Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Dr. Dagmar KiekeInstitut für UmweltphysikAG OzeanographieUniversität BremenOtto-Hahn-Allee 1D-28359 BremenGermanyTel.:Fax:email: 49-421-218-62154 [email protected] Cruise Report- RV Maria S. Merian, cruise MSM-64 Southampton/UK – Galway/Ireland – St. John's/Canada27 May – 23 Jun 2017Chief Scientist: Dr. Dagmar KiekeCaptain: Björn MaaßFigure 1. Track of RV MARIA S. MERIAN, cruise MSM-64, and locations of hydrographic profiles (red,numbers denote profile numbers), deployed moorings (yellow), inverted echo-sounders with pressuresensors (PIES, white), and Argo float deployments. Bathymetric contours are shown every 1000 m.1/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 20171. ObjectivesPhysical oceanographic measurements conducted during cruise MSM-64 contributed tothe scientific project RACE-II (“Regional Atlantic ChangE”), sub-project 1.2, funded by theGerman Ministry for Education and Research (BMBF). Scientific work during cruise MSM64 emphasized on a detailed mapping of water mass properties along 47 /48 N that wascombined with comprehensive measurements of the current system. In addition to shipbased observations, recovery and redeployment of deep-sea moorings at the western andeastern boundaries of the North Atlantic was conducted. These serve to determine theexport and import rates of subpolar or subtropical water masses in these regions. Variouslocations within the deep basins have been equipped (partly since 2006) with invertedecho-sounders carrying pressure sensors (PIES) that allow capturing variations of thedifferent branches of the North Atlantic Current (NAC). Together with the deep-seamoorings these form the oceanic long-term observatory NOAC (“North Atlantic Changes”)deployed along 47 /48 N. In combination with satellite altimetry the data serve toinvestigate the main components of the Atlantic Meridional Overturning Circulation(AMOC) at this latitude.In addition to this program, the two multibeam echo-sounder systems installed in thevessel’s hull (Kongsberg EM-712 and EM-122) were calibrated, and the required seaacceptance test for the EM-712 device was carried out by a technical-scientific team. Dueto this, the cruise was split into two separate legs (Southampton-Galway, Galway-St.John’s) with personnel being exchanged in Galway/Ireland on June 02nd, 2017.The primary objectives of cruise MSM-64 were:1) to capture the strength and the variability of the eastern boundary current off GobanSpur at the Irish shelf edge, which required the recovery and redeployment of deepsea moorings2) to recover data recorded by bottom-mounted PIES. This data serves to investigatethe strength and variability of the NAC crossing 47 /48 N in the NewfoundlandBasin and in the West European Basin3) to analyze the deep water export in the Deep Western Boundary Current (DWBC)across 47 N in the Newfoundland Basin as well as the export of Labrador SeaWater (LSW) through Flemish Pass by means of deep-sea moorings and ship2/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017based observations4) to capture the water column properties and identify changes in the components ofNorth Atlantic Deep Water5) to investigate the strength of the NAC from PIES and ship observations as the NACcrosses the Mid-Atlantic Ridge and enters the eastern basin.Due to the echo-sounder calibration and sea acceptance test added to cruise MSM-64, thecruise was longer than originally scheduled, but the available time to pursue the originalscientific program of cruise MSM-64 needed to be shortened. As further time was lost inthe eastern basin due to bad weather, the section along the western flank of the MidAtlantic Ridge could not be carried out, and thus objective 5 could not be met.Scientific tools comprised profiling of the entire water column using two lowered AcousticDoppler Current Profilers (LADCP) andaConductivity-Temperature-Depth-Oxygen(CTDO) unit, all attached to a carousel water sampler. Water sampling activities consistedof taking oxygen and salinity samples for the sake of CTDO-sensor calibration as well astaking samples for the analysis of anthropogenic tracers (chlorofluorocarbons) and carbonand oxygen isotopes ratios in seawater. Vessel-mounted ADCP measurements deliveredvelocity data of the upper water column. Seven Argo floats of type NKE ARVOR weredeployed along 47 /48 N and programmed to drift at a parking depth of 1000 dbar and tocycle between 2000 dbar and the sea surface every ten days. Work related to deployingand recovering deep-sea moorings concentrated on the boundary currents at the easternand western continental margins (Goban Spur at the Irish shelf break; eastern flank ofFlemish Cap; Flemish Pass). Telemetry, recovery, and (re-)deployment of inverted echosounders equipped with pressure sensors (PIES) focused on devices installed in the deepbasins along the 47 /48 N section.2. Narrative of cruise MSM-64RV MARIA S. MERIAN left the berth in Southampton, UK, on May 27th, 2017, at 09:30 UTC.When heading towards the southern exit of the English Channel, the scientific mission ofcruise MSM-64 started at 13:24 UTC the same day, when continuous logging of underwaydata was switched on. Course was set towards the Irish shelf break near Porcupine Bank,where a number of test stations were carried in deep and shallow water during May 28 th toMay 31st. These served to check the performance acoustic releases at depth, checks of3/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017the CTDO unit and the two LADCPs attached to the carousel water sampler. Furthermore,the water sample analysis devices were tested. During May 28th to May 31st the twomultibeam echo-sounding devices for shallow and deep water applications were calibratedalong a specific calibration track. Also, the sea acceptance test for the previously newlyinstalled EM-712 multibeam echo-sounder was successfully carried out. On June 02nd, RVMARIA S. MERIAN approached Galway/Ireland and, while lying on the roads in the GalwayBay, we exchanged scientists and technicians. After finishing this exchange, the originalscientific field program of cruise MSM-64 began, and we headed south towards GobanSpur at the Irish shelf break. Between June 03rd and June 09th, we recovered andredeployed mooring EB-1. As the recovery of the two moorings EB-2 and EB-3unfortunately failed, we could only redeploy mooring EB-3. Furthermore, hydrographiccasts including measurements of the oceanic current field were done, and the two easternPIES were exchanged. On June 09th/10th, a severe storm system required interruptingstation work and deviating from the original cruise track. After finishing station work in theWest European Basin, we crossed the Mid-Atlantic Ridge and continued station work inthe Newfoundland Basin. While approaching Flemish Cap, several PIES were recoveredand partly immediately redeployed. Data recorded by the devices over the past year wasretrieved via acoustic telemetry. Hydrographic station work was continued until reachingthe Deep Western Boundary Current east of Flemish Cap. There, we recovered the twomoorings BM-22 and BM-24 on June 17th 2017. Between June 18th and June 21st, wecarried out a densely space CTD section across the western flank of Flemish Cap,reinstalled the remaining PIES in the deep Newfoundland Basin and redeployed themoorings BM-22 and BM-24. On June 21st, we crossed Flemish Cap and continuedhydrographic station work along 47 N in Flemish Pass. On June 22nd, we recovered andsubsequently redeployed mooring BM-25.Continuous logging of underway data was stopped on June 23rd, 17:30 UTC, whichmarked the end of the scientific mission MSM-64 of RV MARIA S. MERIAN. The vesselarrived at the pilot station of St. John's and was finally towed at pier 17 at 19:00 UTC thesame day. In total, 91 hydrographic stations were carried out during cruise MSM-64.Seven Argo floats were deployed. Four deep-sea moorings were recovered, and five wereinstalled again. Seven PIES were recovered, and seven were deployed again, partlyupgraded with an additional currentmeter that turned these devices into C-PIES.4/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017AcknowledgementsWe would like to thank the master of the vessel, Björn Maaß, and his entire crew for theassistance and great support granted to us during the two legs of cruise MSM-64. Theprofessional and constructive cooperation between the different scientific teams and theship’s team, the hospitality experienced onboard the vessel, and the friendly workingenvironment is greatly appreciated.Further thanks go to Barbara Kozak at our home laboratory, the Federal Ministry forEducation and Research (BMBF), the German Research Foundation (DFG), the DFG’sPermanent Senate Commission on Oceanography, and the Control Station GermanResearch Vessels (Leitstelle Deutsche Forschungsschiffe) that provided the necessaryship time, funding, and support to pursue all scientific work.5/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Table 1. Participants of cruise MSM-64NameInstituteField of ActivityLeg1. Kieke, Dagmar, Dr.IUPHB/MARUM chief scientist2. Altona, KarimIUPHB/MARUM sampling of tracers and isotopes23. Buinyi, AlekseiIUPHB/MARUM CTDO/LADCP watch, VMADCPprocessing1 2dos Santos Ferreira,4. Christian1 2MARUMmultibeam calibration15. Frahm, LauraUHHmultibeam calibration16. Garcia Quintana, YarisbelUEACTDO/LADCP watch1 27. Gerken, Jan8. Gerriets, Andrea9. Harbas, TeoIUPHB/MARUM CTDO/LADCP watchLDFBriese2multibeam calibration1superintendent1multibeam calibration110. Herland, AsmundKongsberg11. Köllner, ManuelaBSHmooring analysis1 212. Küper, SveaUHBoxygen analysis2Briesetechnical support113. Meyer, Christian14. Mirau, BastianIUPHB/MARUM moorings15. Nowitzki, HannahIUPHB/MARUM CTDO/LADCP watch, PIES analysis16. Pennelly, ClarkUEACTDO/LADCP watch17. Retsch, MatthiasMPIaerosol measurements18. Roessler, Achim, Dr.19. Schneehorst, Anja20. Steinfeldt, Reiner, Dr.21. Stokland, Gard22. Sültenfuß, Pia23. Uhde, Hans-Hermann24. Wischnewski, FannyIUPHB/MARUM ADCP and PIES data processingBSHmoorings, Argo float deploymentsIUPHB/MARUM CTD/O data processing, calibration,data analysis, salinometryKongsbergmultibeam calibrationIUPHB/MARUM sampling of tracers and isotopesBSHmoorings, Argo float deploymentIUPHB/MARUM CTDO/LADCP watch, LADCPprocessing6/121 221 221 21 21 2121 21 2

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Table 2. Affiliations of cruise participantsInstitutionAffiliationBrieseBriese Schifffahrts GmbH & Co KG, Leer, GermanyBSHFederal Maritime and Hydrographic Agency, Hamburg, GermanyIUPHBUniversity of Bremen, Institute of Environmental Physics,Dep. Oceanography, Bremen, GermanyKongsbergKongsberg Maritime AS, NorwayLDFControl Station German Research Vessels, University of Hamburg,Hamburg, GermanyMARUMUniversity of Bremen, Center for Marine Environmental Sciences, Bremen,GermanyMPIMax Planck Institute for Meteorology, Hamburg, GermanyUEAUniversity of Alberta, Edmonton, Alberta, CanadaUHBUniversity of Bremen, Faculty 2, Biology/Chemistry, Bremen, GermanyUHHUniversity of Hamburg, Institute of Geophysics, Hamburg, GermanyTable 3. Argo float deployments during cruise MSM-64MSMStationFloat s/nWMO IDArgos IDLatitudeLongitudeDeploymentDate/TimeCTD #25-3AL250017DE005 390162417034148 31.081‘N 15 00.066‘W06 Jun.201708:471940-2AL250017DE006 390162517034247 55.889‘N 25 57.218‘W11 Jun.201717:273242-2AL250017DE007 390162617034347 40.048‘N 31 08.665‘W12 Jun 201719:063444-2AL250017DE008 390162717034447 28.879‘N 34 00.899‘W13 Jun 201723:223646-2AL250017DE009 390162817034547 20.053‘N 36 24.371‘W14 Jun 201715:313854-3AL250017DE010 390162917034647 05.296‘N 40 54.534‘W17 Jun 201700:2967-2AL250017DE01117034747 05.649‘N18 Jun 201718:31390163042 37.110‘W4657All times are given as UTC. All deployed floats are of type NKE ARVOR and carry conductivity,temperature, and pressure sensors. The parking depth is 1000 dbar, the cycling period is 10 days.7/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Table 4. Deep-Sea moorings recovered and deployed during cruise EB-1/149 00.02’N12 37.08’W153003 Jun 201713:44 – 15:40–617-1EB-1/249 00.02’N12 37.08’W04 Jun 201715:20 – 16:35610-1EB-2/148 55.02’N13 00.00’W306503 Jun 201717:23 – 17:55mooring lost–-17-1EB-3/148 49.98’N13 25.98’W445303 Jun 201719:42 – 20:11mooring lost–1323-1EB-3/248 49.98’N13 25.98’W4453---05 Jun 201708:31– 15:551357-1BM-22/747 06.19’N43 13.37’W304817 Jun 201714:54 – 17:310–5476-1BM-22/847 06.19’N43 13.37’W3048---21 Jun 201710:57-14:445456-1BM-24/447 06.20’N42 16.50’W400017 Jun 201708:52 – 11:57--4769-1BM-24/547 06.21’N42 16.47’W4008–19 Jun 201710:19-12:155991-1BM-25/447 07.11'N47 06.38'W100322 Jun 201715:18 – 15:57–7891-1BM-25/547 07.11’N47 06.38’W100322 Jun 201718:18 – 18:3278–All times are given as UTC. The top buoy of all deployed moorings was equipped with radiobeacons, flags, flashers, and Iridium or Argos beacons.8/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Table 5. Activities related to inverted echo-sounders with pressure sensors TimeCTD#41BP12/5 271 47 39.91'N 31 08.88'W4090---12 Jun 201719:40 – 22:50---3454BP27/2 302 47 05.75'N 40 53.82'W4503---16 Jun 201718:13 – 21:0216/17 Jun201722:54 –00:264670BP27/3 272 47 05.87’N*------4650BP28/2 240 47 09.72'N 39 29.12'W4591---15 Jun 201719:53 – 22:5115/16 Jun201722:56 –00:404271BP28/3 302 47 10.29’N 39 29.63’W456219 Jun 201722:04–23:43------4248BP29/2 272 47 12.55'N 38 30.95'W4612------15 Jun 201703:41 –05:124048BP29/3 303 47 12.68’N 38 30.93’W460815 Jun 201705:48–07:25------4047BP30/2 235 47 18.06'N 37 21.70'W4539---14 Jun 201719:35 – 22:27---3968BP31/1 075 47 05.84'N 41 59.94'W4236---18 Jun 201720:53 – 01:2268BP31/2 240 47 05.48’N 42 00.38’W421919 Jun 201703:24–04:49------47/5825BP32/1 270 48 31.12'N 15 00.02'W479606 Jun 201701:36 – 02:3306 Jun 201702:39 –04:131925BP32/2 362 48 31.13’N 15 00.22’W479306 Jun 201704:36–05:51------1931BP33/1 268 48 18.50’N 19 31.74’W4560---31BP33/2 363 48 18.66’N 19 31.30’W455308 Jun 201703:48–05:15------2738BP34/1 269 48 06.60’N 23 25.32’W4486---10 Jun 201719:22 – 22:3010/11 Jun201723:04 –00:563138BP34/2 188 48 06.69’N 23 25.16’W448411 Jun 201701:15–02:44------3140 52.54’W19 Jun 20174200**16:2917:40---19 Jun 201747/5801:35 –03:0207/08 Jun 2017 08 Jun 201722:22 – 01:22 01:45 –03:3527All times are given as UTC. All instruments are equipped with flags, radio senders, and flashers.PIES BP-27/3, BP-28/3, BP-29/3, and BP-31/2 were deployed as a C-PIES, i.e., it carried an additional currentmeter of type Nortek Aquadopp and additional buoyancy.9/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017Table 6. List of CTDO/lowered ADCP/water sampling stations carried out during cruise C/18OBottleOxygenLADCP0112017/05/2815:5250 45.47'N11 54.90'W20002005-----0222017/05/2905:5253 33.09'N13 44.21'W250240-----0332017/05/2914:5453 32.62'N13 44.28'W244234-----0442017/05/3012:0953 38.46'N14 58.93'W28742870-----0552017/05/3105:5253 38.54'N14 58.64'W28782871----x0662017/06/0310:2449 00.69'N12 35.72'W14741473----x1172017/06/0318:1748 50.06'N13 5217:0019:3723:0802:1017:3449 14.16'N49 11.06'N49 07.85'N49 04.76'N49 01.61'N48 59.67'N48 56.88'N48 53.77'N48 50.62'N48 50.00'N48 44.91'N11 26.77'W11 41.74'W11 56.55'W12 11.50'W12 26.43'W12 38.62'W12 48.82'W13 03.79'W13 18.60'W13 26.02'W13 xxxxxxxxxxxxxxxxx25192017/06/0605:5648 31.07'N14 59.99'W48004799x-xxx26202017/06/0611:0348 35.51'N14 33.23'W46984685---xx10/12Commentstest of acoustic releases; depthtest of Iridium and radio beacons;lADCP failure; substandard forsalinometrytest of acoustic releases; depthtest of Iridium and radio beacons;lADCP failuredepth test of Argos beacons;llADCP failuretest of acoustic release, s/n 2263;calibration stops for NKE loggers& MicroCATs; lADCP failuretest of several acoustic releases;calibration stops for Seaguardscalibration stops for Seaguards &MicroCATsArgo float deployment, WMO-ID3901624

5446555859474849Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 20172017/06/06 19:1148 28.26'N15 38.62'W48404831xxx2017/06/07 00:4548 26.71'N16 17.26'W46704694xx2017/06/07 06:3048 25.14'N16 55.91'W46804670xxxxdepth test of radio beacon, s/n2017/06/07 12:0548 23.58'N17 34.50'W42054186xxV01-0242017/06/08 10:0148 21.96'N18 13.20'W44504441xxx2017/06/08 16:0448 20.38'N18 51.88'W42324223xx2017/06/08 21:2648 18.59'N19 31.34'W45624551xxxx2017/06/09 03:1248 16.24'N20 09.32'W44334421xx2017/06/09 09:0948 13.78'N20 47.73'W43614346xxx2017/06/09 14:2848 11.46'N21 26.26'W44604438xx2017/06/11 02:5148 06.65'N23 24.96'W45024486xxxxtest of acoustic release, s/n 761;depth test of radio beacon, s/n2017/06/11 15:3547 55.90'N25 57.21'W28432826xxxxV09-044; Argo float deployment,WMO-ID 39016252017/06/12 03:3947 47.81'N28 32.57'W32533237xxxxcalibration stops for Aquadopps,2017/06/12 16:0047 39.95'N31 08.81'W40944075xxxxArgo float deployment, WMO-ID39016262017/06/13 08:4547 34.46'N32 34.72'W39643949xxxxArgo float deployment, WMO-ID2017/06/13 20:2747 29.05'N34 00.77'W47304716xxxx39016272017/06/14 06:2347 23.67'N35 26.92'W43204305xxxxArgo float deployment, WMO-ID2017/06/14 12:4847 20.10'N36 24.31'W42444228xxx39016282017/06/14 19:0347 18.10'N37 21.69'W45404531xxxx2017/06/15 07:3047 12.45'N38 31.20'W46184608xxxx2017/06/15 12:0747 10.25'N39 01.24'W45934582xx2017/06/15 16:3747 09.77'N39 29.10'W45994578xxxx2017/06/16 02:0747 08.21'N39 50.17'W45934559xx2017/06/16 06:3947 06.58'N40 11.28'W45604557xxx2017/06/16 10:4847 06.14'N40 32.54'W45304542xxArgo float deployment, WMO-ID2017/06/16 15:0747 05.75'N40 53.70'W44984483xxxx39016292017/06/17 04:2347 05.81'N41 59.88'W42184209xxxx2017/06/17 20:2147 06.06'N44 02.56'W357346xxx2017/06/17 21:4547 05.98'N43 47.49'W580573xxx11/12

7172737475767778Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 20172017/06/17 22:5647 06.02'N43 38.41'W768753xxx2017/06/18 00:3747 05.99'N43 25.27'W12801265xxxx2017/06/18 02:0047 05.90'N43 20.17'W17971761xxx2017/06/18 03:3347 06.03'N43 17.83'W25562551xxx2017/06/18 05:3247 06.20'N43 13.26'W30403027xxxx2017/06/18 08:0547 06.05'N43 07.14'W34973504xxx2017/06/18 11:1347 06.04'N42 53.60'W34603444xxxcalibration stops for MicroCATstest of acoustic releases, s/n761 798; calibration stops for2017/06/18 15:1547 06.02'N42 35.42'W36683646xxxMicroCATs; Argo float deployment,WMO-ID 39016302017/06/18 21:0647 05.83'N41 59.80'W42244206xtest of acoustic release, s/n 7982017/06/19 05:5747 06.19'N42 16.50'W40003986xxx2017/06/20 04:4747 15.79'N37 45.39'W45194535xxxxtest of acoustic release, s/n 798 2017/06/20 08:5447 14.01'N38 07.98'W45004533xxx8102017/06/20 23:1047 06.18'N41 16.87'W44394404xxx2017/06/21 03:0747 06.20'N41 39.41'W43054273xxx2017/06/21 23:5347 06.05'N46 08.37'W330320xx2017/06/22 01:1547 06.02'N46 24.15'W350343x2017/06/22 02:2047 06.05'N46 33.23'W490477xxx2017/06/22 03:0847 06.03'N46 36.61'W800791xxx2017/06/22 04:0547 06.04'N46 40.02'W10991085x2017/06/22 05:0947 06.02'N46 42.46'W11361124xxx2017/06/22 06:3047 06.03'N46 51.21'W11701154xx2017/06/22 07:5747 06.08'N47 00.58'W11301113xxx2017/06/22 09:0747 05.96'N47 05.87'W10241008xx2017/06/22 10:1647 05.99'N47 09.34'W880866xxx2017/06/22 11:2047 06.02'N47 12.47'W728716xx2017/06/22 12:1847 05.96'N47 15.85'W475462xxx2017/06/22 13:1147 05.79'N47 19.45'W306293x2017/06/22 13:5847 05.80'N47 22.83'W240229x2017/06/22 16:0847 06.98'N47 06.05'W1010998x12/12

Short Cruise Report, RV Maria S. Merian, Cruise MSM-64, Southampton – Galway – St. John's, 27 May – 23 Jun 2017. 1. Objectives. Physical oceanographic measurements conducted during cruise MSM-64 contributed to the scientific project RACE-II (“Regional Atlantic ChangE”), sub-project 1.2, funded