternative temperatures: sstemp and sstemp2 for seawater intake, sampletemp for fluorometer sample temperature, tstemp for the SBE housing temperature for calculation of salinity. A total of 41 underway samples were analysed for oceanlogger salinity calibration. Samples were drawn from the underway supply in the Prep Lab as often as every 4 hours during science time in ice- free areas, following the same procedure as for Niskin bottle samples, and the time noted in a logsheet to the nearest minute. Samples were analysed following the procedure described for CTD salinity samples. Data were read in as part of the daily processing. Data were set to absent at any time that the pumps were known to be off, either close to port, in ice, or where the flowrate indicated there was little or fluctuating supply. Relatively simple cleaning has been applied to the appended dataset using mtsg medav clean cal and mtsg findbad. Based on comparison with the bottle salinities an offset of 0.06 psu was applied to the oceanlogger salinity record using mtsg apply salcal. 10.3 Surface water sampling for Nd isotope analysis In Bransfield Strait and Drake Passage, several samples from the pumped surface water supply were taken in 10 L cubitainers, acidified, and stored for Nd isotope analysis ashore. 10.4 Daily processing of SCS streams As part of the regular watchkeeping logging every 4 hours, we checked that the SCS streams were up- dating with reasonable values. Data were transferred from the onboard logging system (SCS) to fola daily using mday 00 get all.m. This script also appends daily data files for streams other than bathymetry (see below). Table 5: Times (from log sheet) and locations (from ship track) of surface water samples for Nd isotope analysis Sample Name Date Time Latitude (S) Longitude (W) Sampler ----------- ---------- ----- ------------ ------------- ------- Surface-01 23.12.2015 1600Z 61027.77’ 52001.62’ TC Surface-02 24.12.2015 0215Z 62020.27’ 55055.86’ TC Surface-03 24.12.2015 1145Z 63006.69’ 59008.58’ TC Surface-04 06.01.2016 1249Z 60050.94’ 54042.45’ YF Surface-05 07.01.2016 0354Z 60037.84’ 54051.05’ YF Surface-06 07.01.2016 0822Z 60019.08’ 55002.44’ CdL Surface-07 07.01.2016 1249Z 60000.07’ 55013.92’ CdL Surface-08 09.01.2016 0428Z 57015.50’ 56056.27’ DB 10.4.1 Navigation The list of navigation streams processed from SCS was given in Section 10.1.2. After daily process- ing of SCS streams, navigation processing steps can be completed on the appended xxx jr15003 01.nc files. The steps are combined into a single wrapper mbest all.m. This script performs tasks such as subsampling to 30-second intervals, adding ship speed and course over ground, and merging on ship heading. Ship headings are properly vector averaged when subsampled. A best navigation file, data/nav/seapos/bst jr15003 01.nc, is the final output. 10.4.2 Surface meteorological sampling (SURFMET) RRS James Clark Ross is equipped with a variety of meteorological sensors to measure air tem- perature and humidity, atmospheric pressure, total irradiance, photosynthetically active radiation, wind speed and wind direction throughout the cruise. The radiation and pressure variables were logged in data/met/surflight/. The remaining data were logged in /met/surfmet. The raw data files have extensions of the form jr15003 dNNN raw.nc, where NNN represents the day number. Once the best navigation file is available, mtruew 01.m is run to combine ship navigation data with relative data from the anemometer to produce absolute and relative winds averaged to 1-minute resolution. As with best navigation, all headings are properly vector averaged, and the final product is the file data/met/surfmet/ met_jr15003_trueav.nc. 10.4.3 Bathymetry The EM122 swath echosounder was turned off for the SR1b section (along which bathymetry has been measured on many previous cruises) in an attempt to improve the noisy VMADCP data (see below). The raw data files have extensions of the form jr15003 dNNN.nc where NNN is the number of the Julian day. msim 01.m was run to remove data outside a tolerated range and apply a 5-minute median despiking, outputting the file sim jr15003 dNNN smooth.nc. msim plot.m copied the smoothed sim data to the file sim jr15003 dNNN edited.nc and called mplxyed to allow a manual removal of the remaining spikes in sim data; mem122 plot.m was run to do the same for the em122 data (note that each script must be used to edit the correct data type; sim must be edited in msim plot and em122 in mem122 plot). Two bathymetry streams are available via SCS: the ea600 single-beam echo sounder, and the centre beam of the em122 multibeam (swath) system. Data are read in by the daily processing (mday 00 get all.m); for day number 014 (for instance), ea600 and em122 data are read into sim/sim jr15003 d014.nc and em122/em122 jr15003 d014.nc, respectively. For streams other than bathymetry, daily processing ap- pends each day onto a growing appended file, but the bathymetry records require manual editing before they can be appended, so there is no append action for sim or em122 in the daily processing. After editing (see below) they are appended using mday 02. The bathymetry streams inevitably contain bad data where the automatic digital determination of depth has failed to correctly infer depth from the analog signals. As the original analog records are not generally available to the person doing data editing/cleanup, some judgement is required to decide what are good or bad data. In order to aid this process, there is a display of both of the two data streams, along with an estimate of bathymetry from satellite gravity data. Thus the ea600 data are edited by reference to em122 data, and vice versa. There is a symmetric set of scripts for cleaning the two data streams. The first step is to do some automated cleanup of both the ea600 and em122 streams, with msim 01 and mem122 01. Both must be run before proceeding with manual graphical editing. 10.4.4 EA600 For ea600, the process is as follows: • msim 01 reads raw data for the day (from e.g. sim_jr15003_d014_raw.nc); picks data in the depth range 5 to 10000, to discard zeros; takes the median depth over 300-second bins, to discard noise (example output file: sim_jr15003-d014_smooth.nc) makes duplicate file in sim_jr15003-d014_edited.nc • msim 02 merges on swath centre beam data for the day (if available) to be used in cleaning. Note that mem122_01.m must be run before this step. • msim plot calls mplxyed for manual removal of bad data. Note that the files are set up so this file is used to edit bad data in the ea600 file. The equivalent file in the em122 sequence should be used to edit bad data in the em122 stream.msim_plot displays an extra window with the full ea600 data, to guide the use of mplxyed. EA600 data quality: data editing was done somewhat conservatively, so the cleaned records likely still contain noise. • After cleaning in mplxyed, daily files were appended into a single file, sim jr15003 01.nc, by running mday 02 (see mday 02 run all). At this stage, the em122 depths used for data quality checking are discarded. • Next, using the script mmerge_sim_nav_jr15003, navigation was added, in sim_jr15003_01_nav.nc, and a Carter area correction applied, using mcalc, in sim_jr15003_01_nav_cordep.nc. This last file is therefore the master EA600 file, containing corrected bottom depths in 5 minute bins. 10.4.5 EM122 Em122 centre beam depths were logged in SCS and downloaded in daily files to em122/. Two scripts are used to reduce and edit EM122 data, based on the scripts for EA600: • mem120_01 reads raw data (from e.g. em122_jr15003_d014_raw.nc), runs mdatpik to require depth > 20 m, runs mavmed to take the median over 300-s bins, producing em122_jr15003_d014_smooth.nc, and copies the file to an ’edited’ version (em122_jr15003_d014_edited.nc) ready for manual editing. • mem120 02 merges on ea600 for display in mplxyed for QC. • mem120 plot plots data for editing: if all the relevant files exist, displays the Matlab window with EM120, EA600 and satellite bathymetry, then enters mplxyed on the edited file. This step can be repeated as often as required. The Matlab plot window displays the data as found in the most recently updated ’edited’ file. The cleaned data are then appended using mday 02 (see above). 10.4.6 Chernikeef EM log Chernikeef EM log data were recorded and downloaded daily. Besides appending the files, no further processing was carried out and the calibration of the EM log was not checked. 10.5 Vessel Mounted ADCP A vessel-mounted 75-kHz Teledyne RD Instruments (RDI) OceanSurveyor Acoustic Doppler Cur- rent Profiler (ADCP) was run throughout the cruise to measure horizontal velocity from 30 m to approxi- mately 400-800 m. The depth of the transducer is 5 m. The phased-array transducer should be insensitive to sound speed (temperature) changes (but see discussion below). The data may be particularly affected by bubbles under a certain range of ship heading relative to the seas, which appears to have dramatically reduced data quality at a few of the CTD stations. Coordinating pinging with the EM122 was not successful in deeper water (see below), and in some cases there appeared to be intereference from or with the bathymetric echosounders. The data quality is generally uncertain and the data will be reprocessed, edited, and evaluated ashore. 10.5.1 Real-time data acquisition and VMDAS files The data from the instrument were acquired using the RDI VMDAS software package version 1.42, installed on a PC in the main laboratory. The software allows data acquisition in a number of configurable formats and performs preliminary screening and transformation of the data from beam to Earth coordinates. A perl script to subsample ship navigation data, NavigationRepeater, must be run on the same machine throughout data collection. VMDAS was run using a selection of preset configuration files (selected under “edit data options”) which allowed the instrument to be promptly switched between bottom tracking and water tracking; set for different depth ranges; and self-triggered or triggered by the K-sync unit (see below) so as not to interfere with other acoustic measurements. More detail on settings is given below. Data collection was typically stopped and restarted, generating a new file segment num- ber, daily during the cruise, to facilitate incremental processing. Files were automatically placed on the network legdata/adcp directory and rsynced to fola daily using vmadcp linkscript. The files produced have names of the form JR15003 os75nnn mmmm.ext, where nnn is the file sequence number, mmmm is the number of the segment file within the sequence and ext is the extension. A new segment file is automatically started when one of the file types reaches a size of 10 Mb. VmDas automatically increments the file segment number every time data collection is stopped and restarted. The ’R’, ’S’ and ’L’ tabs on the VmDas menu bar allow the user to swap between graphical output from the .ENR, .STA and .LTA files. When in ’R’ mode, the default upper left hand display in VmDas is the raw velocity parallel to each beam, while ’S’ (short-term average) and ’L’ (long-term average) modes display currents averaged over 2 or 10 minutes, in Earth coordinates. Various display options are available but data were generally monitored in either raw or short-term average form, and checked in more detail following daily processing. During the every-4-hours regular watchkeeping tasks the VMADCP ensemble number was checked to ensure the expected amount of data recording. As on previous cruise JR306, the ensemble number reset itself at various points, for unknown reasons (i.e., not wrapping over at any obvious or consistent number). We did not check if this led to any missed pings; 5-minute ensemble averages did not appear to be affected. 10.5.2 Settings The VMADCP was run in single-ping mode, with an 8-m pulse, 100 8-m bins, and an 8-m blanking distance. In shallow water (<500 m generally), the instrument was run in bottom track mode to obtain phase and amplitude calibrations, and set to have fewer bins (reduced depth range) to enable more- frequent pinging. In deeper water the instrument was switched to watertrack mode, and watertrack calibration data were obtained during CTD station-keeping. The island stops on this cruise resulted in a number of potential bottom track segments. For some of the cruise the VMADCP was set to be triggered by the K-sync system in order not to interfere with the bathymetric echosounders. In deeper water (in Drake Passage) the EM122 triggered so infrequently that the ADCP repeatedly timed out while waiting for a ping command, resulting in resetting, and collecting little to no data. When the EM122 was set to ping at a set interval, with the ADCP pinging in between, data quality of both instruments degraded. Where possible, therefore, we turned off the EM122 (for instance along SR1b, where swath bathymetry has been collected on the identical track many times before). K-sync settings were modified as follows (saved as physics800): disable EM122 in uncheck “echo sounder is master” enable EA600, OS75 set fixed periods: EA600 1 s, OS75 3.5 s (necessary interval for 800 m range) trigger groups 1, 2, 3: OS75 trigger group 4: EA600 At times there also seemed to be interference in the EA600, which was attributed to the OS75, although it is unclear whether this was actually the cause. Since bathymetry data were most wanted outside Drake Passage (where the tracks we followed have been covered multiple times already), we switched off the VMADCP for those segments. 11 INSTRUMENTATION, EXTRACTED FROM AME REPORT Paul Morgan Table 6: Lab instruments used Instrument S/N Used Comments ---------- -------- -------- Autosal 63360 Table 7: Acoustic instruments used Instrument S/N Used Comments ------------------------------ -------- -------- ADCP Y EM122 Y TOPAS Y EK80 Y 10kHz IOS pinger Benthos 12kHz pinger + bracket 1316 Table 8: Oceanlogger Instrument S/N Used Comments ------------------------- -------- ----------- Barometer1(UIC) 5002 Barometer1(UIC) 5003 Foremast Sensors Air humidity & temp1 3898 Air humidity & temp2 3896 TIR1 sensor (pyranometer) 2993 Not working TIR2 sensor (pyranometer) 2992 Not working PAR1 sensor 0127 PAR2 sensor 0126 prep lab Thermosalinograph SBE45 0016 Transmissometer 396 Fluorometer 1100243 Flow meter 811950 Seawater temp 1 SBE38 0601 Seawater temp 2 SBE38 0599 Table 9: CTD Instrument S/N Used Comments -------------------------------- ----------- ------------------------ Deck unit 1 SBE11plus 0458 Underwater unit SBE9plus 0707 Temp1 sensor SBE3plus 2705 Temp2 sensor SBE3plus 5766 Cond1 sensor SBE 4C 2248 Cond2 sensor SBE 4C 4471 Pump1 SBE5T 1807 Pump2 SBE5T 7606 Standards Thermometer SBE35 0024 Transmissometer C-Star 846 Oxygen sensor SBE43 0676 PAR sensor 7274 Fluorometer Aquatracka 088-249 Altimeter PA200 163162 LADCP 15060/14897 Changed to 14897 due to loss of beam intensity CTD swivel linkage Changed due to damage when CTD stowed away Pylon SBE32 0636 Table 10: AME unsupported instruments logged Instrument S/N Used Comments ---------- -------- -------- EA600 Y Anemometer Y Gyro Y DopplerLog Y EMLog Y 12 Acknowledgments We are sincerely grateful to the Master, officers, and crew, who were enthusiastic, helpful, and ac- commodating throughout the cruise. We would like to thank volunteers Lucie Cassarino, Tianyu Chen, Damien Desbruyeres, Casimir de Lavergne, David Byrne, Jennifer Mecking for their tireless work throughout the cruise, and Daniel Schuller for his assistance and advice with SR1b water sampling and calibration in addition to his float duties. CCHDO Data Processing Notes • File Online Carolina Berys 74JC20151217.exc.csv (download) #7aca5 Date: 2016-09-12 Current Status: unprocessed • File Submission Robert M. Key 74JC20151217.exc.csv (download) #7aca5 Date: 2016-09-08 Current Status: unprocessed Notes Update: Shore based nutrients added shore based alk and pH added header edited • File Online Carolina Berys NOC_CR_38.pdf (download) #ebcfd Date: 2016-07-18 Current Status: unprocessed • File Submission Yvonne Firing NOC_CR_38.pdf (download) #ebcfd Date: 2016-07-15 Current Status: unprocessed • File Online Carolina Berys sr1b_74JC20151217_hy.csv (download) #d6318 Date: 2016-07-11 Current Status: unprocessed • File Online Carolina Berys sr1b_74JC20151217_ct1.tar.gz (download) #34ca5 Date: 2016-07-11 Current Status: unprocessed • File Submission Yvonne Firing sr1b_74JC20151217_ct1.tar.gz (download) #34ca5 Date: 2016-07-07 Current Status: unprocessed Notes Cruise JR15003, 17 December 2015 - 13 January 2016, including GO-SHIP line SR1b (SR01). Temperature, salinity, and oxygen are calibrated, other variables uncalibrated. • File Submission Yvonne Firing sr1b_74JC20151217_hy.csv (download) #d6318 Date: 2016-07-07 Current Status: unprocessed Notes Cruise JR15003, 17 December 2015 - 13 January 2016, including GO-SHIP line SR1b (SR01).