CRUISE REPORT: P06W (Updated MAR 2018) Highlights Cruise Summary Information Section Designation: P06W Expedition designation (ExpoCodes): 320620170703 Chief Scientists: Sabine Mecking Isabella Rosso (Co-Chief) Dates: 2017-JUL-03 to 2017-AUG-17 Ship: Nathaniel B Palmer Ports of call: Sydney, Australia to Papeete, Tahiti -30.0786 Geographic Boundaries: 153.4799 -148.9082 -32.5015 Stations: 144 Floats and drifters deployed: 8 Argo/O2 floats, 2 SOCCOM floats, 14 drifters Moorings deployed or recovered: 0 Contact Information: Sabine Mecking Email: smecking@apl.washington.edu โ€ข Phone: 206-221-6570 Isabella Rosso irosso@ucsd.edu Cruise Report of the 2017 P06W US GO-SHIP Reoccupation Release Draft 1 Sabine Mecking Nov 20, 2017 TABLE OF CONTENTS 1 GO-SHIP P06W 2017 Hydrographic Program . . . . . . . . . . . . . . . . . . . . 5 1.1 Programs and Principal Investigators . . . . . . . . . . . . . . . . . . . 5 1.2 Science Team and Responsibilities . . . . . . . . . . . . . . . . . . . . . 6 1.3 Underwater Sampling Package . . . . . . . . . . . . . . . . . . . . . . . . 7 2 Cruise Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2 Cruise Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.3 Preliminary results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.4 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3 CTDO and Hydrographic Analysis . . . . . . . . . . . . . . . . . . . . . . . . 14 3.1 CTDO and Bottle Data Acquisition . . . . . . . . . . . . . . . . . . . . . 14 3.2 CTDO Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.3 Pressure Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.4 Temperature Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.5 Conductivity Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.6 CTD Dissolved Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4 Salinity . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 22 4.1 Equipment and Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.2 Sampling and Data Processing . . . . . . . . . . . . . . . . . . . . . . . 23 4.3 Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 5 Nutrients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 5.1 Summary of Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 5.2 Equipment and Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 24 5.3 Nitrate/Nitrite Analysis . . . . . . . . . . . . . . . . . . . . . . . . . 24 5.4 Phosphate Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.5 Silicate Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.6 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.7 Data Collection and Processing . . . . . . . . . . . . . . . . . . . . . . 26 5.8 Standards and Glassware Calibration . . . . . . . . . . . . . . . . . . . . 26 5.9 Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.10 Analytical Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 6 Oxygen Analysis . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 29 6.1 Equipment and Techniques . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.2 Sampling and Data Processing . . . . . . . . . . . . . . . . . . . . . . . 30 6.3 Volumetric Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.4 Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 6.5 Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 7 Total Alkalinity . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . 32 7.1 Total Alkalinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.2 Total Alkalinity Measurement System . . . . . . . . . . . . . . . . . . . . 32 7.3 Sample Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.4 Problems and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . 33 7.5 Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 8 Dissolved Inorganic Carbon (DIC) . . . . . . . . . . . .. . . . . . . . . . . . 34 8.1 Sample collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 8.2 Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.3 DIC Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.4 DIC Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.5 Calibration, Accuracy, and Precision . . . . . . . . . . . . . . . . . . . 36 8.6 Underway DIC Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 8.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 9 Discrete pH Analyses (Total Scale) . . . . . . . . . . . .. . . . . . . . . . . 38 9.1 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9.2 Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9.3 Reagents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 9.4 Data Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 9.5 Problems and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . 39 9.6 Standardization/Results . . . . . . . . . . . . . . . . . . . . . . . . . . 40 10 CFC-11, CFC-12, CFC-113, and SF6 . . . . . . . . . . . .. . . . . . . . . . . 41 10.1 Sample Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 10.2 Equipment and Technique . . . . . . . . . . . . . . . . . . . . . . . . . 41 10.3 Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 11 Dissolved Organic Phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . 42 12 Nitrate ๐›ฟ15N and ๐›ฟ18O . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 13 Dissolved Organic Carbon and Total Dissolved Nitrogen . . . . . . . . . . . . 44 13.1 Project Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 13.2 Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 13.3 Standard Operating Procedure for DOC Analyses- Carlson Lab UCSB . . . . . 44 13.4 DOC calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 13.5 Standard Operating Procedure for TDN analyses- Carlson Lab UCSB . . . . . 45 13.6 TDN calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 14 Carbon Isotopes in seawater (14/13C) . . . . . . . . . . . . . . . . . . . . . 46 15 LADCP . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . 47 15.1 LADCP system configuration . . . . . . . . . . . . . . . . . . . . . . . 47 15.2 Problems/Setup changes . . . . . . . . . . . . . . . . . . . . . . . . . 48 15.3 Data Processing and Quality Control . . . . . . . . . . . . . . . . . . . 49 16 Chipods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 16.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 16.2 System Configuration and Sampling . . . . . . . . . . . . . . . . . . . . 50 16.3 Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 17 Float Deployments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 17.1 SOCCOM floats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 17.2 SIO floats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 17.3 UW floats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 18 Drifter Deployments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 19 Student Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 19.1 Rebecca L. Beadling . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 19.2 Maxime Duchet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 19.3 Kimberly Gottschalk . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 19.4 Ratnaksha Lele . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 19.5 Kelly McCabe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 19.6 Natalie Zielinski . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 CCHDO Data Processing Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 1 GO-SHIP P06W 2017 HYDROGRAPHIC PROGRAM [image]Cruise track of P06W The Pacific Ocean P06W repeat hydrographic line was reoccupied for the US Global Ocean Carbon and Repeat Hydrography Program. Reoccupation of the P06W transect occurred on the RVIB Nathaniel B Palmer from July 3, 2017 to August 17, 2017. The survey of P06W consisted of *CTDO*, rosette, *LADCP*, chipod, water samples and underway measurements. The ship departed from the port of Sydney, Australia and completed the cruise in the port of Papeete on the island of Tahiti, French Polynesia. A total of 144 stations were occupied with one CTDO/rosette/LADCP/chipod package. 144 stations and 150 CTDO/rosette/LADCP/chipod casts including 2 test casts were performed. The stations were, for the most part, a reoccupation of P06W-2009 and detailed in the following sections. 8 Argo/O2 floats were deployed on I09N and detailed in the Argo section of the cruise report. 2 *SOCCOM* floats were deployed on P06W and are detailed in the SOCCOM section of the cruise report. X drifters were deployed on P06W and are detailed in the drifter section of the cruise report. [image]Distrubtion of samples by longitude. [image]Distribution of samples by station number. CTDO data and water samples were collected on each CTDO, rosette, LADCP, and chipod cast, usually within 10 meters of the bottom. Water samples were measured on board for salinity, dissolved oxygen, nutrients, *DIC*, pH, total alkalinity and *CFCs*/*SF6*. Additional water samples were collected and stored for shore analyses of Nitrate ฮ”15N and ฮ”18O, *DOC*/*TDN*, 13C/14C, *POC*, *HPLC*, DOP and DON. A sea-going science team assembled from 13 different institutions participated in the collection and analysis of this data set. The programs, principal investigators, science team, responsibilities, instrumentation, analysis and analytical methods are outlined in the following cruise document. 1.1 Programs and Principal Investigators Principal Program Affiliation Investigator Email โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” *CTDO* Data, Salinity, *UCSD*, *SIO* Susan Becker, sbecker@ucsd.edu Nutrients, Dissolved O2 Jim Swift jswift@ucsd.edu ----------------------- --------------- ----------------- -------------------------- Total CO2 (DIC) *PMEL*, *AOML*, Richard Feely, Richard.A.Feely@noaa.gov *NOAA* Rik Wanninkhof Rik.Wanninkhof@noaa.gov ----------------------- --------------- ----------------- -------------------------- Underway Temperature, *AOML*, *NOAA*, Rik Wanninkhof, Rik.Wanninkhof@noaa.gov, Salinity, and pCO2 *ASC* *ASC* admin@nbp.usap.gov ----------------------- --------------- ----------------- -------------------------- Total Alkalinity, pH *UCSD*, *SIO* Andrew Dickson adickson@ucsd.edu ----------------------- --------------- ----------------- -------------------------- ADCP *UH* Eric Firing efiring@soest.hawaii.edu ----------------------- --------------- ----------------- -------------------------- *LADCP* *LDEO* Andreas Thurnherr ant@ldeo.columbia.edu ----------------------- --------------- ----------------- -------------------------- *CFCs*, *SF6* *U Miami*, *UT* Rana Fine, rfine@rsmas.miami.edu, Dong-Ha Min dongha@mail.utexas.edu ----------------------- --------------- ----------------- -------------------------- *DOC*, *TDN* *UCSB* Craig Carlson carlson@lifesci.ucsb.edu ----------------------- --------------- ----------------- -------------------------- C13 & C14 *WHOI*, Ann McNichol, amcnichol@whoi.edu, *Princeton* Robert Key key@princeton.edu ----------------------- --------------- ----------------- -------------------------- Transmissometry *TAMU* Wilf Gardner wgardner@ocean.tamu.edu ----------------------- --------------- ----------------- -------------------------- Fluorescence and *U Maine* Emmanuel Boss emmanuel.boss@maine.edu Backscatter (*SOCCOM*), HPLC & POC ----------------------- --------------- ----------------- -------------------------- Chipod *OSU* Jonathan Nash nash@coas.oregonstate.edu ----------------------- --------------- ----------------- -------------------------- Nitrate ฮด15N and ฮด18O *Princeton* Daniel Sigman sigman@princeton.edu ----------------------- --------------- ----------------- -------------------------- DON and DOP *FSU* Angela Knapp anknapp@fsu.edu ----------------------- --------------- ----------------- -------------------------- Argo Floats *UW*, Steve Riser, riser@ocean.washington.edu *UCSD*, *SIO* Dean Roemmich, droemmich@ucsd.edu, John Gilson jegilson@gmail.com ----------------------- --------------- ----------------- -------------------------- *SOCCOM* Floats *UW*, Steve Riser, riser@ocean.washington.edu *UCSD*, *SIO* Lynne Talley ltalley@ucsd.edu ----------------------- --------------- ----------------- -------------------------- Surface Drifters *NOAA*, *AOML* Shaun Dolk Shaun.dolk@noaa.gov ----------------------- --------------- ----------------- -------------------------- Underway Bathymetry and *ASC* *ASC* admin@nbp.usap.gov Meteorological Data 1.2 Science Team and Responsibilities Duty Name Affiliation Email Address โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” Chief Scientist Sabine Mecking *UW*-*APL* mecking@uw.edu --------------------- ------------------- ------------ ----------------------------- Co-Chief Scientist, Isabella Rosso *UCSD* irosso@ucsd.edu floats and drifters --------------------- ------------------- ------------ ----------------------------- CTD Watchstander Kimberly Gottschalk *UW* kgotts@uw.edu --------------------- ------------------- ------------ ----------------------------- CTD Watchstander Maxime Duchet *ENSTA* maxime.duchet@ensta- paristech.fr --------------------- ------------------- ------------ ----------------------------- CTD Watchstander, Ratnaksha Lele *UCSD* rlele@ucsd.edu Chipods --------------------- ------------------- ------------ ----------------------------- CTD Watchstander Rebecca Beadling *UA* beadling@email.arizona.edu --------------------- ------------------- ------------ ----------------------------- CTD Watchstander, Natalie Zielinski *TAMU* njzielinski@tamu.edu LADCP --------------------- ------------------- ------------ ----------------------------- Nutrients, *ODF* Susan Becker *UCSD* *ODF* sbecker@ucsd.edu supervisor, *SOCCOM* floats --------------------- ------------------- ------------ ----------------------------- Nutrients David Cervantes *UCSD* *ODF* d1cervantes@ucsd.edu --------------------- ------------------- ------------ ----------------------------- CTDO Processing, Joseph Gum *UCSD* *ODF* jgum@ucsd.edu Database Management --------------------- ------------------- ------------ ----------------------------- Salts, ET John Calderwood *UCSD* *SEG* jcalderwood@ucsd.edu --------------------- ------------------- ------------ ----------------------------- Salts Kelsey Vogel *UCSD* *STS* kdvogel@ucsd.edu --------------------- ------------------- ------------ ----------------------------- Dissolved O2, Data- Andrew Barna *UCSD* *ODF* abarna@ucsd.edu base Management --------------------- ------------------- ------------ ----------------------------- Dissolved O2, Data- Courtney Schatzman *UCSD* *ODF* cschatzman@ucsd.edu base Support --------------------- ------------------- ------------ ----------------------------- SADCP, *LADCP* Alma Carolina *UH* acast@hawaii.edu Castillo-Trujillo --------------------- ------------------- ------------ ----------------------------- *DIC*, underway pCO2 Charles *AOML* charles.featherstone@noaa.gov Featherstone --------------------- ------------------- ------------ ----------------------------- *DIC* Andrew Collins *PMEL* andrew.collins@noaa.gov --------------------- ------------------- ------------ ----------------------------- *CFCs*, SF6 Jim Happell *U Miami* jhappell@miami.edu --------------------- ------------------- ------------ ----------------------------- *CFCs*, SF6 David Cooper davidcooper59@gmail.com --------------------- ------------------- ------------ ----------------------------- *CFCs*, SF6 student Kelly McCabe *FSU* kmm12c@my.fsu.edu --------------------- ------------------- ------------ ----------------------------- Total Alkalinity Manuel Belmonte *UCSD* manbelmonte1@gmail.com --------------------- ------------------- ------------ ----------------------------- Total Alkalinity Derek Smith *UCSD* dereksmith50@gmail.com --------------------- ------------------- ------------ ----------------------------- pH Stephanie Mumma *UCSD* smumma@ucsd.edu --------------------- ------------------- ------------ ----------------------------- *DOC*, *TDN*, Radio Chance English *UCSB* cje@umail.ucsb.edu Carbon --------------------- ------------------- ------------ ----------------------------- Marine Projects Eric Hutt *ASC* mpc@nbp.usap.gov Coordinator --------------------- ------------------- ------------ ----------------------------- Marine Lab Technician John Betz *ASC* mlt@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Marine Technician Jennie Mowatt *ASC* mt@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Marine Technician Michael Tepper- *ASC* mt@nbp.usap.gov Rassmusen --------------------- ------------------- ------------ ----------------------------- Marine Technician Paul Savoy *ASC* mt@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Electronic Technician Barry Bjork *ASC* et@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Electronic Technician George Aukon *ASC* et@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Network Administrator Sean Drabant *ASC* admin@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- Network Administrator Matt Pullen *ASC* admin@nbp.usap.gov --------------------- ------------------- ------------ ----------------------------- 1.3 Underwater Sampling Package CTDO/rosette/LADCP/chipod casts were performed with a package consisting of a 36 bottle rosette frame, a 36-place carousel and 36 Bullister style niskin bottles with an absolute volume of 10.6L. Underwater electronic components primarily consisted of a SeaBird Electronics pressure sensor and housing unit with dual exhaust, dual pumps, dual temperature, a reference temperature, dual conductivity, dissolved oxygen, transmissometer, chlorophyll fluorometer and backscatter meter, oxygen optode, and altimeter. LADCP and chipods instruments were deployed with the CTD/rosette package and their use is outlined in sections of this document specific to their titled analysis. CTD and cage were vertically mounted at the bottom of the rosette frame, located below the carousel for all stations. The temperature, conductivity, dissolved oxygen, respective pumps and exhaust tubing was mounted to the CTD and cage housing as recommended by SBE. The reference temperature sensor was mounted between the primary and secondary temperature sensors at the same level as the intake tubes for the exhaust lines. The transmissometer was mounted horizontally. The fluorometer, oxygen optode, and altimeters were mounted vertically inside the bottom ring of the rosette frames. The 150 KHz bi- directional Broadband LADCP (RDI) unit was mounted vertically on the bottom side of the frame. The 300 KHz bi-directional Broadband LADCP (RDI) unit was mounted vertically on the top side of the frame. The LADCP battery pack was also mounted on the bottom of the frame. Equipment Model S/N Cal Date Stations Responsible Party โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” Rosette 36-place Yellow _ 1-143 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- CTD SBE9+ 1281 _ 1-143 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Pressure Sensor Digiquartz 136428 Apr 10, 2017 1-143 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE3+ 35844 Apr 11, 2017 1-143 *STS*/*ODF* Temperature ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE4C 42569 Sep 20, 2016 1-116 *STS*/*ODF* Conductivity ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE4C 43399 Apr 7, 2017 117-143 *STS*/*ODF* Conductivity ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary Pump SBE5 54890 _ 1-7 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary Pump SBE5 51646 _ 8-143 *ASC* ---------------- --------------- ------------ ------------ ---------------- ----------------- Secondary SBE3+ 32309 Apr 18, 2017 1-143 *STS*/*ODF* Temperature ---------------- --------------- ------------ ------------ ---------------- ----------------- Secondary SBE4C 42819 Apr 11, 2017 1-143 *STS*/*ODF* Conductivity ---------------- --------------- ------------ ------------ ---------------- ----------------- Secondary Pump SBE5 54377 _ 1-10 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Secondary Pump SBE5 55644 _ 10-143 *ASC* ---------------- --------------- ------------ ------------ ---------------- ----------------- Transmissometer Cstar CST-1803DR Sep 16, 2016 1-143 *TAMU* ---------------- --------------- ------------ ------------ ---------------- ----------------- Fluorometer WetLabs FLBBRTD-3698 Sep 23, 2014 1-143 *U Maine* Chlorophyll and Backscatter ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE43 430255 Apr 7, 2017 901-902, 105-143 TS*/*ODF* Dissolved Oxygen ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE43 431136 Apr 11, 2017 1-73 TS*/*ODF* Dissolved Oxygen ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE43 430275 Mar 30, 2017 74-76 TS*/*ODF* Dissolved Oxygen ---------------- --------------- ------------ ------------ ---------------- ----------------- Primary SBE43 430080 Feb 4, 2017 77-143 *ASC* Dissolved Oxygen ---------------- --------------- ------------ ------------ ---------------- ----------------- Oxygen Optode RINKO 0251 Dec 21, 2015 1-143 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Reference SBE35 0035 Apr 13, 2017 1-143 *STS*/*ODF* Temperature ---------------- --------------- ------------ ------------ ---------------- ----------------- Carousel SBE32 0187 _ 1-12 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Carousel SBE32 1178 _ 13-143 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Altimeter Tritech LPA200 _ _ 901, 4-5, 7 *STS*/*ODF* ---------------- --------------- ------------ ------------ ---------------- ----------------- Altimeter Benthos PSA-916 _ _ 901-3, 6 *ASC* ---------------- --------------- ------------ ------------ ---------------- ----------------- Altimeter Valeport 500 _ _ 8-143 *ASC* The DUSH5 baltic room winch deployment system was successfully used for all stations. The rosette system was suspended from a UNOLS- standard three-conductor 0.322" electro-mechanical sea cable. The sea cable was terminated at the beginning of P06W-2017. An electrical and mechanical termination was completed after station/cast 106/01 due to a small kink in the wire. The deck watch prepared the rosette 10-30 minutes prior to each cast. The bottles were cocked and all valves, vents and lanyards were checked for proper orientation. LADCP technician would check for LADCP battery charge, prepare instrument for data acquisition and disconnect cables. The chipod battery was monitored for charge and connectors were checked for fouling and connectivity. Every 20 stations, the transmissometer windows were cleaned and an on deck blocked and un- blocked voltage readings were recorded prior to the cast. Once stopped on station, the Marine Technician would check the sea state prior to cast and decide if conditions were acceptable for deployment. Recovering the package at the end of the deployment was essentially the reverse of launching. The rosette, CTD and carousel were rinsed with fresh water frequently. CTD maintenance included flushing fresh water through both plumbed sensor lines between casts. The rosette was routinely examined for valves and o-rings leaks, which were maintained as needed. Some complications were overcome to complete CTDO/rosette/LADCP/chipod station casts for I09N. Mounting sea state due to storms caused two kinks in the wire on different stations shortly after retermination on station/cast 106/01. The kinks were inspected for severity, bent back into shape, and then redeployed without retermination. The storms caused casts to proceed slower than normal, limiting deployment speed to 20 meters per minute for the first 1000 meters on some stations during storms. 2 CRUISE NARRATIVE 2.1 Summary A hydrographic survey (P06, leg 1) was conducted in the South Pacific Ocean from 3 July - 17 August 2017 aboard the RVIB Nathaniel B. Palmer. The icebreaker belongs to Edison Chouest Offshore (ECO) and is operated by NSFโ€™s U.S. Antarctic Program (USAP) via a contract with the Antarctic Support Contractors (ASC). A total of 143 CTD rosette casts were occupied on a transect running along 32.50ยฐS (30.08ยฐS at the beginning off the Australian Coast) from 153.48ยฐE to 148.91ยฐW with port calls in Sydney, Australia and Papeete, French Polynesia at the beginning and the end of the cruise, respectively. CTD casts extended to within about 10 meters of the seafloor, and up to 36 water samples were collected in Niskin bottles (with Bullister modifications) throughout the water column on all casts. In addition to the CTD (conductivity, temperature, depth/pressure) sensors, two oxygen (O) sensors, upward and downward looking LADCPs (lowered acoustic Doppler current profilers), a transmissometer, a fluorometer (including backscatter sensor), and an altimeter were mounted onto the rosette frame. In addition, 4 UW Argo floats, 2 SIO SOLO floats, 3 SIO Deep SOLO floats, 2 SOCCOM floats, and 14 drifters were deployed on the 2017 P06, leg 1 occupation. Salinity and dissolved oxygen samples, drawn from all Niskin bottles that were closed on each cast, were analyzed and used to calibrate the CTDO conductivity and oxygen sensors. Water samples were also analyzed onboard the ship for nutrients (nitrate, nitrite, phosphate, silicate), total CO2/TCO2 (aka dissolved inorganic carbon/DIC), pH, total alkalinity, and transient tracers (chlorofluorocarbons/CFCs and sulfur hexafluoride/SF6). Additional samples were collected for onshore analysis: radiocarbon ฮด13C/ฮด14C), dissolved organic carbon (DOC), dissolved organic phosphorus (DOP), nitrogen and oxygen isotopes of nitrate ฮด15N, ฮ”18O), phytoplankton pigment using high performance liquid chromatography (HPLC), and particulate organic carbon (POC). Underway measurements included GPS navigation, multibeam and Knudsen bathymetry, ADCP, meteorological parameters, and sea surface measurements (including temperature, conductivity/salinity, dissolved oxygen, fluorescence, and pCO2) and gravity. 2.2 Cruise Narrative The GO-SHIP 2017 P06 repeat hydrography cruise across the South Pacific subtropical gyre is a repeat of earlier section occupations that were conducted in 1992 as part of the U.S. WOCE program, in 2003 as part of the Japanese BEAGLE cruises, and in 2009/2010 as part of the U.S. CLIVAR/CO2 Repeat Hydrography program. Goals of the repeat sections include the monitoring of oceanic inventories of CO2, heat, and freshwater, examination of changes in ocean transports and ventilation fluxes, and combining observations of a plethora of oceanic properties with global models, for a better prediction of the future state of the ocean and the atmosphere. Mobilization for leg 1 of the P06 cruise began in Sydney on 28 June (all dates are local times/dates) when most of the science gear was loaded onto the RVIB Nathaniel B. Palmer (NBP), docked in the White Bay section (terminal 4) of Sydney Harbor. Only the ODF van and some missing sample bottles were left for loading on 29 June. All the measurement groups started setting up in the labs, running tests, and trouble-shooting as soon as their items were on board. The NBP left Sydney on 3 July at 10:00am with 24 science party members from seven countries on board (plus the ASC and ECO crews), heading north to the first station of leg 1. Along the way, on the morning of 4 July, a test station was conducted in Australian waters (as permitted by the clearance request) at ~31.5S, 153.5E, in about 3830m of water. In order to test the equipment and to give both watches practice with the CTD console procedures, two casts were performed. The first cast went to a depth of 100m without any bottles fired. On the second cast, the rosette was lowered to 2000m, and all 36 bottles were closed at this depth. Measurement groups could choose how many of these bottles to sample for their own test purposes. Based on analysis of test station samples, the CFC group reported elevated SF6 concentrations. Since the rosette was brand new, including the Niskin bottles, the suspicion was that there could be some contamination coming from the bottles. Thus, seven Niskin bottles (first seven odd ones) were exchanged against old ones from the back- up rosette. However, analysis of samples from double-fired bottles at subsequent stations indicated that the bottles were not the issue. Instead, adjustment of flushing times and trap temperatures on the CFC system could fix the SF6 problem. The first "real" station was occupied on the evening of 4 July at 30.09ยฐS, 153.48ยฐE, a few miles off the Australian Coast, in just 84m of water. From there on, the cruise track of P06, leg 1 followed an eastward path across the northern part of the Tasman Basin, the Lord Howe Rise, the New Caledonia Trough and a couple of other ridges and troughs until the South Fiji Basin, with station depths ranging from 100-5100m. During the initial stations, as soon as water depths started becoming deeper, a few more hiccups had to be dealt with. At station 7 (30.08ยฐS, 153.92ยฐE; 2900m), the communication between the LADCP and its console became intermittent until it completely stopped at station 10 (30.08ยฐS, 154.16ยฐE; 4599m). Most cables had been exchanged by then, in order to solve the issue. However, only the removal of the magnetometer, which turned out to be flooded, finally fixed the problem after station 13 (30.08S, 155.49E), and the LADCP operated well for the rest the cruise. First problems with Niskin bottles not closing and mistrips occurred at station 6 (30.08ยฐS, 153.84ยฐE; 1985m). By station 12 (30.08ยฐS, 155.00ยฐE; 4707m), seven bottles stayed open despite confirmation on the console that they had been fired. Even though there were no obvious signs of leaking or deterioration within the pylonโ€™s solenoids, the carousel was exchanged against SIOโ€™s new 36-place pylon (that was meant for the new rosette, but did not arrive in time for assembly) right after station 12. The new carousel functioned pretty much flawlessly for the remainder of the cruise. On departure from station 12, the first float of leg 1, a UW Argo float was deployed, followed by several more floats and drifters throughout the cruise. The cruise track diverted slightly to the south for station 26 (30.33ยฐS, 158.08ยฐS) to maintain sufficient distance to the Elizabeth Reef. After that, stations continued along 30.08ยฐS. Within the South Fiji Basin, after station 76 at 30.08ยฐS, 176.50ยฐE, the cruise track deflected to the southeast, until station 82 at 32.50ยฐS, 178.91ยฐE. From station 82 onward, the cruise track continued straight eastward again along the 32.50ยฐS latitude band. This change in latitude from 30.08ยฐS to 32.50ยฐS occurs on all P06 occupations and is dictated by moored current meter arrays that were deployed during the time of WOCE, just poleward of 30ยฐS within the East Australia Current (off Australia) and along 32.50ยฐS within the deep western boundary current (DWBC) region, east of the Tonga Kermadec Ridge (TKR, ~179ยฐW) (WOCE PCM9 array). One of the goals of the P06 WOCE occupation in 1992 was to perform hydrographic surveys along these arrays. Within the South Fiji Basin, we also encountered the first seriously bad weather that interrupted operations on 20 July, after station 76. Wind gusts of >50 knots meant that the NBP could not hold station. Station 77 (30.53ยฐS, 176.94ยฐE) could not be deployed until the next day (21 July) in the afternoon. After that, operations were stopped again through the night. By the morning of 22 July, waves were even higher. We were also informed that a medevac was necessary for one of the ECO crew members. What followed was a bumpy ride to New Zealand, with wave heights at 6-8m and some even bigger rollers, and evacuation of the ill seaman by helicopter, about 100nm north of New Zealand. By 10:00am on 23 July, we were back on our way to the South Fiji Basin. Station 78 at 30.98ยฐS, 177.40ยฐE was finally occupied at 6am on 24 July. A total of ~3.5 days of station time had been lost due to weather and medevac at this point. With several days of delay, we crossed the Lau Basin on 25 July, including the International Dateline at ~11:30pm. The corresponding set-back of clocks by a day gave us the opportunity to enjoy a "full 48 hours of Tuesday, July 25" (the Captain's words). After the Lau Basin and the adjacent TKR (to the east), followed the crossing of the DWBC and its recirculation between the TKR and Louisville Seamount Chain at ~188.2ยฐW. The eastern flank of the TKR descends into the Kermadec Trench where the deepest stations of P06, leg 1 were encountered. With a maximum depth of 10,047m, the Kermadec Trench is known as the deepest ocean trenches in the world. At stations 93 (32.50ยฐS, 177.67ยฐW) and 94 (32.50S, 176.75W), the trench stations, bottom depth readings from the Knudsen exceeded 7000m. The CTD rosette, however, was only lowered to 6000m depth, because of some of the sensorโ€™s pressure ratings. On the weekend of 20-30 July, just before and during the crossing of the Louisville Seamount Chain, the weather turned rougher again. Operations did not have to be stopped, but wire tension readings were pretty low (double digits) during the descent of the rosette on several stations, despite reduced wire speeds. A kink was noticed in the wire upon recovery at station 106 (32.50ยฐS, 171.12ยฐW). Wire (no loose strands) and electronic transmissions were still intact. However, with more than 100 stations completed, it was about time to re-terminate anyway, and thus it was decided to perform a re- termination. It took about 4 hours, a little bit longer than usual, because new technicians, some staying on for leg 2, were being trained on the procedures. With the stations across the Louisville Seamount Chain pretty close together (8-17nm), the measurements groups were happy to have a little bit of time to catch up again on samples! To the east of the Louisville Seamount Chain began the still very deep (5000-6000m), but flatter stretch of the Southwest Pacific Basin. A particular deep fracture zone was encountered at station 119 (32.50ยฐS, 165.16ยฐW; 6364m) where elevated CFC concentrations had been observed on past cruises and were also found on 2017 P06, leg 1. Because of the time lost earlier in the cruise, it was unfortunately not possible to reduce station spacing around this fracture zone, as originally planned. Bad weather caught up with us again on the evening of 3 August, just after some smooth sailing, reminding us that it was the height of winter in the southern hemisphere after all. A particularly persistent low pressure system hovered to the east of us for pretty much the next four days. Wind speeds gusted >40 knots some of the time, but it was mostly the big and often confused swells that provided problems. Sea states were continuously examined by scientists and ASC staff, and whenever the waves looked reasonable, the CTD rosette was deployed. Two casts had to be aborted and retried later because of continuously low wire tensions and large spikes on the downcast (at station 121, 32.50ยฐS, 163.83ยฐW, and station 126, 32.50ยฐS, 160.46ยฐW). Two more small kinks appeared in the wire after stations 123 and 126, luckily at a safe distance from each other (more than 100 wire diameters). After thorough examination, neither kink was deemed serious enough to warrant another re-termination immediately. During the four days of the storm, only seven stations could be completed (121-127), resulting in about two more days of station time lost due to weather. The option of doing stations slowly, however, was still more efficient than trying to steam eastward past the (large) low pressure system and doing stations in reverse order, as sometimes it is done to escape storms. On 8 August, operations were back to normal, although wire speeds on the down casts often still had to be kept very low (20m/min until 1000-1500m). During the last five days of station work on p06, leg 1, the last SOCCOM float and the last Deep SOLO float, as well as several drifters, were deployed. The last station, station #143 at 32.50ยฐS, 148.91ยฐW, was completed on 13 August early in the morning (5:15am), followed by the last float, a UW Argo float. A "drop dead" time of 5:00am had been given to us by the Captain. Thus, another station, as hoped for to put less burden of leg 1 stations onto leg 2 (4 instead of 5 stations from original station plan), was unfortunately not possible. While there were a lot of delays on this cruise due to weather and the medevac, with a total of about 5.5 days of station time lost, we were happy that we could nevertheless make it just past the longitude of Tahiti (~150ยฐW), our port call between legs 1 and 2. Station spacing at the end of leg 2 was 33.9nm, only slightly up from the 30nm in the original plan. There were also some things that went remarkably well and that helped make up time. The winch in the Baltic room performed pretty much flawlessly, even with 49 of the 143 stations at depths >5000m, allowing for fast station times when the weather was good. There were no communication/data transfer problems with the CTD package, and the new SIO 36-place carousel, once installed, also operated without any further bottle-closing issues. Station positioning, despite the large size of the ship, was pretty speedy most of the time and within the 0.1-minute accuracy (in lat/lon) we had asked from the bridge. The steam speed of the NBP was somewhat faster (>9 knots) than planned for which also helped. In general, station spacing on p06, leg 1 varied between 2.1nm and 38.8nm. 109 stations were at a distance of less than 30nm from the prior station because the cruise crossed a lot of โ€œinteresting topographyโ€ (a quote from the chief scientist, often repeated on the cruise) that required tight station spacing. For the remaining 34 stations, a spacing of 30nm, the typically desired distance between stations on GO-SHIP cruises, or more was used. To make up for time lost due to weather/medevac, station spacing was increased beyond 30nm over flat topography for a few stations in the South Fiji Basin (~36nm; stations 78-80) and in the Southwest Pacific Basin to the east of 169ยฐW for all but one station (stations 114-129, 131-143). In the latter case, the typical spacing was around 34nm. A few stations (stations 127-129) had significantly larger spacing (~38nm), matching the location of three WOCE stations here. An attempt was generally made to match up the 2017 p06 stations with either WOCE or CLIVAR 2009 stations unless the spacing during those earlier programs seemed too large (e.g. east of 158ยฐW). Particular attention was given to the DWBC region between the TKR and Louisville Seamount Chain and a couple of degrees to the east of the seamounts (stations 88-112), where the WOCE PCM9 current meter array had been. Station locations here were kept the same as during WOCE/CLIVAR 2009 except for one station that was added on the western flank of the seamount chain (station 105, 32.50ยฐS, 172.09ยฐE) and two stations further to the west (station 101, 32.50ยฐS, 173.86ยฐE, and station 102, 32.50ยฐS, 173.38ยฐE) that were rearranged to obtain more regular station spacing here. Leg 1 ended in Papeete, Tahiti (~17.5ยฐS, 149.6ยฐE) after an about 960m steam from the last station on the 32.50S transect. The ship arrived early on 17 August, 2017, meeting the pilot boat at about 5:00am and clearing customs by 8:00am. A meeting with the chief and co-chief scientists of leg 2, Kevin Speer and Lena Schulze, had been arranged for 10:00am to hand over all important leg 1 information. After 46 days at sea, we were then able to set foot on land again, to gather for a post-cruise party at the Three Brothers pub, and to explore Tahiti. 2.3 Preliminary results We find that the preliminary salinity and oxygen data collected and processed by ODF show the typical signatures of Antarctic Bottom Water (AABW; low salinity, high oxygen) and Circumpolar Deep Water (CDW; higher salinity, lower oxygen), that have been observed in the DWBC and the adjacent basin on prior P06 occupations. There is a strong CFC signal associated with the DWBC, showing an increase in concentrations compared to 2009. We also observed the typical characteristics of the water masses of the upper ocean, in particular Subantarctic Mode Water (SAMW; low stratification) at about 750m and Antarctic Intermediate Water (AAIW; low salinity) at about 1000m depth. Changes in both bottom/deep water properties and thermocline/intermediate water properties were looked at on board during the cruise and will be the subject of future investigations. 2.4 Acknowledgments There are many thanks to give for a successful completion of P06, leg 1. Jim Swift, Lynne Talley, and Alison Macdonald were essential in organizing the cruise. The GO-SHIP exec committee and PIs gave advice when needed. ODF, under the lead of Susan Becker, provided the brand new rosette and related equipment, and made sure everything was working well on board. We are grateful for the funding provided by NSF and NOAA for the GO-SHIP program. Pre-cruise planning was done in collaboration with ASC (Adam Jenkins and Brad Fabling) who were enjoyable to work with. ASC was also responsible for marine operations while at sea, and we appreciate all the professional support we received from the ASC techs, in particular with the deployment and recovery of the rosette. ECO was in charge of keeping the ship running and did a great job. Meetings with Captain Brandon Bell (ECO) and Marine Projects Coordinator Eric Hutt (ASC) every day at 12:30pm on the bridge to discuss weather and day-to-day operations were fun and productive. All scientists on board worked extremely hard, kept spirits high, and were great to be with. Much thanks to all! 3 CTDO AND HYDROGRAPHIC ANALYSIS PIs * Susan Becker * James Swift Technicians * Joseph Gum 3.1 CTDO and Bottle Data Acquisition The CTD data acquisition system consisted of an SBE-11+ (V2) deck unit and a networked generic PC workstation running Windows 7. SBE SeaSave7 v.7.26.1.8 software was used for data acquisition and to close bottles on the rosette. CTD deployments were initiated by the console watch operators (CWO) after the ship had stopped on station. The watch maintained a CTD Cast logs for each attempted cast containing a description of each deployment event. Once the deck watch had deployed the rosette, the winch operator would lower it to 10 meters. The CTD sensor pumps were configured to start 10 seconds after the primary conductivity cell reports salt water in the cell. The CWO checked the CTD data for proper sensor operation, waited for sensors to stabilize, and instructed the winch operator to bring the package to the surface in good weather or no more than 5 meters in high seas. The winch was then instructed to lower the package to the initial target wire-out at no more than 30m/min to 100m and no more than 60m/min after 100m depending on sea-cable tension and the sea state. The CWO monitored the progress of the deployment and quality of the CTD data through interactive graphics and operational displays. The altimeter channel, CTD pressure, wire-out and center multi-beam depth were all monitored to determine the distance of the package from the bottom. The winch was directed to slow decent rate to 40m/min 100m from the bottom and 20m/min 30m from the bottom. The bottom of the CTD cast was usually to within 10-20 meters of the bottom determined by altimeter data. For each up-cast, the winch operator was directed to stop the winch at up to 36 predetermined sampling pressures. These standard depths were staggered every station using 3 sampling schemes. The CTD CWO waited 30 seconds prior to tripping sample bottles, to ensure package shed wake had dissipated. An additional 15 seconds elapsed before moving to the next consecutive trip depth, which allowed for the SBE35RT to record bottle trip temperature averaged from 14 samples. After the last bottle was closed, the CWO directed winch to recover the rosette. Once the rosette was out of the water and on deck, the CWO terminated the data acquisition, turned off the deck unit and assisted with rosette sampling. Additionally, the watch created a sample log for the deployment which would be later used to record the depths bottles were tripped and correspondence between rosette bottles and analytical samples drawn. Normally the CTD sensors were rinsed after each station using a fresh water tap connected to Tygon tubing. The tubing was left on the CTD between casts, with the temperature and conductivity sensors immersed in fresh water. Each bottle on the rosette had a unique serial number, independent of the bottle position on the rosette. Sampling for specific programs were outlined on sample log sheets prior to cast recovery or at the time of collection. The bottles and rosette were examined before samples were drawn. Any abnormalities were noted on the sample log, stored in the cruise database and reported in the APPENDIX. 3.2 CTDO Data Processing Shipboard CTD data processing was performed after deployment using SIO/ODF python CTD processing software v. 0.1. CTD acquisition data were copied onto a OS X system, and then processed. CTD data at bottle trips were extracted, and a 2-decibar down-cast pressure series created. The pressure series data set was submitted for CTD data distribution after corrections outlined in the following sections were applied. A total of 144 CTD stations were occupied including one test station. A total of 150 CTDO/rosette/LADCP/chipod casts were completed. 144 standard CTDO/rosette/LADCP/chipod casts and one test cast completed with a single 36-place (CTD #1281) rosette was used for all station/casts. CTD data were examined at the completion of each deployment for clean corrected sensor response and any calibration shifts. As bottle salinity and oxygen results became available, they were used to refine shipboard conductivity and oxygen sensor calibrations. Temperature, salinity and dissolved O2 comparisons were made between down and up casts as well as between groups of adjacent deployments. Vertical sections of measured and derived properties from sensor data were checked for consistency. A number of issues were encountered during P06W-2017 that directly impacted CTD analysis. Issues that directly impacted bottle closures, such as slipping guide rings, were detailed in the Underwater Sampling Package section of this report. Temperature, conductivity and oxygen analytical sensor issues are detailed in the following respective sections. 3.3 Pressure Analysis Laboratory calibrations of CTD pressure sensors were performed prior to the cruise. Dates of laboratory calibration are recorded on the underway sampling package table and calibration documents are provided in the APPENDIX. The Paroscientific Digiquartz pressure transducer S/N: 831-99677 was calibrated on November 17th, 2015 at the SIO Calibration Facility. The lab calibration coefficients provided on the calibration report were used to convert frequencies to pressure. Initially SIO pressure lab calibration slope and offsets coefficients were applied to cast data. A shipboard calibration offset was applied to the converted pressures during each cast. These offsets were determined by the pre and post- cast on-deck pressure offsets. The pressure offsets were applied per configuration cast sets. * CTD Serial 1281-99677; Station Set 1 - 143 Start P (dbar) End P (dbar) โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” Min 0.0 -0.1 Max 0.3 0.2 Average 0.2 0.1 Applied Offset 0.1081 An offset of 0.1081 was applied to every cast performed by CTD 1281. On-deck pressure reading for CTD 831 varied from 0.0 to 0.3 dbar before the casts, and -0.1 to 0.2 dbar after the casts. Before and after average difference was 0.2 and 0.1 dbar respectively. The overall average offset before and after cast was 0.1081 dbar. 3.4 Temperature Analysis Laboratory calibrations of temperature sensors were performed prior to the cruise at the SIO Calibration Facility. Dates of laboratory calibration are recorded on the underway sampling package table and calibration documents are provided in the APPENDIX. The pre-cruise laboratory calibration coefficients were used to convert SBE3plus frequencies to ITS-90 temperature. Additional shipboard calibrations were performed to correct sensor bias. Two independent metrics of calibration accuracy were used to determine sensor bias. At each bottle closure, the primary and secondary temperature were compared with each other and with a SBE35RT reference temperature sensor. The SBE35RT Digital Reversing Thermometer is an internally-recording temperature sensor that operates independently of the CTD. The SBE35RT was located equidistant between the two SBE3plus temperature sensors. The SBE35RT is triggered by the SBE32 carousel in response to a bottle closure. According to the manufacturerโ€™s specifications, the typical stability is 0.001ยฐC/year. The SBE35RT was set to internally average over a 15 second period. A functioning SBE3plus sensor typically exhibit a consistent predictable well modeled response. The response model is second order with respect to pressure, a first order with respect to temperature and a first order with respect to time. The functions used to apply shipboard calibrations are as follows. T_{cor} = T + D_1 P_2 + D_2 P + D_3 T_2 + D_4 T + \text{Offset} T_{90} = T + tp_1 P + t_0 T_{90} = T + a P_2 + b P + c T_2 + d T + \text{Offset} Corrected temperature differences are shown in the following figures. [image]SBE35RT-T1 by station (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). [image]Deep SBE35RT-T1 by station (Pressure โ‰ฅ 2000dbar). [image]SBE35RT-T2 by station (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). [image]Deep SBE35RT-T2 by station (Pressure โ‰ฅ 2000dbar). [image]T1-T2 by station (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). [image]Deep T1-T2 by station (Pressure โ‰ฅ 2000dbar). [image]SBE35RT-T1 by pressure (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). [image]SBE35RT-T2 by pressure (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). [image]T1-T2 by pressure (-0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC). The 95% confidence limits for the mean low-gradient (values -0.002ยฐC โ‰ค T1-T2 โ‰ค 0.002ยฐC) differences are ยฑ0.0068ยฐC for SBE35RT-T1, ยฑ0.0067ยฐC for SBE35RT-T2 and ยฑ0.0042ยฐC for T1-T2. The 95% confidence limits for the deep temperature residuals (where pressure โ‰ฅ 2000dbar) are ยฑ0.00086ยฐC for SBE35RT-T1, ยฑ0.0010ยฐC for SBE35RT-T2 and ยฑ0.0008ยฐC for T1-T2. Minor complications impacted the temperature sensor data used for the P06W cruise. โ€ข The SBE35RT was unconfigured at the beginning and set to average and record one sample (one second) per trip. โ€ข This was noticed and fixed to average 14 samples (15 seconds) before station 19. โ€ข The SBE35RT sensor data was not uploaded before cast for stations 7 and 8, with no data reported for those casts. โ€ข The SBE35RT sensor memory was partially full, and there are partial data reported for casts on stations 6 and 12. โ€ข Storms caused tripping on the fly in the upper 100 meters on many stations, leading to some surface SBE35RT averaging periods out of the water. The resulting affected sections of data have been coded and documented in the quality code APPENDIX. 3.5 Conductivity Analysis Laboratory calibrations of conductivity sensors were performed prior to the cruise at the SeaBird Calibration Facility. Dates of laboratory calibration are recorded on the underway sampling package table and calibration documents are provided in the APPENDIX. The pre-cruise laboratory calibration coefficients were used to convert SBE4C frequencies to mS/cm conductivity values. Additional ship-board calibrations were performed to correct sensor bias. Corrections for both pressure and temperature sensors were finalized before analyzing conductivity differences. Two independent metrics of calibration accuracy were examined. At each bottle closure, the primary and secondary conductivity were compared with each other. Each sensor was also compared to conductivity calculated from check sample salinities using CTD pressure and temperature. The differences between primary and secondary temperature sensors were used as filtering criteria to reduce the contamination of conductivity comparisons by package wake. The coherence of this relationship is shown in the following figure. [image]Coherence of conductivity differences as a function of temperature differences. Uncorrected conductivity comparisons are shown in figures Uncorrected CBottle - C1 by station (-0.002 mS/cm BTLCOND-C1 0.002 mS/cm). through Uncorrected C1-C2 by station (-0.002 mS/cm C1-C2 0.002 mS/cm).. [image]Uncorrected C_Bottle - C1 by station (-0.002 mS/cm โ‰ค BTLCOND-C1 โ‰ค 0.002 mS/cm). [image]Uncorrected C_Bottle - C2 by station (-0.002 mS/cm โ‰ค BTLCOND-C2 โ‰ค 0.002 mS/cm). [image]Uncorrected C1-C2 by station (-0.002 mS/cm โ‰ค C1-C2 โ‰ค 0.002 mS/cm). The residual conductivity differences after correction are shown in figures Corrected CBottle - C1 by station (-0.002 mS/cm BTLCOND-C1 0.002 mS/cm). through Corrected C1-C2 by conductivity (-0.002 mS/cm C1-C2 0.002 mS/cm).. [image]Corrected C_Bottle - C1 by station (-0.002 mS/cm โ‰ค BTLCOND-C1 โ‰ค 0.002 mS/cm). [image]Deep Corrected C_Bottle - C1 by station (Pressure >= 2000dbar). [image]Corrected C_Bottle - C2 by station (-0.002 mS/cm โ‰ค BTLCOND-C2 โ‰ค 0.002 mS/cm). [image]Deep Corrected C_Bottle - C2 by station (Pressure >= 2000dbar). [image]Corrected C1-C2 by station (-0.002 mS/cm โ‰ค C1-C2 โ‰ค 0.002 mS/cm). [image]Deep Corrected C1-C2 by station (Pressure >= 2000dbar). [image]Corrected C_Bottle - C1 by pressure (-0.002 mS/cm โ‰ค BTLCOND-C1 โ‰ค 0.002 mS/cm). [image]Corrected C_Bottle - C2 by pressure (-0.002 mS/cm โ‰ค BTLCOND-C2 โ‰ค 0.002 mS/cm). [image]Corrected C1-C2 by pressure (-0.002 mS/cm โ‰ค C1-C2 โ‰ค 0.002 mS/cm). [image]Corrected C_Bottle - C1 by conductivity (-0.002 mS/cm โ‰ค BTLCOND-C1 โ‰ค 0.002 mS/cm). [image]Corrected C_Bottle - C2 by conductivity (-0.002 mS/cm โ‰ค BTLCOND-C2 โ‰ค 0.002 mS/cm). [image]Corrected C1-C2 by conductivity (-0.002 mS/cm โ‰ค C1-C2 โ‰ค 0.002 mS/cm). A functioning SBE4C sensor typically exhibit a predictable modeled response. Offsets for each C sensor were determined using C_Bottle - C_CTD differences in a deeper pressure range (500 or more dbars). After conductivity offsets were applied to all casts, response to pressure, temperature and conductivity were examined for each conductivity sensor. The response model is second order with respect to pressure, second order with respect to temperature, second order with respect to conductivity and a first order with respect to time. The functions used to apply shipboard calibrations are as follows. Corrections made to all conductivity sensors are of the form: C_{cor} = C + cp_2 P^2 + cp_1 P + cc_2 C^2 + cc_1 C + Offset Salinity residuals after applying shipboard P/T/C corrections are summarized in the following figures. Only CTD and bottle salinity data with "acceptable" quality codes are included in the differences. Quality codes and comments are published in the APPENDIX of this report. [image]Salinity residuals by station (-0.002 mPSU โ‰ค SALNTY-C1SAL โ‰ค 0.002 mPSU). [image]Salinity residuals by pressure (-0.002 mPSU โ‰ค SALNTY- C1SAL โ‰ค 0.002 mPSU). [image]Deep Salinity residuals by station (Pressure >= 2000dbar). The 95% confidence limits for the mean low-gradient (values -0.002 mPSU โ‰ค T1-T2 โ‰ค 0.002 mPSU) differences are ยฑ0.0411 mPSU for salinity-C1SAL. The 95% confidence limits for the deep salinity residuals (where pressure โ‰ฅ 2000dbar) are ยฑ0.0028 mPSU for salinity-C1SAL. A number of issues affected conductivity and calculated CTD salinities during this cruise. โ€ข Primary conductivity sensor (S/N: 2569) failed shortly after the bottom of cast 116/01. Inspection after recovery showed goo inside the cell. โ€ข Bottle salinity analysis was complicated due to problems with the two Autosals, leading to knock-on problems when attempting to calibrate conductivity against bottle salinity. โ€ข Salinity lab temperatures were unstable during the time of analysis for stations 134-142. Further details on lab temperature complications are outlined in the Salinity section of this report. The resulting affected sections of data have been coded and documented in the quality code APPENDIX. 3.6 CTD Dissolved Oxygen Laboratory calibrations of the dissolved oxygen sensors were performed prior to the cruise at the SBE calibration facility. Dates of laboratory calibration are recorded on the underway sampling package table and calibration documents are provided in the APPENDIX. The pre-cruise laboratory calibration coefficients were used to convert SBE43 frequencies to ยตmol/kg oxygen values for acquisition only. Additional shipboard fitting were performed to correct for the sensors non-linear response. Corrections for pressure, temperature and conductivity sensors were finalized before analyzing dissolved oxygen data. The SBE43 sensor data were compared to dissolved O2 check samples taken at bottle stops by matching the down cast CTD data to the up cast trip locations along isopycnal surfaces. CTD dissolved O2 was then calculated using Clark Cell MPOD O2 sensor response model for Beckman/SensorMedics and SBE43 dissolved O2 sensors. The residual differences of bottle check value versus CTD dissolved O2 values are minimized by optimizing the SIO DO sensor response model coefficients with a Levenberg-Marquardt non-linear least-squares fitting procedure. The general form of the SIO DO sensor response model equation for Clark cells follows Brown and Morrison [Mill82] and Owens [Owen85] SIO models DO sensor secondary responses with lagged CTD data. In-situ pressure and temperature are filtered to match the sensor responses. Time constants for the pressure response (ฯ„_p), a slow ฯ„_{Tf} and fast ฯ„_{Ts} thermal response, package velocity ฯ„_{dP}, thermal diffusion ฯ„_{dT} and pressure hysteresis ฯ„_h are fitting parameters. Once determined for a given sensor, these time constants typically remain constant for a cruise. The thermal diffusion term is derived by low-pass filtering the difference between the fast response T_s and slow response T_l temperatures. This term is intended to correct non-linearity in sensor response introduced by inappropriate analog thermal compensation. Package velocity is approximated by low- pass filtering 1st-order pressure differences, and is intended to correct flow-dependent response. Dissolved O2 concentration is then calculated: P_h / dO_c dP \ C_2 โ€”โ€”โ€”โ€” | C t + C t + C P + C โ€”โ€”โ€”โ€” + C โ€”โ€”โ€” + C dT | O ml/l = [C ยท V ยท e 5000 + C_3] ยท ฦ’ (T,P)ยทe \ 4 1 4 s 7 l 6 dT 8 dTt 9 / 2 1 DO sat Where: โ€ข O2 ml/l Dissolved O2 concentration in ml/l โ€ข V_DO Raw sensor output โ€ข C_1 Sensor slope โ€ข C_2 Hysteresis ronse coefficient โ€ข C_3 Sensor offset โ€ข f_sat (T , P)|O2| saturation at T,P (ml/l) โ€ข T In-situ temperature (ยฐC) โ€ข P In-situ pressure (decibars) โ€ข P_h Low-pass filtered hysteresis pressure (decibars) โ€ข T_l Long-ronse low-pass filtered temperature (ยฐC) โ€ข T_s Short-ronse low-pass filtered temperature (ยฐC) โ€ข P_l Low-pass filtered pressure (decibars) โ€ข dO_c / dt Sensor current gradient (ยฌยตamps/sec) โ€ข dP/dt Filtered package velocity (db/sec) โ€ข dT Low-pass filtered thermal diffusion estimate (T_s - T_l) โ€ข C_4 - C_9 Ronse coefficients CTD dissolved O2 residuals are shown in the following figures O2 residuals by station (-0.01 ยตmol/kg OXYGEN-BTLOXY 0.01 ยตmol/kg). through Deep O2 residuals by station (Pressure >= 2000dbar).. [image]O2 residuals by station (-0.01 ยตmol/kg โ‰ค OXYGEN-BTLOXY โ‰ค 0.01 ยตmol/kg). [image]O2 residuals by pressure (-0.01 ยตmol/kg โ‰ค OXYGEN-BTLOXY โ‰ค 0.01 ยตmol/kg). [image]Deep O2 residuals by station (Pressure >= 2000dbar). The standard deviations of 5.21 (ยตmol/kg) for all dissolved oxygen bottle data values and 3.52 (ยตmol/kg) for deep dissolved oxygen values are only presented as general indicators of the goodness of fit. CLIVAR GO-SHIP standards for CTD dissolved oxygen data are < 1% accuracy against on board Winkler titrated dissolved O2 lab measurements. A number of complications arose with the acquisition and processing of CTD dissolved oxygen data. โ€ข New software used to fit the data is not working as intended, and the data will be re-fit post cruise after a thorough checking of the code. โ€ข SBE43 (S/N: 430255) failed on the test station, spiking and subsequently reporting negative values at 200 db. โ€ข SBE43 (S/N: 431136) was placed on the CTD before station 1 and replaced at station 73 due to growing noise in the signal. โ€ข SBE43 (S/N: 430275) was placed on the CTD before station 74 until station 76 and was noted to have a similarly noisy signal. โ€ข SBE43 (S/N: 430080) was borrowed from ASC and put on the CTD before station 77 until the end of the cruise. โ€ข Technicians rerouted the exhaust lines from the primary sensors for a straighter fit before station 72. All compromised data signals were recorded and coded in the data files. The bottle trip levels affected by the signals were coded and are included in the bottle data comments section of the APPENDIX. [Mill82] Millard, R. C., Jr., โ€œCTD calibration and data processing techniques at WHOI using the practical salinity scale,โ€ Proc. Int. STD Conference and Workshop, p. 19, Mar. Tech. Soc., La Jolla, Ca. (1982). [Owen85] Owens, W. B. and Millard, R. C., Jr., โ€œA new algorithm for CTD oxygen calibration,โ€ Journ. of Am. Meteorological Soc., 15, p. 621 (1985). 4 SALINITY PIs * Susan Becker * James Swift Technicians * John Calderwood * Kelsey Vogel 4.1 Equipment and Techniques Two Guildline Autosals, model 8400B salinometer (S/N 69-180) and model 8400A salinometer (S/N 57-526) located in salinity analysis room, were used for all salinity measurements. Autosal model 8400B was serviced prior to NBP1701 and remained on ship. Autosal model 8400A was serviced prior to P06W and sent with other equipment in June. The salinometer readings were logged on a computer using in house LabView program developed by Carl Mattson. The Autosal water bath temperature was set to 24ยฐC. The laboratoryโ€™s temperature was also set and maintained to 22ยฐC. This is to ensure stabilize reading values and improve accuracy. Salinity analyses were performed after samples had equilibrated to laboratory temperature range of 22-25ยฐC, usually 6 hours after collection. The salinometer was standardized for each group of samples analyzed (usually 2 casts and up to 72 samples) using two bottles of standard seawater: one at the beginning and end of each set of measurements. The salinometer output was logged to a computer file. The software prompted the analyst to flush the instrumentโ€™s cell and change samples when appropriate. Prior to each run a sub-standard flush, approximately 200 ml, of the conductivity cell was conducted to flush out the DI water used in between runs. For each calibration standard, the salinometer cell was initially flushed 2 times before a set of conductivity ratio reading was taken. For each sample, the salinometer cell was initially flushed at least 2 times before a set of conductivity ratio readings were taken. IAPSO Standard Seawater Batch P-160 was used to standardize all casts. [image] 4.2 Sampling and Data Processing The salinity samples were collected in 200 ml Kimax high-alumina borosilicate bottles that had been rinsed at least three times with sample water prior to filling. The bottles were sealed with custom- made plastic insert thimbles and Nalgene screw caps. This assembly provides very low container dissolution and sample evaporation. Prior to sample collection, inserts were inspected for proper fit and loose inserts replaced to insure an airtight seal. Laboratory temperature was also monitored electronically throughout the cruise. PSS-78 salinity [UNESCO1981] was calculated for each sample from the measured conductivity ratios. The offset between the initial standard seawater value and its reference value was applied to each sample. Then the difference (if any) between the initial and final vials of standard seawater was applied to each sample as a linear function of elapsed run time. The corrected salinity data was then incorporated into the cruise database. 4.3 Narrative Autosal 69-180 was left on the ship in good working condition, however upon return for P06W the autosal was not circulating water. The stir motor drive was blown and pumps were not pulling water. The stir motor drive was fixed with a replaced rubber band on the motor. The pumps not pulling water was fixed by cleaning the air filter, straightening kinks in tubing, and reattaching sampling tubing to tubing to sample chamber. Autosal 57-526 was then used from station 1 to 65, when water was noticed in the manifold. Analysis then returned to Autosal 69-180 from stations 66 to 75, when higher than normal readings were reported and lack of drawing water from sample bottle. Autosal 57-526 was then used from stations 76 to 80 until suppression switch stopped working on Autosal 57-526. The problem on Autosal 69-180 was hypothesized to be oxidation accumulating on the connectors, which was fixed by disconnecting and reconnecting connectors multiple times. Autosal 69-180 was then used from stations 81 to 123, when Autosal 57-526 appeared to be working again. Autosal 57-526 was then used from stations 124 to 135, when readings were unstable, possibly related to earlier switch issues, and subsequently not used. Autosal 69-180 was used from stations 136-143, and ended the cruise in good working order. Autosal 57-526 has been deemed to need servicing before further samples can be run on it. Autosal 69-180 Autosal 57-526 UTC Time Date Swapped โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” Stations Run Stations Run - -------------- -------------- --------------------- - 1-65 2017-07-05 -------------- -------------- --------------------- 66-75 - 2017-07-18 -------------- -------------- --------------------- - 76-80 2017-07-21 -------------- -------------- --------------------- 81-123 - 2017-07-25 -------------- -------------- --------------------- - 124-135 2017-08-08 -------------- -------------- --------------------- 136-143 - 2017-08-11 -------------- -------------- --------------------- **Total: 58** **Total: 85** - [UNESCO1981] UNESCO 1981. Background papers and supporting data on the Practical Salinity Scale, 1978. UNESCO Technical Papers in Marine Science, No. 37 144. 5 NUTRIENTS PIs * Susan Becker * James Swift Technicians * Susan Becker * David Cervantes 5.1 Summary of Analysis โ€ข 4816 samples from 144 CTD stations, including the test station โ€ข The cruise started with new pump tubes and they were changed 3 times, before stations 031, 081, and 122. โ€ข 7 sets of Primary/Secondary standards were made up over the course of the cruise. โ€ข The cadmium column efficiency was check periodically and ranged between 93%-100%. The column was replaced in/when the efficiency dropped below 96%. 5.2 Equipment and Techniques Nutrient analyses (phosphate, silicate, nitrate+nitrite, and nitrite) were performed on a Seal Analytical continuous-flow AutoAnalyzer 3 (AA3). The methods used are described by Gordon et al [Gordon1992] Hager et al. [Hager1972], and Atlas et al. [Atlas1971]. Details of modification of analytical methods used in this cruise are also compatible with the methods described in the nutrient section of the GO-SHIP repeat hydrography manual (Hydes et al., 2010) [Hydes2010]. 5.3 Nitrate/Nitrite Analysis A modification of the Armstrong et al. (1967) [Armstrong1967] procedure was used for the analysis of nitrate and nitrite. For nitrate analysis, a seawater sample was passed through a cadmium column where the nitrate was reduced to nitrite. This nitrite was then diazotized with sulfanilamide and coupled with N-(1-naphthyl)-ethylenediamine to form a red dye. The sample was then passed through a 10mm flowcell and absorbance measured at 540nm. The procedure was the same for the nitrite analysis but without the cadmium column. **REAGENTS** Sulfanilamide Dissolve 10g sulfamilamide in 1.2N HCl and bring to 1 liter volume. Add 2 drops of 40% surfynol 465/485 surfactant. Store at room temperature in a dark poly bottle. Note: 40% Surfynol 465/485 is 20% 465 plus 20% 485 in DIW. N-(1-Naphthyl)-ethylenediamine dihydrochloride (N-1-N) Dissolve 1g N-1-N in DIW, bring to 1 liter volume. Add 2 drops 40% surfynol 465/485 surfactant. Store at room temperature in a dark poly bottle. Discard if the solution turns dark reddish brown. Imidazole Buffer Dissolve 13.6g imidazole in ~3.8 liters DIW. Stir for at least 30 minutes to completely dissolve. Add 60 ml of CuSO4 + NH4Cl mix (see below). Add 4 drops 40% Surfynol 465/485 surfactant. Let sit overnight before proceeding. Using a calibrated pH meter, adjust to pH of 7.83-7.85 with 10% (1.2N) HCl (about 10 ml of acid, depending on exact strength). Bring final solution to 4L with DIW. Store at room temperature. NH4Cl + CuSO4 mix Dissolve 2g cupric sulfate in DIW, bring to 100 m1 volume (2%). Dissolve 250g ammonium chloride in DIW, bring to l liter volume. Add 5ml of 2% CuSO4 solution to this NH4Cl stock. This should last many months. 5.4 Phosphate Analysis Ortho-Phosphate was analyzed using a modification of the Bernhardt and Wilhelms (1967) [Bernhardt1967] method. Acidified ammonium molybdate was added to a seawater sample to produce phosphomolybdic acid, which was then reduced to phosphomolybdous acid (a blue compound) following the addition of dihydrazine sulfate. The sample was passed through a 10mm flowcell and absorbance measured at 820nm (880nm after station 59, see section on analytical problems for details). **REAGENTS** Ammonium Molybdate H2SO4 sol'n Pour 420 ml of DIW into a 2 liter Ehrlenmeyer flask or beaker, place this flask or beaker into an ice bath. SLOWLY add 330 ml of conc H2SO4. This solution gets VERY HOT!! Cool in the ice bath. Make up as much as necessary in the above proportions. Dissolve 27g ammonium molybdate in 250ml of DIW. Bring to 1 liter volume with the cooled sulfuric acid sol'n. Add 3 drops of 15% DDS surfactant. Store in a dark poly bottle. Dihydrazine Sulfate Dissolve 6.4g dihydazine sulfate in DIW, bring to 1 liter volume and refrigerate. 5.5 Silicate Analysis Silicate was analyzed using the basic method of Armstrong et al. (1967). Acidified ammonium molybdate was added to a seawater sample to produce silicomolybdic acid which was then reduced to silicomolybdous acid (a blue compound) following the addition of stannous chloride. The sample was passed through a 10mm flowcell and measured at 660nm. **REAGENTS** Tartaric Acid Dissolve 200g tartaric acid in DW and bring to 1 liter volume. Store at room temperature in a poly bottle. Ammonium Molybdate Dissolve 10.8g Ammonium Molybdate Tetrahydrate in 1000ml dilute H2SO4. (Dilute H2SO4 = 2.8ml conc H2SO4 or 6.4ml of H2SO4 diluted for PO4 moly per liter DW) (dissolve powder, then add H2SO4) Add 3-5 drops 15% SDS surfactant per liter of solution. Stannous Chloride stock: (as needed) Dissolve 40g of stannous chloride in 100 ml 5N HCl. Refrigerate in a poly bottle. NOTE: Minimize oxygen introduction by swirling rather than shaking the solution. Discard if a white solution (oxychloride) forms. working: (every 24 hours) Bring 5 ml of stannous chloride stock to 200 ml final volume with 1.2N HCl. Make up daily - refrigerate when not in use in a dark poly bottle. 5.6 Sampling Nutrient samples were drawn into 40 ml polypropylene screw-capped centrifuge tubes. The tubes and caps were cleaned with 10% HCl and rinsed 2-3 times with sample before filling. Samples were analyzed within 1-3 hours after sample collection, allowing sufficient time for all samples to reach room temperature. The centrifuge tubes fit directly onto the sampler. 5.7 Data Collection and Processing Data collection and processing was done with the software (ACCE ver 6.10) provided with the instrument from Seal Analytical. After each run, the charts were reviewed for any problems during the run, any blank was subtracted, and final concentrations (micro moles/liter) were calculated, based on a linear curve fit. Once the run was reviewed and concentrations calculated a text file was created. That text file was reviewed for possible problems and then converted to another text file with only sample identifiers and nutrient concentrations that was merged with other bottle data. 5.8 Standards and Glassware Calibration Primary standards for silicate (Na2SiF6), nitrate (KNO3), nitrite (NaNO2), and phosphate (KH2PO4) were obtained from Johnson Matthey Chemical Co. and/or Fisher Scientific. The supplier reports purities of >98%, 99.999%, 97%, and 99.999 respectively. All glass volumetric flasks and pipettes were gravimetrically calibrated prior to the cruise. The primary standards were dried and weighed out to 0.1mg prior to the cruise. The exact weight was noted for future reference. When primary standards were made, the flask volume at 20C, the weight of the powder, and the temperature of the solution were used to buoyancy-correct the weight, calculate the exact concentration of the solution, and determine how much of the primary was needed for the desired concentrations of secondary standard. Primary and secondary standards were made up every 7-10days. The new standards were compared to the old before use. All the reagent solutions, primary and secondary standards were made with fresh distilled deionized water (DIW). Standardizations were performed at the beginning of each group of analyses with working standards prepared every 10-12 hours from a secondary. Working standards were made up in low nutrient seawater (LNSW). two different batches of LNSW were used on the cruise. LNSW, was collected off shore of coastal California and treated in the lab. The water was first filtered through a 0.45 micron filter then re- circulated for ~8 hours through a 0.2 micron filter, passed a UV lamp and through a second 0.2 micron filter. The actual concentration of nutrients in this water was empirically determined during the standardization calculations. The concentrations in micro-moles per liter of the working standards used were: - N+N PO_4 SIL NO2 NH_4 (uM) (uM) (uM) (uM) (uM) โ€” โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” 0 0.0 0.0 0.0 0.0 0.0 3 15.50 1.2 60 0.50 2.0 5 31.00 2.4 120 1.00 4.0 7 46.50 3.6 180 1.50 6.0 5.9 Quality Control All final data was reported in micro-moles/kg. NO^3, PO_4, and NO2 were reported to two decimals places and SIL to one. Accuracy is based on the quality of the standards the levels are: NO^3 0.05 ยตM (micro moles/Liter) PO_4 0.004 ยตM SIL 2-4 ยตM NO2 0.05 ยตM As is standard ODF practice, a deep calibration "check" sample was run with each set of samples to estimate precision within the cruise. The data are tabulated below. Parameter Concentration (ยตM) stddev โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€” NO^3 34.14 0.18 PO_4 2.40 0.01 SIL 96.7 0.4 Reference materials for nutrients in seawater (RMNS) were also used as a check sample run once a day. The RMNS preparation, verification, and suggested protocol for use of the material are described by [Aoyama2006] [Aoyama2007], [Aoyama2008] and Sato [Sato2010]. RMNS batch BV was used on this cruise, with each bottle being used once or twice before being discarded and a new one opened. Data are tabulated below. Parameter Concentration stddev assigned conc - (ยตmol/kg) - (ยตmol/kg) โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” NO^3 36.1 0.12 36.19 PO_4 2.54 0.02 2.56 Sil 105.1 0.4 104.6 NO2 0.06 0.00 0.05 5.10 Analytical Problems No major analytical problems. [image] [Armstrong1967] Armstrong, F.A.J., Stearns, C.A., and Strickland, J.D.H., "The measurement of upwelling and subsequent biological processes by means of the Technicon Autoanalyzer and associated equipment," Deep-Sea Research, 14, pp.381-389 (1967). [Atlas1971] Atlas, E.L., Hager, S.W., Gordon, L.I., and Park, P.K., "A Practical Manual for Use of the Technicon AutoAnalyzer in Seawater Nutrient Analyses Revised," Technical Report 215, Reference 71-22, p.49, Oregon State University, Department of Oceanography (1971). [Aoyama2006] Aoyama, M., 2006: 2003 Intercomparison Exercise for Reference Material for Nutrients in Seawater in a Seawater Matrix, Technical Reports of the Meteorological Research Institute No.50, 91pp, Tsukuba, Japan. [Aoyama2007] Aoyama, M., Susan B., Minhan, D., Hideshi, D., Louis, I. G., Kasai, H., Roger, K., Nurit, K., Doug, M., Murata, A., Nagai, N., Ogawa, H., Ota, H., Saito, H., Saito, K., Shimizu, T., Takano, H., Tsuda, A., Yokouchi, K., and Agnes, Y. 2007. Recent Comparability of Oceanographic Nutrients Data: Results of a 2003 Intercomparison Exercise Using Reference Materials. Analytical Sciences, 23: 1151-1154. [Aoyama2008] Aoyama M., J. Barwell-Clarke, S. Becker, M. Blum, Braga E. S., S. C. Coverly,E. Czobik, I. Dahllof, M. H. Dai, G. O. Donnell, C. Engelke, G. C. Gong, Gi-Hoon Hong, D. J. Hydes, M. M. Jin, H. Kasai, R. Kerouel, Y. Kiyomono, M. Knockaert, N. Kress, K. A. Krogslund, M. Kumagai, S. Leterme, Yarong Li, S. Masuda, T. Miyao, T. Moutin, A. Murata, N. Nagai, G.Nausch, M. K. Ngirchechol, A. Nybakk, H. Ogawa, J. van Ooijen, H. Ota, J. M. Pan, C. Payne, O. Pierre-Duplessix, M. Pujo-Pay, T. Raabe, K. Saito, K. Sato, C. Schmidt, M. Schuett, T. M. Shammon, J. Sun, T. Tanhua, L. White, E.M.S. Woodward, P. Worsfold, P. Yeats, T. Yoshimura, A.Youenou, J. Z. Zhang, 2008: 2006 Intercomparison Exercise for Reference Material for Nutrients in Seawater in a Seawater Matrix, Technical Reports of the Meteorological Research Institute No. 58, 104pp. [Bernhardt1967] Bernhardt, H., and Wilhelms, A., "The continuous determination of low level iron, soluble phosphate and total phosphate with the AutoAnalyzer," Technicon Symposia, I,pp.385-389 (1967). [Gordon1992] Gordon, L.I., Jennings, J.C., Ross, A.A., Krest, J.M., "A suggested Protocol for Continuous Flow Automated Analysis of Seawater Nutrients in the WOCE Hydrographic Program and the Joint Global Ocean Fluxes Study," Grp. Tech Rpt 92-1, OSU College of Oceanography Descr. Chem Oc. (1992). [Hager1972] Hager, S.W., Atlas, E.L., Gordon L.I., Mantyla, A.W., and Park, P.K., " A comparison at sea of manual and autoanalyzer analyses of phosphate, nitrate, and silicate ," Limnology and Oceanography, 17,pp.931-937 (1972). [Hydes2010] Hydes, D.J., Aoyama, M., Aminot, A., Bakker, K., Becker, S., Coverly, S., Daniel,A.,Dickson,A.G., Grosso, O., Kerouel, R., Ooijen, J. van, Sato, K., Tanhua, T., Woodward, E.M.S., Zhang, J.Z., 2010. Determination of Dissolved Nutrients (N, P, Si) in Seawater with High Precision and Inter-Comparability Using Gas-Segmented Continuous Flow Analysers, In: GO-SHIP Repeat Hydrography Manual: A Collection of Expert Reports and Guidelines. IOCCP Report No. 14, ICPO Publication Series No 134. [Kerouel1997] Kerouel, R., Aminot, A., โ€œFluorometric determination of ammonia in sea and estuarine waters by direct segmented flow analysis.โ€ Marine Chemistry, vol 57, no. 3-4, pp. 265-275, July 1997. [Sato2010] Sato, K., Aoyama, M., Becker, S., 2010. RMNS as Calibration Standard Solution to Keep Comparability for Several Cruises in the World Ocean in 2000s. In: Aoyama, M., Dickson, A.G., Hydes, D.J., Murata, A., Oh, J.R., Roose, P., Woodward, E.M.S., (Eds.), Comparability of nutrients in the worldโ€™s ocean. Tsukuba, JAPAN: MOTHER TANK, pp 43-56. 6 OXYGEN ANALYSIS PIs * Susan Becker * James Swift Technicians * Andrew Barna * Courtney Schatzman 6.1 Equipment and Techniques Dissolved oxygen analyses were performed with an SIO/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 PC LabView software. Thiosulfate was dispensed by a Dosimat 765 buret driver fitted with a 1.0 ml burette. ODF used a whole-bottle modified- Winkler titration following the technique of Carpenter [Carpenter1965] with modifications by [Culberson1991] but with higher concentrations of potassium iodate standard approximately 0.012N, and thiosulfate solution approximately 55 gm/l. Pre-made liquid potassium iodate standards were run every day (approximately every 4-5 stations), unless changes were made to the system or reagents. Reagent/distilled water blanks were determined every day or more often if a change in reagents required it to account for presence of oxidizing or reducing agents. 6.2 Sampling and Data Processing 4790 oxygen measurements were made. Samples were collected for dissolved oxygen analyses soon after the rosette was brought on board. Using a silicone drawing tube, nominal 125ml volume-calibrated iodine flasks were rinsed 3 times with minimal agitation, then filled and allowed to overflow for at least 3 flask volumes. The sample drawing temperatures were measured with an electronic resistance temperature detector (RTD) embedded in the drawing tube. These temperatures were used to calculate umol/kg concentrations, and as a diagnostic check of bottle integrity. Reagents (MnCl_2 then NaI/NaOH) were added to fix the oxygen before stoppering. The flasks were shaken twice (10-12 inversions) to assure thorough dispersion of the precipitate, once immediately after drawing, and then again after about 30-40 minutes. The samples were analyzed within 2-14 hours of collection, and the data incorporated into the cruise database. Thiosulfate normalities were calculated for each standardization and corrected to 20ยฐC. The 20ยฐC normalities and the blanks were plotted versus time and were reviewed for possible problems. The blanks and thiosulfate normalities for each batch of thiosulfate were stable enough that no smoothing was necessary. 6.3 Volumetric Calibration Oxygen flask volumes were determined gravimetrically with degassed deionized water to determine flask volumes at ODF's chemistry laboratory. This is done once before using flasks for the first time and periodically thereafter when a suspect volume is 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. 6.4 Standards Liquid potassium iodate standards were prepared in 6 liter batches and bottled in sterile glass bottles at ODF's chemistry laboratory prior to the expedition. The normality of the liquid standard was determined by calculation from weight. The standard was supplied by Alfa Aesar and has a reported purity of 99.4-100.4%. All other reagents were "reagent grade" and were tested for levels of oxidizing and reducing impurities prior to use. 6.5 Narrative Setup occurred in Sydney, Australia starting June 29th, 2017. The equipment was already on board the RV Palmer from NBP1701 in January. During setup it was discovered that the 4 large reagent jugs (~4L each) were not present. This had the effect of limiting the amount of reagents which could be made in advance. The primary consequence of this is that each batch of Thiosulfate would be independent. Setup otherwise went smoothly and the analysis rig was running, secured, and standardizing before leaving port on July 3rd. Scientific stations occurred within 24 hours of leaving port. Issues were minor, occasional communication issues occurred between the analytical computer and the 1ml burette, resulting in the restart of the computer. The communication problems did not result in any lost sample analysis. On station 14, deep samples (bottles 2-7) showed significant discrepancies from the CTD O2 profile and from adjacent bottles, the cause was not identified. Around station 112 a KIO3 standard (2017B.2) change resulted in an out of spec jump in the Thiosulfate normality. The existing thiosulfate was subsequently standardized with both and OSIL Oxygen standard (0.1N) and a second ODF oxygen standard. It was determined that the 2017B.2 standard which had been swapped in was the source of the jump. This batch was reported to the shore calibration facility which observed a similar thiosulfate normality discrepancy when some of standard 2017B.2 was rerun. An OSIL oxygen standard was run against the usual ODF oxygen standard in the process of troubleshooting. The OSIL standardization resulted in a thiosulfate normality within specifications of the last accepted good standardization using the ODF oxygen standard. The OSIL standardization followed the same procedures as normal with the exception of using an Eppendorf pipette to dispense the standard. A standardization run after station 134 resulted in constantly increasing thiosulfate titration values, with detectable increases even in the minutes between each titration. The likely cause of which was a decreasing concentration of thiosulfate from an infection. The existing thiosulfate was subsequently discarded and all glassware, burettes, and tubing was acid washed. A new batch of thiosulfate was made and used for the remaining stations for the cruise. While the normal rest period for a new batch of thiosulfate could not be done, the normality as reported by each standardization run (approx. every 24 hours) showed excellent stability. The necessity of smoothing the normality of each batch of thiosulfate was considered separately for each batch. There was no drift or trend observed in any of the batches, so no smoothing procedure was performed. A total of 5 batches were made and used throughout the cruise. [image]Preliminary dissolved oxygen section of P06W [Carpenter1965] Carpenter, J. H., โ€œThe Chesapeake Bay Institute technique for the Winkler dissolved oxygen method,โ€ Limnology and Oceanography, 10, pp. 141-143 (1965). [Culberson1991] Culberson, C. H., Knapp, G., Stalcup, M., Williams, R. T., and Zemlyak, F., โ€œA comparison of methods for the deter mination of dissolved oxygen in seawater,โ€ Repor t WHPO 91-2, WOCE Hydrographic Programme Office (Aug 1991). 7 TOTAL ALKALINITY PI * Andrew G. Dickson - Scripps Institution of Oceanography Technicians * Manuel Belmonte * Derek Smith 7.1 Total Alkalinity The total alkalinity of a sea water sample is defined as the number of moles of hydrogen ion equivalent to the excess of proton acceptors (bases formed from weak acids with a dissociation constant K โ‰ค 10-4.5 at 25ยฐC and zero ionic strength) over proton donors (acids with K > 10-4.5) in 1 kilogram of sample. 7.2 Total Alkalinity Measurement System Samples are dispensed using a Sample Delivery System (SDS) consisting of a volumetric pipette, various relay valves, and two air pumps controlled by LabVIEW 2012. Before filling the jacketed cell with a new sample for analysis, the volumetric pipette is cleared of any residual from the previous sample with the aforementioned air pumps. The pipette is then rinsed with new sample and filled, allowing for overflow and time for the sample temperature to equilibrate. The sample bottle temperature is measured using a DirecTemp thermistor probe inserted into the sample bottle and the volumetric pipette temperature is measured using a DirecTemp surface probe placed directly on the pipette. These temperature measurements are used to convert the sample volume to mass for analysis. Samples are analyzed using an open cell titration procedure using two 250 mL jacketed cells. One sample is undergoing titration while the second is being prepared and equilibrating to 20ยฐC for analysis. After an initial aliquot of approximately 2.3-2.4 mL of standardized hydrochloric acid (~0.1M HCl in ~0.6M NaCl solution), the sample is stirred for 5 minutes while air is bubbled into it at a rate of 200 scc/m to remove any liberated carbon dioxide gas. A Metrohm 876 Dosimat Plus is used for all standardized hydrochloric acid additions. After equilibration, ~19 aliquots of 0.04 ml are added. Between the pH range of 3.5 to 3.0, the progress of the titration is monitored using a pH glass electrode/reference electrode cell, and the total alkalinity is computed from the titrant volume and e.m.f. measurements using a non-linear least-squares approach ([Dickson2007]). An Agilent 34970A Data Acquisition/Switch Unit with a 34901A multiplexer is used to read the voltage measurements from the electrode and monitor the temperatures from the sample, acid, and room. The calculations for this procedure are performed automatically using LabVIEW 2012. 7.3 Sample Collection Samples for total alkalinity measurements were taken at all P06W Stations (1-143) except for stations 16, 20, 56, 60, 69 and 72. Two Niskin bottles at each station were sampled twice for duplicate measurements except for stations where 24 or less Niskin bottles were sampled. Using silicone tubing, the total alkalinity samples were drawn from Niskin bottles into 250 mL Pyrex bottles, making sure to rinse the bottles and Teflon sleeved glass stoppers at least twice before the final filling. A headspace of approximately 3 mL was removed and 0.12 mL of saturated mercuric chloride solution was added to each sample for preservation. After sampling was completed, each sampleโ€™s temperature was equilibrated to approximately 20ยฐC using a Thermo Scientific RTE water bath. 7.4 Problems and Troubleshooting The RVIB Nathaniel B. Palmer is a fantastic research vessel. However, our electrodes appeared to continually pick up larger than expected interference from the labโ€™s neighboring instruments or the ship itself. Electrode plots could show increased electrode sensitivity over time. Luckily, enough electrodes were brought on P06W and replacing them minimized bad measurements. Any unusual measurements (poor electrode plot / profile outlier) were reran when possible. Normally after samples are collected, they are placed into a water bath to equilibrate the sample temperature near 20ยฐC, the temperature at which the sample is measured. This is normally fine when the lab temperature is within 2ยฐC of 20ยฐC. The lab temperature for P06W ranged from 19ยฐC to 25ยฐC due to some air conditioning issues. At the beginning of the cruise, before the air conditioning was fixed, lab temperatures ranged from 20ยฐC to 25ยฐC. Once the air conditioning was fixed, the temperature ranged from 19ยฐC to 22ยฐC. This constantly delayed the titration start times. To remedy the situation, we equilibrated the sample temperatures to about 22.5ยฐC at the start of the cruise and 20ยฐC after the lab temperatures were more stable. This strategy enabled most of the sample temperatures to not exceed a 0.2ยฐC range while being titrated. Throughout the cruise, varying issues resulted from the Sample Delivery System. At the start of the cruise (during station 5), Sample Delivery System B would not fill the pipette completely so it was replaced with Sample Delivery System A. About a third of the way into the cruise (before station 55), a shift in Sample Delivery System Aโ€™s delivery volume was noticed causing smaller samples sizes to be dispensed: A calibration using a manual pipette resolved this issue. Once again, towards the end of the cruise (during station 140) Sample Delivery Station Aโ€™s dispensed volume shifted and another calibration was performed. Lastly, throughout the cruise, the Sample Delivery Systemโ€™s program would freeze in Deliver Sample mode or Prepare Pipette mode and caused a few sample bottles to be emptied. This resulted in lost samples due to the novice operators. Despite these issues, a minimal amount of samples were lost, and the amount of samples that were suspected of being low in volume were reran or flagged if a rerun was not possible. 7.5 Quality Control Dickson laboratory Certified Reference Material (CRM) Batch 165 was used to determine the accuracy of the total alkalinity analyses. The total alkalinity certified value for this batch is: โ€ข Batch 165 2214.09 ยฑ 0.41 ยตmol/kg (32;16) The cited uncertainties represent the standard deviation. Figures in parentheses are the number of analyses made (total number of analyses; number of separate bottles analyzed). At least one reference material was analyzed at every I09N stations resulting in 110 reference material analyses. On I09N, the measured total alkalinity value for each batch is: โ€ข Batch 165 2213.37 ยฑ 3.94 ยตmol kg-1 (179) [mean ยฑ std. dev. (n)] If greater than 24 Niskin bottles were sampled at a station, two Niskin bottles on that station were sampled twice to conduct duplicate analyses. If 24 or less Niskin bottles were sampled at a station, only one Niskin on that station was sampled twice for duplicate analyses. The standard deviation for the duplicates measured on P06W is: Duplicate Standard Deviation ยฑ 3.52 ยตmol kg-1 (196) [ยฑ std. dev. (n)] The total alkalinity measurements for each P06W stations have not been compared to measurements taken from the neighboring P06W 2017 stations and the P06W 2009 stations of similar if not identical coordinates. 3136 total alkalinity values were submitted for P06W. The total alkalinity of the entire transect is shown as a section in P06W Alkalinty Section. Although most corrections have been applied and it is unlikely that any additional corrections will need to be performed, this data should be considered preliminary until a more thorough analysis of the data can take place on shore, especially during the stations where the SDS Pipette Boards were having problems. [image]P06W Alkalinty Section Section of total alkalinity along P06W (Stations 1 to 143). 8 DISSOLVED INORGANIC CARBON (DIC) PIโ€™s * Rik Wanninkhof (NOAA/AOML) * Richard A. Feely (NOAA/PMEL) Technicians * Andrew Collins (NOAA/PMEL) * Charles Featherstone (NOAA/AOML) 8.1 Sample collection Samples for DIC measurements were drawn (according to procedures outlined in the PICES Publication, *Guide to Best Practices for Ocean CO2 Measurements* [Dickson2007]) from Niskin bottles into 294 ml borosilicate glass bottles using silicone tubing. The flasks were rinsed once and filled from the bottom with care not to entrain any bubbles, overflowing by at least one-half volume. The sample tube was pinched off and withdrawn, creating a 6 ml headspace, followed by 0.16 ml of saturated HgCl_2 solution which was added as a preservative. The sample bottles were then sealed with glass stoppers lightly covered with Apiezon-L grease and were stored at room temperature for a maximum of 12 hours. 8.2 Equipment The analysis was done by coulometry with two analytical systems (AOML 3 and AOML 4) used simultaneously on the cruise. Each system consisted of a coulometer (CM5015 UIC Inc) coupled with a Dissolved Inorganic Carbon Extractor (DICE). The DICE system was developed by Esa Peltola and Denis Pierrot of NOAA/AOML and Dana Greeley of NOAA/PMEL to modernize a carbon extractor called SOMMA ([Johnson1985], [Johnson1987], [Johnson1993], [Johnson1992], [Johnson1999]). The two DICE systems (PMEL 1 and PMEL 2) were set up in a seagoing container modified for use as a shipboard laboratory on the aft main working deck of the RVIB Nathaniel B. Palmer. 8.3 DIC Analysis In coulometric analysis of DIC, all carbonate species are converted to CO2 (gas) by addition of excess hydrogen ion (acid) to the seawater sample, and the evolved CO2 gas is swept into the titration cell of the coulometer with pure air or compressed nitrogen, where it reacts quantitatively with a proprietary reagent based on ethanolamine to generate hydrogen ions. In this process, the solution changes from blue to colorless, triggering a current through the cell and causing coulometrical generation of OH^- ions at the anode. The OH^- ions react with the H^+ and the solution turns blue again. A beam of light is shone through the solution, and a photometric detector at the opposite side of the cell senses the change in transmission. Once the percent transmission reaches its original value, the coulometric titration is stopped, and the amount of CO2 that enters the cell is determined by integrating the total change during the titration. 8.4 DIC Calculation Calculation of the amount of CO2 injected was according to the CO2 handbook [DOE1994]. The concentration of CO2 ([CO2]) in the samples was determined according to: (Counts - Blank * Run Time) * K ยตmol/count [CO2] = Cal. Factor * โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” pipette volume * density of sample where Cal. Factor is the calibration factor, Counts is the instrument reading at the end of the analysis, Blank is the counts/minute determined from blank runs performed at least once for each cell solution, Run Time is the length of coulometric titration (in minutes), and K is the conversion factor from counts to micromoles. The instrument has a salinity sensor, but all DIC values were recalculated to a molar weight (ยตmol/kg) using density obtained from the CTDโ€™s salinity. The DIC values were corrected for dilution due to the addition of 0.12 ml of saturated HgCl_2 used for sample preservation. The total water volume of the sample bottles was 305.55 ml (calibrated by Dana Greeley, AOML). The correction factor used for dilution was 1.0004. A correction was also applied for the offset from the CRM. This additive correction was applied for each cell using the CRM value obtained at the beginning of the cell. The average (ยฑ SD) correction was 0.97 ยฑ 1.22 ยตmol/kg for PMEL 1 and 1.00 ยฑ 1.00 ยตmol/kg for PMEL 2. The coulometer cell solution was replaced after 25 - 28 mg of carbon was titrated, typically after 9 - 12 hours of continuous use. The average (ยฑ SD) blanks for PMEL 1 and PMEL 2 were 17.8 ยฑ 5.8 and 18.3 ยฑ 5.8 counts, respectively. 8.5 Calibration, Accuracy, and Precision The stability of each coulometer cell solution was confirmed three different ways. 1. Gas loops were run at the beginning of each cell 2. CRMโ€™s supplied by Dr. A. Dickson of SIO, were measured near the beginning; middle and end of each cell 3. Duplicate samples from the same niskin were run throughout the life of the cell solution. Each coulometer was calibrated by injecting aliquots of pure CO2 (99.999%) by means of an 8-port valve [Wilke1993] outfitted with two calibrated sample loops of different sizes (~1ml and ~2ml). The instruments were each separately calibrated at the beginning of each cell with a minimum of two sets of these gas loop injections. The accuracy of the DICE measurement is determined with the use of standards (Certified Reference Materials (CRMs), consisting of filtered and UV irradiated seawater) supplied by Dr. A. Dickson of Scripps Institution of Oceanography (SIO). The CRM accuracy is determined manometrically on land in San Diego and the DIC data reported to the data base have been corrected to this batch 165 CRM value. The CRM certified value for this batch is 2064.33 ยตmol/kg. The precision of the two DICE systems can be demonstrated via the replicate samples. Approximately 11.5% of the niskins sampled were duplicates taken as a check of our precision. These replicate samples were interspersed throughout the station analysis for quality assurance and integrity of the coulometer cell solutions. The average absolute difference from the mean of these replicates is 0.6 ยตmol/kg - No major systematic differences between the replicates were observed. The pipette volume was determined by taking aliquots of distilled water from volumes at known temperatures. The weights with the appropriate densities were used to determine the volume of the pipettes. Calibration data during this cruise: UNIT L Loop S Loop Pipette Ave CRM1 Std Dev Dupes โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€” PMEL 1 1.002533 1.006530 27.5812 ml 2064.13, N= 82 1.22 1.56 PMEL 2 1.004927 1.002611 26.3417 ml 2065.25, N= 68 1.24 1.45 8.6 Underway DIC Samples Underway samples were collected from the flow thru system in the Hydro Lab during transit. Discrete DIC samples were collected approximately every 4 hours with duplicates every fifth sample. A total of 80 discrete DIC samples including duplicates were collected while underway. The average difference for replicates of underway DIC samples was 1.24 ยตmol/kg and the average standard deviation was 0.88. 8.7 Summary The overall performance of the analytical equipment was good during the cruise. Several small leaks were fixed in the HSG during the cruise. Including the duplicates, 3,889 samples were analyzed from 143 CTD casts for dissolved inorganic carbon (DIC) which means that there is a DIC value for approximately 81% of the niskins tripped. The distribution of DIC with depth along the 2017 cruise track can be seen in Figure 1, while differences in DIC distributions observed between 2009 and 2017 can be seen in Figure 2. The DIC data reported to the database directly from the ship are to be considered preliminary until a more thorough quality assurance can be completed shore side. [image]Distribution of dissolved inorganic carbon measured during the 2017 GO-SHIP P06 research expedition. [image]Changes observed in the distributions of dissolved inorganic carbon measured during the 2017 P06 occupation compared to those measured during the 2009 P06 occupation. [DOE1994] DOE (U.S. Department of Energy). (1994). *Handbook of Methods for the Analysis of the Various Parameters of the Carbon Dioxide System in Seawater*. Version 2.0. ORNL/CDIAC-74. Ed. A. G. Dickson and C. Goyet. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tenn. [Dickson2007] Dickson, A.G., Sabine, C.L. and Christian, J.R. (Eds.), (2007): *Guide to Best Practices for Ocean CO2 Measurements*. PICES Special Publication 3, 191 pp. [Feely1998] Feely, R.A., R. Wanninkhof, H.B. Milburn, C.E. Cosca, M. Stapp, and P.P. Murphy (1998): *"A new automated underway system for making high precision pCO2 measurements aboard research ships."* Anal. Chim. Acta, 377, 185-191. [Johnson1985] Johnson, K.M., A.E. King, and J. McN. Sieburth (1985): *"Coulometric DIC analyses for marine studies: An introduction."* Mar. Chem., 16, 61-82. [Johnson1987] Johnson, K.M., P.J. Williams, L. Brandstrom, and J. McN. Sieburth (1987): *"Coulometric total carbon analysis for marine studies: Automation and calibration."* Mar. Chem., 21, 117-133. [Johnson1992] Johnson, K.M. (1992): Operator's manual: *"Single operator multiparameter metabolic analyzer (SOMMA) for total carbon dioxide (CT) with coulometric detection."* Brookhaven National Laboratory, Brookhaven, N.Y., 70 pp. [Johnson1993] Johnson, K.M., K.D. Wills, D.B. Butler, W.K. Johnson, and C.S. Wong (1993): *"Coulometric total carbon dioxide analysis for marine studies: Maximizing the performance of an automated continuous gas extraction system and coulometric detector."* Mar. Chem., 44, 167-189. [Johnson1999] Johnson, K.M., Kโˆšโˆ‚rtzinger, A.; Mintrop, L.; Duinker, J.C.; and Wallace, D.W.R. (1999). *Coulometric total carbon dioxide analysis for marine studies: Measurement and interna consistency of underway surface TCO2 concentrations.* Marine Chemistry 67:123-44. [Lewis1998] Lewis, E. and D. W. R. Wallace (1998) Program developed for CO2 system calculations. Oak Ridge, Oak Ridge National Laboratory. http://cdiac.ornl.gov/oceans/co2rprt.html [Wilke1993] Wilke, R.J., D.W.R. Wallace, and K.M. Johnson (1993): "Water-based gravimetric method for the determination of gas loop volume." Anal. Chem. 65, 2403-2406 9 DISCRETE pH ANALYSES (Total Scale) PI * Dr. Andrew Dickson Technicians * Stephanie Mumma * Manuel Belmonte 9.1 Sampling Samples were collected in 250 mL Pyrex glass bottles and sealed using grey butyl rubber stoppers held in place by aluminum-crimped caps. Each bottle was rinsed two times and allowed to overflow by one additional bottle volume. Prior to sealing, each sample was given a 1% headspace and poisoned with 0.02% of the sample volume of saturated mercuric chloride (HgCl_2). Samples were collected only from Niskin bottles that were also being sampled for both total alkalinity and dissolved inorganic carbon in order to completely characterize the carbon system. Additionally, duplicate samples were collected from all stations for quality control purposes. 9.2 Analysis pH was measured spectrophotometrically on the total hydrogen scale using an Agilent 8453 spectrophotometer and in accordance with the methods outlined by Carter et al., 2013. [Carter2013]. A Kloehn V6 syringe pump was used to autonomously fill, mix, and dispense sample through the custom 10cm flow-through jacketed cell. A Thermo NESLAB RTE-7 recirculating water bath was used to maintain the cell temperature at 25.0ยฐC during analyses, and a YSI 4600 precision thermometer and probe were used to monitor and record the temperature of each sample immediately after the spectrophotometric measurements were taken. The indicator meta-cresol purple (mCP) was used to measure the absorbance of light measured at two different wavelengths (434 nm, 578 nm) corresponding to the maximum absorbance peaks for the acidic and basic forms of the indicator dye. A baseline absorbance was also measured and subtracted from these wavelengths. The baseline absorbance was determined by averaging the absorbances from 725-735nm. The ratio of the absorbances was then used to calculate pH on the total scale using the equations outlined in Liu et al., 2011 [Liu2011]. The salinity data used was obtained from the conductivity sensor on the CTD. 9.3 Reagents The mCP indicator dye was made up to a concentration of approximately 2.0mM and a total ionic strength of 0.7 M. A total of four batches were used during P06, Leg 1. The pHs of these batches were adjusted with 0.1 mol kg^-1 solutions of HCl and NaOH (in 0.6 mol kg^-1 NaCl background) to approximately 7.75, measured with a pH meter calibrated with NBS buffers. The indicator was obtained from Dr. Robert Byrne at the University of Southern Florida and was purified using the flash chromatography technique described by Patsavas et al., 2013. [Patsavas2013]. 9.4 Data Processing An indicator dye is itself an acid-base system that can change the pH of the seawater to which it is added. Therefore it is important to estimate and correct for this perturbation to the seawaterโ€™s pH for each batch of dye used during the cruise. To determine this correction, multiple bottles from each station were measured twice, once with a single addition of indicator dye and once with a double addition of indicator dye. The measured absorbance ratio (R) and an isosbestic absorbance (A_{\text{iso}}) were determined for each measurement, where: A_{578} - A_{base} R = โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” A_{434} - A_{base} and A_{iso} = A_{488} - A_{base} The change in R for a given change in A_{iso}, โˆ†{iso}, was then plotted against the measured R-value for the normal amount of dye and fitted with a linear regression. From this fit the slope and y-intercept (b and a respectively) are determined by: โˆ†R/โˆ†A_{iso} = bR + a From this the corrected ratio (R') corresponding to the measured absorbance ratio if no indicator dye were present can be determined by: R' = R - A_{iso} (bR + a) 9.5 Problems and Troubleshooting Many of the samples had a high dissolved gas content and degassed when brought to room temperature. This could be clearly seen in the formation of bubbles inside the sealed sample bottles and in the spectrophotometric pH system (Kloehn syringe pump, sample tubing, and the 10 cm cell). Bubbles were especially difficult to eliminate in the Kloehn syringe pump, which would accumulate large bubbles at the top after running a number of samples from each station. Efforts were made to reduce bubble formation by verifying all pump fittings were tight, slowing down the speed of the syringe pump, and holding samples below 25ยฐC. When bubbles formed during station analysis, they were cleared by the aforementioned methods between samples. Bubbles were also cleared from the syringe by flushing with ethanol, followed by DI water. This method of flushing with ethanol and DI water proved to be effective and removed bubbles when accumulated. These bubbles appeared to have no effect on the samplesโ€™ pH values. On two occasions near the beginning of the P06, Leg 1, the valve on the Kloehn syringe pump appeared to be "sticking" in between ports, resulting in cross-port contamination of the measured sample. The spare Kloehn pump was installed and this issue was not encountered again. The two affected Niskin samples were measured again from the original sample bottles with good results. The Labview software that controls the automated pH system crashed once during P06, Leg 1, resulting in the loss of data for one measurement. The uncorrected pH values were documented in the pH lab notebook. This sample was run again and the resulting pH value for the second analysis was used for data submission. 9.6 Standardization/Results The precision of the data was assessed from measurements of duplicate analyses, replicate analyses (two successive measurements on one bottle), and certified reference material (CRM) Batch 165 (provided by Dr. Andrew Dickson, UCSD). Two duplicate and two replicate measurements were performed on every station when at least twenty- three Niskins were sampled. If less than twenty-three Niskins were sampled, only one duplicate and one replicate measurement were performed. CRMs were measured at the beginning and ending of each day. The precision statistics for P06, Leg 1 are: Duplicate precision ยฑ 0.00057 (n=206) Replicate precision ยฑ 0.00039 (n=244) B165 7.7598 ยฑ 0.00104 (n=78) B165 within-bottle SD ยฑ 0.00026 (n=78) 3478 pH values were submitted for P06, Leg 1. Additional corrections will need to be performed and these data should be considered preliminary until a more thorough analysis of the data can take place on shore. The preliminary pH of the entire transect is shown as a section in pH Section. [image]pH Section Section of preliminary pH measurements on the total scale along P06 cruise track (Stations 1 to 143). [Carter2013] Carter, B.R., Radich, J.A., Doyle, H.L., and Dickson, A.G., "An Automated Spectrometric System for Discrete and Underway Seawater pH Measurements," Limnology and Oceanography: Methods, 2013. [Liu2011] Liu, X., Patsavas, M.C., Byrne R.H., "Purification and Characterization of meta Cresol Purple for Spectrophotometric Seawater pH Measurements," Environmental Science and Technology, 2011. [Patsavas2013] Patsavas, M.C., Byrne, R.H., and Liu X. "Purification of meta-cresol purple and cresol red by flash chromatography: Procedures for ensuring accurate spectrophotometric seawater pH measurements," Marine Chemistry, 2013. 10 CFC-11, CFC-12, CFC-113, AND SF6 Analysts * Jim Happell * David Cooper * Kelly McCabe 10.1 Sample Collection All samples were collected from depth using 10.4 liter Niskin bottles. None of the Niskin bottles used showed a CFC contamination throughout the cruise. All bottles in use remained inside the CTD hanger between casts. Sampling was conducted first at each station, according to WOCE protocol. This avoids contamination by air introduced at the top of the Niskin bottle as water was being removed. A water sample was collected from the Niskin bottle petcock using viton tubing to fill a 300 ml BOD bottle. The viton tubing was flushed of air bubbles. The BOD bottle was placed into a plastic overflow container. Water was allowed to fill BOD bottle from the bottom into the overflow container. The stopper was held in the overflow container to be rinsed. Once water started to flow out of the overflow container the overflow container/BOD bottle was moved down so the viton tubing came out and the bottle was stoppered under water while still in the overflow container. A plastic cap was snapped on to hold the stopper in place. One duplicate sample was taken on every other station from random Niskin bottles. Air samples, pumped into the system using an Air Cadet pump from a Dekoron air intake hose mounted high on the foremast were run when time permitted. Air measurements are used as a check on accuracy. 10.2 Equipment and Technique CFC-11, CFC-12, and SF6 were measured on 129 0f 143 stations for a total of 3500 samples. Salt water flooded the analytical system just after analyzing station 48, which was the cause of most of the missed stations, although some of the added stations with very short station spacing were also skipped. Analyses were performed on a gas chromatograph (GC) equipped with an electron capture detector (ECD). Samples were introduced into the GC-EDC via a purge and dual trap system. 202 ml water samples were purged with nitrogen and the compounds of interest were trapped on a main Porapack N/Carboxen 1000 trap held at ~ -20ยฐC with a Vortec Tube cooler. After the sample had been purged and trapped for 6 minutes at 250ml/min flow, the gas stream was stripped of any water vapor via a magnesium perchlorate trap prior to transfer to the main trap. The main trap was isolated and heated by direct resistance to 180ยฐC. The desorbed contents of the main trap were back-flushed and transferred, with helium gas, over a short period of time, to a small volume focus trap in order to improve chromatographic peak shape. The focus trap was Porapak N and is held at ~ -20ยฐC with a Vortec Tube cooler. The focus trap was flash heated by direct resistance to 180ยฐC to release the compounds of interest onto the analytical pre-columns. The first precolumn was a 5 cm length of 1/16โ€ tubing packed with 80/100 mesh molecular sieve 5A. This column was used to hold back N_2O and keep it from entering the main column. The second pre-column was the first 5 meters of a 60 m Gaspro capillary column with the main column consisting of the remaining 55 meters. The analytical pre-columns were held in-line with the main analytical column for the first 50 seconds of the chromatographic run. After 35 seconds, all of the compounds of interest were on the main column and the pre-column was switched out of line and back-flushed with a relatively high flow of nitrogen gas. This prevented later eluting compounds from building up on the analytical column, eventually eluting and causing the detector baseline signal to increase. The samples were stored at room temperature and analyzed within 24 hours of collection. Every 12 to 18 measurements were followed by a purge blank and a standard. The surface sample was held after measurement and was sent through the process in order to "restrip" it to determine the efficiency of the purging process. 10.3 Calibration A gas phase standard, 33780, was used for calibration. The concentrations of the compounds in this standard are reported on the SIO 2005 absolute calibration scale. 5 calibration curves were run over the course of the cruise. Estimated accuracy is ยฑ 2%. Precision for CFC-12, CFC-11, and SF6 was 1.2%, 1.6% and 2.5% respectively. Estimated limit of detection is 1 fmol/kg for CFC-11, 3 fmol/kg for CFC-12, and 0.1 fmol/kg for SF6 11 DISSOLVED ORGANIC PHOSPHORUS PIs * Angela Knapp (FSU) Technician * Kelly McCabe Marine dissolved organic matter (DOM) is considered a primary substrate for heterotrophic microbes, but can also be used by some nutrient-limited phytoplankton that especially consume dissolved organic phosphorus (DOP) when phosphate (PO4) is scarce. However, very few measurements of surface ocean DOP concentration have been made, which limits our understanding the extent to which DOP is utilized by phytoplankton. The goal of this data collection is to increase the spatial coverage of DOP measurements to constrain the use of DOP as a nutrient source supporting export production and di- nitrogen fixation in the global marine environment. DOP samples were collected from the upper 400 meters at stations with two-degree longitude spacing. A total of 375 samples from 29 stations were collected. All samples were hand filtered through Whatman 25mm Puradisc 0.2 ยตm PES filters. The syringe and filter were rinsed with 40mL of seawater before each 60mL HDPE bottle was rinsed once with 40mL of filtered seawater. All samples were stored onboard at -20ยฐC to preserve for land-based analysis. Analysis: All samples will be analyzed for total dissolved P (TDP) using the high temperature combustion magnesium sulfate oxidation techniques modified according to Monaghan and Ruttenberg [Monaghan1999]. DOP concentration will be reported as the difference between the TDP concentration and the PO4 concentration determined onboard by ODF. [Monaghan1999] Monaghan, E. J., and K. C. Ruttenberg. โ€œDissolved organic phosphorus in the coastal ocean: Reassessment of available methods and seasonal phosphorus profiles from the Eel River Shelf.โ€ Limnol. Oceanogr., 44(7), 1702-1714 (1999) 12 Nitrate ฮด15N and ฮด18O PIs * Angela Knapp (FSU) Technician * Kelly McCabe Nitrate (NO3^-) is the dominant dissolved inorganic form of nitrogen in the oceans. As a macro-nutrient, nitrate is depleted in the surface due to biological consumption and abundant in the ocean interior due to remineralization. The dual isotopes of NO3^- ฮด15N and ฮด18O) allow us to constrain the utilization and consumption processes controlling the nitrogen cycle within the South Pacific Subtropical Gyre. Nitrate ฮ”15N samples were collected from all depths at every two degrees of longitude. Two 60mL samples were collected from each niskin bottle fired in the shallowest six depths. One 30mL sample was taken from all other depths. All samples collected above 400 meters were hand filtered with a BD 60mL Luer-Lok tip syringe and a 25mm Puradisc 0.2ยฌยตm PES filter. The syringe and filter were rinsed with 40mL of seawater before each HDPE (both 60mL and 30mL) bottles were rinsed once with half their full volume of filtered seawater. The samples were stored onboard at -20ยฐC to preserve for land-based analysis. Analysis: The denitrifier method [Casciotti2002] [Sigman2001] will be used to analyze NO3^- ฮด15N and ฮด18O. Briefly, this method converts all NO3^- to nitrous oxide (N2O) via denitrifying bacteria before the sample is analyzed by an IRMS. [Casciotti2002] Casciotti, K. L., D. M. Sigman, M. G. Hastings, J. K. Bohlke, and A. Hilkert. โ€œMeasurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method.โ€ Anal. Chem., 74, 4905-4912 (2002) [Sigman2001] Sigman, D. M., K. L. Casciotti, M. Andreani, C. Barford, M. Calanter, and J. K. Bohlke. โ€œA bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater.โ€ Anal. Chem., 73, 4145-4153 (2001) 13 DISSOLVED ORGANIC CARBON AND TOTAL DISSOLVED NITROGEN PI * Craig Carlson (UCSB) Technician * Chance English Analysts * Keri Opalk * Elisa Halewood Support NSF 13.1 Project Goals The goal of the DOM project is to evaluate dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations along the P06 zonal transect (30 to 32.5ยฐS & 153ยฐE to 72ยฐW). During the P06 cruise Leg 1 (July - Aug 2017), casts were specifically targeted in order to overlap with the TCO2 sampling program. 13.2 Sampling DOC profiles were taken at approximately every other station from 26 of 36 niskin bottles ranging the full depth of the water column (68 stations; ~1800 DOC and 600 TDN samples. DOC samples were passed through an inline filter holding a combusted GF/F filter attached directly to the Niskin for samples in the top 500 m of each cast. This was done to eliminated particles larger than 0.7 ยตm from the sample. Samples from deeper depths were not filtered. Previous work has demonstrated that there is no resolvable difference between filtered and unfiltered samples in waters below the upper 500 m at the ยตmol kg^-1 resolution. All samples were rinsed 3 times with about 5 mL of seawater and collected into combusted 40 mL glass EPA vials. Samples were fixed with 50 ยฌยตL of 4N Hydrochloric acid and stored at 4ยฐC on board. Samples were shipped back to UCSB for analysis via high temperature combustion on Shimadzu TOC-V or TOC L analyzers. Sample Vials were prepared for this cruise by soaking in 10% Hydrochloric acid, followed by a 3 times rinse with DI water. The vials were then combusted at 450ยฐC for 4 hours to remove any organic matter. Vial caps were cleaned by soaking in DI water overnight, followed by a 3 times rinse with DI water and left out to dry. Sampling goals for this cruise were to continue high resolution, long term monitoring of DOC distribution throughout the water column, in order to help better understand biogeochemical cycling in global oceans. 13.3 Standard Operating Procedure for DOC Analyses- Carlson Lab UCSB DOC samples will be analyzed via high temperature combustion using a Shimadzu TOC-V or Shimadzu TOC-L at an in shore based laboratory at the University of California, Santa Barbara. The operating conditions of the Shimadzu TOC-V have been slightly modified from the manufacturer's model system. The condensation coil has been removed and the headspace of an internal water trap was reduced to minimize the system's dead space. The combustion tube contains 0.5 cm Pt pillows placed on top of Pt alumina beads to improve peak shape and to reduce alteration of combustion matrix throughout the run. CO2 free carrier gas is produced with a Whatmanยฎ gas generator [Carlson2010]. Samples are drawn into a 5 ml injection syringe and acidified with 2M HCL (1.5%) and sparged for 1.5 minutes with CO2 free gas Three to five replicate 100 ยตl of sample are injected into a combustion tube heated to 680ยฐC. The resulting gas stream is passed through several water and halide traps, including an added magnesium perchlorate trap. The CO2 in the carrier gas is analyzed with a non-dispersive infrared detector and the resulting peak area is integrated with Shimadzu chromatographic software. Injections continue until the at least three injections meet the specified range of a SD of 0.1 area counts, CV โ‰ค 2% or best 3 of 5 injections. Extensive conditioning of the combustion tube with repeated injections of low carbon water (LCW) and deep seawater is essential to minimize the machine blanks. After conditioning, the system blank is assessed with UV oxidized low carbon water. The system response is standardized daily with a four-point calibration curve of potassium hydrogen phthalate solution in LCW. All samples are systematically referenced against low carbon water and deep Sargasso Sea (2600 m) or Santa Barbara Channel (400 m) reference waters and surface Sargasso Sea or Santa Barbara Channel sea water every 6 - 8 analyses [Hansell1998]. The standard deviation of the deep and surface references analyzed throughout a run generally have a coefficient of variation ranging between 1-3% over the 3-7 independent analyses (number of references depends on size of the run). Daily reference waters were calibrated with DOC CRM provided by D. Hansell (University of Miami; [Hansell2005]). 13.4 DOC calculation average sample area - machine blank area ยตMC = โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” slope of std curve 13.5 Standard Operating Procedure for TDN analyses- Carlson Lab UCSB TDN samples were analyzed via high temperature combustion using a Shimadzu TOC-V with attached Shimadzu TNM1 unit at an in-shore based laboratory at the University of California, Santa Barbara. The operating conditions of the Shimadzu TOC-V were slightly modified from the manufacturer's model system. The condensation coil was removed and the headspace of an internal water trap was reduced to minimize the system's dead space. The combustion tube contained 0.5 cm Pt pillows placed on top of Pt alumina beads to improve peak shape and to reduce alteration of combustion matrix throughout the run. Carrier gas was produced with a Whatmanยฎ gas generator [Carlson2010] and ozone was generated by the TNM1 unit at 0.5L/min flow rate. Three to five replicate 100 ยตl of sample were injected at 130mL/min flow rate into the combustion tube heated to 680ยฐC, where the TN in the sample was converted to nitric oxide (NO). The resulting gas stream was passed through an electronic dehumidifier. The dried NO gas then reacted with ozone producing an excited chemiluminescence NO2 species [Walsh1989] and the fluorescence signal was detected with a Shimadzu TNMI chemiluminescence detector. The resulting peak area was integrated with Shimadzu chromatographic software. Injections continue until at least three injections meet the specified range of a SD of 0.1 area counts, CV โ‰ค2% or best 3 of 5 injections. Extensive conditioning of the combustion tube with repeated injections of low nitrogen water and deep seawater was essential to minimize the machine blanks. After conditioning, the system blank was assessed with UV oxidized low nitrogen water. The system response was standardized daily with a four-point calibration curve of potassium nitrate solution in blank water. All samples were systematically referenced against low nitrogen water and deep Sargasso Sea reference waters (2600 m) and surface Sargasso Sea water every 6 - 8 analyses [Hansell1998]. Daily reference waters were calibrated with deep CRM provided by D. Hansell (University of Miami; [Hansell2005]). Dissolved organic nitrogen (DON) concentrations are calculated as the difference between TDN and DIN. Samples with less than 10 ยตmol/kg DIN are most reliable estimates of DON. 13.6 TDN calculation average sample area - machine blank area ยตMN = โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” slope of std curve [Carlson2010] Carlson, C. A., D. A. Hansell, N. B. Nelson, D. A. Siegel, W. M. Smethie, S. Khatiwala, M. M. Meyers and E. Halewood 2010. Dissolved organic carbon export and subsequent remineralization in the mesopelagic and bathypelagic realms of the North Atlantic basin. Deep Sea Research II, 57: 1433-1445. [Hansell1998] Hansell, D.A. and C.A. Carlson 1998. Deep ocean gradients in the concentration of dissolved organic carbon. Nature, 395: 263-266. [Hansell2005] Hansell, D.A. 2005 Dissolved Organic Carbon Reference Material Program. EOS, 35:318-319. [Walsh1989] Walsh, T.W., 1989. Total dissolved nitrogen in seawater: a new high-temperature combustion method and a comparison with photo-oxidation. Mar. Chem., 26:295-311. 14 (14/13C) PI * Ann McNichol (WHOI) Technician * Chance English A total of 27 samples were collected from 24 stations along Leg 1 of the P06 zonal transect (30-32.5ยฐS & 153ยฐE to 72ยฐW). Samples were taken from only the surface bottle (~ 5m) at each station with approximately 2.5 degrees of spacing between each station. Duplicates were made at three separate stations. Samples were collected in 500 mL airtight glass bottles. Using silicone tubing, the flasks were rinsed 2 times with seawater from the surface niskin. While keeping the tubing at the bottom of the flask, the flask was filled and flushed by allowing it to overflow 1.5 times its volume. Once the sample was taken, about 10 mL of water was removed to create a headspace and 120 ยฌยตL of 50% saturated mercuric chloride solution was added to the sample. To avoid contamination, gloves were used when handling all sampling equipment and plastic bags were used to cover any surface where sampling or processing occurred. After each sample was taken, the glass stoppers and ground glass joint were dried and Apiezon-M grease was applied to ensure an airtight seal. Stoppers were secured with a large rubber band wrapped around the entire bottle. Samples were stored in AMS crates in the shipโ€™s dry laboratory. Samples were shipped to WHOI for analysis. The radiocarbon/DIC content of the seawater (DI14C) is measured by extracting the inorganic carbon as CO2 gas, converting the gas to graphite and then counting the number of 14C atoms in the sample directly using an accelerated mass spectrometer (AMS). Radiocarbon values will be reported as 14C using established procedures modified for AMS applications. The 13C/12C of the CO2 extracted from seawater is measured relative to the 13C/12C of a CO2 gas standard calibrated to the PDB standard using and isotope radio mass spectrometer (IRMS) at NOSAMS. 15 LADCP PI * Dr. Andreas Thurnherr Cruise Participant * Alma Carolina Castillo-Trujillo LADCP was collected during full depth CTD casts at all stations by Alma Carolina Castillo-Trujillo and Natalie Zielinski. Preliminary processing and QC was made on board by Alma Carolina Castillo- Trujillo. Approximately every 5 casts or when data was questionable post-processed data was sent to Andreas Thurnherr for further QC. 15.1 LADCP system configuration An upward-looking (UL) and a downward-looking (DL) ADCPs and a rechargeable battery were affixed to the rosette using custom brackets (Figure 1 and 2). The UL instrument was positioned ~5 inches over the top rosette ring while the DL instrument was positioned between Niskin bottles 4 and 6 and affixed through the brackets to the rosette bottom center bar. An external magnetometer/accelerometer package (independent measurement package; IMP) was installed on the rosette to collect additional pitch, roll and heading data. The instrument was removed from the rosette after station 13 after a leak was found in the pressure case. A star cable was used to connect both UL and DL LADCPs to the battery and deck/connection cables. While on deck, two communications and one power cable ran from the aft dry lab to the baltic room where the ctd package rested while on transit between stations. One of the power cables connected the battery to a battery charger while the second power cable connected the ADCPs through the star cable to a power supply. The communications cable connected the ADCPS to a MAC computer via a USB serial adapter which was used for communications to the instrument and data download. The LADCP acquisitions computer clock was synced to the master clock via the ship network system. Two different ADCP instruments were used during the cruise. The Teledyne RDI WHM150 (S/N:24544) as DL and the Teledyne RDI WHM300 (S/N:24997) as the UL. The battery package was a Deepsea Power and Light SB 48 V/16 A (S/N: 02126). All instruments were set up to record velocity data with 8 m bins and zero blanking distance. Staggered pinging was used to avoid previous ping interference. 15.2 Problems/Setup changes For stations 5 to 13 problems were due to a leak in the IMP pressure case. IMP was removed and replaced with a star cable after station 13. โ€ข Station 5: Unable to connect to LADCPs. Data was lost. โ€ข Station 6: Unable to connect to LADCPs. Data was lost. โ€ข Station 7: Unable to connect to UL instrument. Data for UL ADCP data was lost. โ€ข Station 8: Unable to connect to UL instrument. Data for UL ADCP data was lost. โ€ข Station 9: Unable to connect to UL instrument. Data for UL ADCP data was lost. โ€ข Station 10 to 13: Unable to connect to LADCPs. Data was lost. โ€ข Station 31: 2 UL files were created. โ€ข Station 37: 2 UL files were created. For stations 60, 63, 65, 77, 89 and 90 problems were due to a communication error in the Acquire software. After restarting computer and replacing the Keyspan serial-to-usb port, problem was resolved. โ€ข Station 60: Manually downloaded data. โ€ข Station 63: Manually downloaded data. โ€ข Station 65: Manually downloaded data, USB serial adapter was replaced. โ€ข Station 77: Manually downloaded data. 2 casts were made. Cast 1 was canceled at the surface due to bad weather. โ€ข Station 89: Manually downloaded data. โ€ข Station 90: Manually downloaded data. โ€ข Station 97: Broken beam 3. โ€ข Station 121: 2 casts were made. Cast 1 was canceled at ~600 m due to bad weather. โ€ข Station 126: 2 casts were made. Cast 1 was canceled at the surface due to bad weather. โ€ข Station 130: Due to a CTD altimetry problem, two casts were made and saved into one file. First cast was canceled after ~50m. Data was not downloaded between casts. DCP programming and data acquisition were carried out by Alma Carolina Castillo-Trujillo and Natalie Zielinski using the LDEO Acquire software running on a MAC computer. Prior to each cast, the corresponding command files were send to both the UL and DL ADCPs, communications were then terminated, deck cables disconnected and all connections were secured and sealed with dummy plugs. After the rosette was brought back up on desk following a cast, the communication and power cables were connected to the MAC computer. Data acquisition were terminated and files were downloaded with the corresponding command using the Acquire software. The battery was disconnected from the star cable and connected to a charger via a deck cable running from the the baltic room to the dry aft lab. The battery remained connected to the charger between stations. The battery pack was periodically vented manually to prevent pressure build up. Log files were kept for each cast with LADCP and CTD information to ensure all steps were made properly. 15.3 Data Processing and Quality Control The ADCP data was processed daily by AC. Castillo using the Matlab- based LDEO LADCP processing software version IX (1). Processing warnings and figures created through the software were reviewed for signs of anomalies such as rosette rotation and tilt, biased shear, agreement between LADCP and SADCP velocities, beam strength and range and ADCP distance to the sea bottom. Data was sent to Andreas Thurnherr every 5 stations or when questionable profiles were observed. Figure 3 and 4 show the preliminary results of zonal and meridional velocities for all the available stations. Maximum values reach up ~40 cm/s in the upper ~200 m. There is a relatively strong northward current (~15 cm/s) on the west side of the Kermadec Trench at -178 W. Vertical velocity weas also computed for the first 53 stations using the LADCP_w software V1.3 (1). Figure 5 shows a contour plot of vertical velocities on available stations. Typical values range at ~3 cm/s. Vertical propagating signals are seen throughout the transect. Further QC and post-processing of horizontal and vertical velocities at all available stations will be done by Andreas Thurnherr at LDEO post-cruise. Available for download at http://www.ldeo.columbia.edu/LADCP [image]Downward looking ADCP [image]Upward looking ADCP [image]LADCP derived zonal velocities observed from available stations during P06-leg1. Grey lines indicate density contours calculated from CTD observations. [image]LADCP derived meridional velocities observed from available stations during P06-leg1. Grey lines indicate density contours calculated from CTD observations. [image]Vertical velocities for stations 1 to 53 during P06-leg1 calculated with the LADCP_w software V1.3 using LADCP and CTD observations. 16 Chipods PI * Jonathan Nash Cruise Participant * Ratnaksha Lele 16.1 Overview Chipods are instrument packages that measure turbulence and mixing in the ocean. Specifically, they are used to compute turbulent diffusivity of heat (ฮš) which is inferred from measuring dissipation rate of temperature variance (ฯ‡) from a shipboard CTD. Chipods are self-contained, robust and record temperature and derivative signals from FP07 thermistors at 100 Hz; they also record sensor motion at the same sampling rate. Details of the measurement and our methods for processing chi can be found in Moum and Nash [2009] (Moum, J., and J. Nash, Mixing Measurements on an Equatorial Ocean Mooring, Journal of Atmospheric and Oceanic Technology, 26(2), 317-336, 2009). In an effort to expand our global coverage of deep ocean turbulence measurements, the ocean mixing group at Oregon State University has supported chipod measurements on all of the major global repeat hydrography cruises since Dec 2013. 16.2 System Configuration and Sampling Three chipods were mounted on the rosette to measure temperature (T), its time derivative (dT/dt), and x and z (horizontal and vertical) accelerations at a sampling rate of 100 Hz. Two chipods were oriented such that their sensors pointed upward. The third one was pointed downward. The up-looking sensors were positioned higher than the Niskin bottles on the rosette in order to avoid measuring turbulence generated by flow around the rosette and/or its wake while its profiling speed oscillates as a result of swell-induced ship-heave. The down-looking sensors were positioned as far from the frame as possible and as close to the leading edge of the rosette during descent as possible to avoid measuring turbulence generated by the rosette frame and lowered ADCP. [image]Chipod pressure case attached on the rosette Logger Board SN Pressure Case SN Up/Down Looker Cast Used โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” 2025 Ti 44-7 Up 1-143 2030 Ti 44-11 Up 1-107 2032 Ti 44-11 Down 1-143 2027 Ti 44-11 Up 112-143 16.3 Data The chipods were turned on by connecting the sensors to the pressure case at the beginning of the cruise. They continuously recorded data until the end of the leg. Data was uploaded onto the computer once every day to ensure proper functioning and data collection. SN2030 was replaced by SN2027 before cast 112 due to problems with file acquisition and communicating with the device possibly due to a memory card issue. SN2030 memory card and batteries were replaced soon after. [image]A typical plot of chipod raw data 17 FLOAT DEPLOYMENTS During leg 1 of the GO-SHIP P06 cruise (P06W), a total of 11 profiling floats were deployed, which were part of several programs: 4 UW Argo, 2 SIO SOLO II, 3 SIO Deep SOLO and 2 biogeochemical SOCCOM floats. Co- chief scientist Isa Rosso (postdoc at SIO and SOCCOM personnel) was responsible for all deployments, recording and communicating their deployment details to the various PIs of the programs. The assistance from the ASC marine technicians was necessary for all deployments, first because it was required for any operation on the back deck, and second in order to reduce any possible difficulties with the floatsโ€™ deployment. Each deployment occurred with the use of line strung to the float, with one end of the line tied to a cleat and the other held by the technician. Deployments were always done on departure from a CTD station while the ship was steaming at 1 knot. Before the deployment, the marine technician communicated with the bridge to disengage the propeller on the side of the deployment, in order to avoid any risk of having the float going through the propeller. The three students working on the opposite shift to Isa Rosso also assisted with the deployments. A 10-day cycle is set for the UW Argo, SOLO II, and SOCCOM floats: after an initial dive to a parking depth of 1000m, the floats drift for 10 days with the ocean currents at this depth; after a subsequent dive to 2000m, the floats then ascend to the surface, during which data are collected. The 2000m-surface data profiles are then sent to shore via satellite, using an antenna located at the top of the float. Measurements comprehend temperature, salinity, pressure and additional biogeochemical measurements for the SOCCOM type. The SIO Deep SOLO profiling floats have a different cycle: they dive down to the full ocean depth and drift at 5000 dbar, or 500 dbar shallower than the bottom, with a cycle of approximately 15 days, in order to balance data collection with battery life. Each of these floats was self-activating, so no initial operations where required before their deployment to activate them, except for the case of Deep SOLO floats for which John Gilson sent some commands few hours before their deployment. In the following, each float program is discussed. 17.1 SOCCOM floats PIs * Steve Riser * Ken Johnson * Lynne Talley Two biogeochemical floats have been deployed, as part of the โ€œSouthern Ocean Carbon and Climate Observations and Modelingโ€ project (SOCCOM). SOCCOM is a U.S. project sponsored by NSF that focuses on carbon and climate in the Southern Ocean. Its goal is to deepen our knowledge of the processes that regulate the carbon export in the Southern Ocean. So far, SOCCOM has 82 active floats, and the data are available to the public at http://soccom.princeton.edu/content/float-data. The floats are equipped with CTD, oxygen (Anderaa optode 4330), nitrate (MBARI/ISUS), FLBB bio-optical (Wetlabs) and pH (Deep-Sea DuraFET) sensors. Data acquisition is made available through Iridium Satellite communication and GPS. Rick Rupan and Andrew Meyer (UW) tested each float (for both leg 1 and leg 2 of the P06 occupation) at the beginning of the voyage during the port call in Sydney, Australia. They found a malfunction on one of the floats assigned to leg 2, and this float has been sent back to UW for investigation and repair. Before the deployment of each float, the fluorometer/backscatter and the pH sensors were carefully cleaned using lens paper, 99% isopropyl alcohol and DI water. Co-chief scientist Isa Rosso, SOCCOM personnel responsible for the floats during this voyage, together with the ASC marine technician Jennie Mowatt, were in charge of all SOCCOM float deployments. Additional assistance was received by ASC marine technician Paul Savoy. The procedure required the use of a line strung through the deployment collar of the float. Each deployment occurred on the starboard side, mid-ship, while the ship was steaming at no more than 1 kn. No issues were encountered during the deployments. However, during the last of the SOCCOM float releases (#12372), a swell brought the float back up to ~1m out of the water, but fortunately no sensors hit the ship. The deployments occurred after the completion of the CTD station that was chosen to be the closest to the planned deployment location and had a bottom depth greater than 2500m. Samples for HPLC and POC analyses were taken from the Niskin bottles, tripped as duplicates, at the surface and at the chlorophyll maxima depths. These samples will be sent to the U.S., where NASA (HPLC) and UCSB (POC) groups will perform the analyses. On board, only the filtration of the samples was required. Full-depth samples of other ocean properties (salts, pH, nitrate, oxygen) were collected and analysed by the different groups on board, in order to calibrate the floatsโ€™ sensors. In particular, pH samples were collected and analysed by personnel from SIO, Dickson lab; dissolved inorganic carbon samples by personnel from AOML and PMEL; oxygen, nitrate and salinity samples by the ODF group at SIO. After the deployment, Isa Rosso recorded the details and sent them to the SOCCOM PIs. The location and date of the float deployments are indicated in the table below, with hull and serial numbers, list of parameters measured by the floats and the CTD cast at the location of deployment. Both floats have reported their first profiles and their sensors are working well. The figure below shows an example of profiles for the float #12380. Table 17.1: summary of the deployment details of the SOCCOM floats Hull Lon Lat Date and Parameters P06 Deployers # Time sta- (UTC) tion โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” Apex 174ยฐ50.45'W 32ยฐ30.08'S 2017-07-28 CTD, oxygen, 99 Isa Rosso and 12380 23:43 nitrate, pH, Jennie Mowatt fluorescence and backscattering Apex 154ยฐ56.01'W 32ยฐ29.97'S 2017-08-10 CTD, oxygen, 134 Isa Rosso and 12372 17:05 nitrate, pH, Jennie Mowatt fluorescence and backscattering [image]pH, oxygen, temperature and nitrate depth profiles for float Apex 12380 17.2 SIO floats PIs * Dean Roemmich * John Gilson 2 SIO SOLO II floats and 3 SIO Deep SOLO were deployed during the cruise. The SIO SOLO II are part of a global 3ยฐx3ยฐ array, while the Deep SOLO are part of the deep array, whose target is to have a float every 5ยฐx5ยฐ. Both types of floats are programmed to do a first dive, and to come back to the surface after only hour. The data of this first dive are used by the SIO team to check that the float is working correctly. We have received confirmation that all the floats have reported correctly after 1 hour, and their data look good (the Figure below shows an example for the float SIO SOLO II #8527). [image]SIO #8527 SOLO II profiles after 1 hour from the deployment These floats were deployed in their original bio-degradable cardboard boxes, as requested, in order to prevent any damage. Two bands of soluble PVA tape were placed around the box, in order to hold it together. Four straps were attached around the box, connected to a water release mechanism (a metal cylinder) at the bottom and with four trailing loops on the top. The deployment line was slipped through the trailing loops at the top, and then secured on the other end to a cleat. The deployments went all perfectly, except for the float Deep SOLO #6032: during its deployment, when still being lowered to the water, the release opened unexpectedly and the package dropped down from about 50cm above the ocean surface. The float did not, fortunately, report any damage, as we have received confirmation from John Gilson (SIO) that the float activated and sent good data after its first test cast. After each deployment, the details were recorded by the scientist responsible for the deployment (either Isa Rosso or a CTD watchstander) and sent to John Gilson by co-chief scientist Isa Rosso. The location and date of the SIO float deployments are indicated in the table below, with serial numbers, CTD cast at the location of deployment and name of the personnel who deployed the floats. Table 17.2: summary of the deployment details of the 2 SIO SOLO II and 3 Deep SOLO floats Hull Lon Lat Date and P06 Deployers # Time sta- (UTC) tion โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” SIO SOLO 163ยฐ55.196'E 30ยฐ04.88'S 2017-07-12 37 Isa Rosso and Jennie Mowatt II 8527 01:25 SIO SOLO 178ยฐ18.421'E 32ยฐ53.84'S 2017-07-24 80 Kimberly Gottschalk and II 8555 12:51 Michael Tepperrassmussen SIO Deep 167ยฐ47.336'W 32ยฐ29.99'S 2017-08-02 115 Isa Rosso and Jennie Mowatt SOLO 6030 15:18 SIO Deep 159ยฐ43.06'W 32ยฐ30.15'S 2017-08-08 127 Maxime Duchet and SOLO 6031 08:33 Michael Tepperrassmussen SIO Deep 152ยฐ15.50'W 32ยฐ30.00'S 2017-08-11 138 Ratnaksha Lele and Paul Savoy SOLO 6032 23:55 17.3 UW floats PI Steve Riser 4 UW floats have been deployed during P06 leg 1, as part of the global Argo array. Rick Rupan and Andrew Meyer had tested the floats, during the port call in Sydney, Australia. The floats were all successfully deployed, with no issues. After the deployment, the details were recorded by the scientist responsible for the deployment and sent to Steve Riser, Dana Swift and Rick Rupan by co-chief scientist Isa Rosso. Date, time, location of the deployment, CTD cast associated with the deployments and the name of the deployers are reported in the Table below. Table 17.3: summary of the deployment details of the 4 UW floats Hull Lon Lat Date and P06 Deployers # Time sta- (UTC) tion โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” UW #12471 155ยฐ00.15'E 30ยฐ04.91'S 2017-07-06 12 Isa Rosso and Jennie Mowatt 22:26 UW #12645 158ยฐ40.66'E 30ยฐ04.99โ€™S 2017-07-09 25 Rebecca Beadling and 20:21 Jennie Mowatt UW #12638 175ยฐ00.04'E 30ยฐ04.78โ€™S 2017-07-10 73 Kimberly Gottschalk and 04:03 Michael Tepperrassmussen UW #12447 148ยฐ54.40'W 32ยฐ29.94โ€™S 2017-08-13 143 Isa Rosso and Jennie Mowatt 15:24 18 DRIFTER DEPLOYMENTS PI * Shaun Dolk (*AOML*) Fourteen drifters were deployed on P06W for the Global Drifter Program. The deployers were split between the night and the day shifts: Isa Rosso (co-chief scientist), Sabine Mecking (chief scientist) and the CTD watchstanders of each shift helped with the deployment. Secondary assistance was provided by ASC Marine Technicians Jennie Mowatt (night shift), Michael Tepperrassmussen (day shift) and Paul Savoy (day/night shift). The simple deployment process involved: (1) removing the plastic wrapping from the drifter; (2) carrying the drifter to the back deck; (3) deployment of the drifter, after received confirmation from the bridge; (4) recoding of the deployment details. In case two deployments were required at the same location, the drifter release occurred with 30 seconds of distance between each other, in order to avoid any entanglement amongst the drifters' drogues. After the deployment, the scientist responsible for the operation recorded the details from the monitor in the wet lab, wrote them in the log sheet and Isa Rosso (co-chief scientist) or Sabine Mecking (chief scientist) sent the details to Shaun Dolk at AOML. The Table below reports the details for each deployment. Table 18.1: Table of deployments Drifter # Date (UTC) Lat Lon Deployers โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” 64829450 2017-07-11 30ยฐ04.91'S 163ยฐ29.98'E Isa Rosso and Jennie Mowatt 20:42 64828550 2017-07-29 32ยฐ30.02'S 173ยฐ29.86'W Isa Rosso and Jennie Mowatt 16:45 64829010 2017-07-29 32ยฐ30.02'S 173ยฐ29.86'W Isa Rosso and Jennie Mowatt 16:45 64829500 2017-08-01 32ยฐ29.95'S 170ยฐ00.31'W Sabine Mecking and 10:23 Michael Tepperrassmussen 64828540 2017-08-02 32ยฐ29.96'S 167ยฐ07.09'W Isa Rosso and Jennie Mowatt 23:13 64829170 2017-08-02 32ยฐ29.96'S 167ยฐ07.09'W Isa Rosso and Jennie Mowatt 23:13 64829460 2017-08-04 32ยฐ29.74'S 164ยฐ00.17'W Kimberly Gottschalk and 09:02 Michael Tepperrassmussen 64828510 2017-08-07 32ยฐ29.68'S 160ยฐ59.91'W Sabine Mecking and 09:21 Maxime Duchet 64828530 2017-08-07 32ยฐ29.68'S 160ยฐ59.91'W Kimberly Gottschalk and 09:21 Michael Tepperrassmussen 64828470 2017-08-09 32ยฐ30.23'S 158ยฐ00.00'W Ratnaksha Lele and 03:04 Paul Savoy 64829030 2017-08-10 32ยฐ29.98'S 155ยฐ01.14'W Rebecca Beadling and 12:36 Jennie Mowatt 64829510 2017-08-10 32ยฐ29.98'S 155ยฐ01.14'W Natalie Zielinski 12:36 and Jennie Mowatt 64829540 2017-08-12 32ยฐ30.04'S 152ยฐ00.00'W Maxime Duchet and 01:18 Michael Tepperrassmussen 64829400 2017-08-13 32ยฐ30.00'S 150ยฐ00.50'W Kimberly Gottschalk and 01:00 Michael Tepperrassmussen 19 STUDENT STATEMENTS 19.1 Rebecca L. Beadling I applied to participate on leg 1 of the U.S. GO-SHIP P06 cruise to gain experience in observational oceanography, to participate in the data collection myself and to learn about the techniques used including CTD deployment and measurements, deployment of floats and drifters, and the collection of water samples for analysis. I also participated in this cruise as a member of the Southern Ocean Carbon and Climate Observations and Modelling (SOCCOM) team, and was able to participate in the deployment of the SOCCOM floats along with my CTD watchstander responsibilities. My work at the University of Arizona has focused on carrying out modeling experiments and analyzing model output to gain a deeper understanding of ocean circulation in the North Atlantic Ocean. Specifically my research as focused on the Northern Hemisphere Atlantic Meridional Overturning Circulation, and how this large scale circulation is projected to change into the future. Analyzing the results from modeling experiments requires a comprehensive understanding of geophysical fluid dynamics, knowledge of the framework of models, knowledge of both the atmospheric and oceanic circulation at the global scale, and an understanding of how these systems are observed in reality. It is this last piece that I felt was completely lacking from my understanding of oceanography, and the most critical to being able to make successful model to observation comparisons. After participation as a CTD watchstander on this cruise and through in-depth conversations with other scientists on board, I am walking away with a detailed knowledge of observational techniques and better strategies to bridge the gap from models to observations. In addition to my role as a CTD watchstander I also served as the primary alkalinity sampler on my shift, collecting alkalinity samples to be processed following each CTD recovery. Furthermore, on this cruise spent time learning the Python programming language and plotted the underway Acoustic Doppler Current Profiler data from the cruise to look at the currents in the top 1000 meters as we transited. I also contributed multiple times to the cruise blog (usgoship-p062017.blogsplot.com) and my own personal blog focused on science communication to a broader audience (beadlingatsea.wordpress.com). My experiences and knowledge gained on this cruise will prove to be invaluable to advancing in my field, and I plan to remain in contact with those on board for future research collaborations. 19.2 Maxime Duchet Pour changer, en voici un ecrit en francais clavier qwerty, vous excuserez les accents. Le travail est finalement assez simple et repetitif. Chaque jour, on effectue en moyenne 2 a 3 "cast", en fonction de la profondeur de la station. Le deroulement est chaque fois le meme: 1. On met le CTD (plus communemment appele rosetta) dans l'eau. On se trouve alors derriere plusieurs ecrans : un ordinateur qui enregistre les mesurements effectues par la CTD (capteurs de temperature, salinite..), un qui nous indique la profondeur et la tension du fil retenant la structure de 36 bouteilles, et enfin un ecran pour voir le winch tourner. On passe des appels radio a la "Baltic room" ou se trouvent les winch operateurs pour indiquer la vitesse de descente, stopper la rosette a 10m du fond, et indiaquer les differerentes profondeurs auxquelles s'arreter lors de la remontee. On ferme les bouteilles et note quelques informations. A surveiller: tension ne dois pas faire de sauts ni etre negative, bottom approach ne pas crasher la rosette, ne pas oublier de fermer une bouteille. 2. Une fois la rosette sur le deck, on effectue des prelevements selon divers procedes en fonction des parametres mesures. En gros, on remplie des bouteilles d'eau. 3. On prepare la rosette: on ouvre les bouteilles, on les vide, on tend les fils de nilon, on nettoie les capteurs. 4. Si on a de la chance, la prochaine station est dans 2h et on a le temps de chiller au ping pong ou dans la lounge. Le plus important : prendre du plaisir en mer et profiter de lโ€™experience humaine. PS : si vous prevoyez de participer aux 4 repas journaliers, nโ€™oubliez pas la gym, votre ventre appreciera. 19.3 Kimberly Gottschalk My first experience at sea, aboard the RVIB Palmer, was a fantastic voyage across the South Pacific. Serving as a CTD Watchstander for the P06W provided me with invaluable insight and working knowledge of how data is collected and processed at sea. Over the course of the past six weeks I have developed a greater appreciation of the work of the science party and an understanding of why gaps in data may occur on open ocean lines. The work of a CTD student required a keen eye for detail and communication for successful operation. In my off time I have had the pleasure of attending science talks, speaking with others about their work, helping with sampling, and plot creation. Between monitoring the rosette during casts the watchstanders had the opportunity to hold a journal club focusing on processes and water masses along our line - a wonderful learning experience! As the cruise comes to a wrap, I'll miss being at sea. The view of a sunset over the ocean, watching an Orca swim under our bow while on station, even the gentle rolling of the ship - are all things I will not soon forget. This may have been my first time at sea, but it will not be my last. 19.4 Ratnaksha Lele Being on board the RVIB Nathaniel B. Palmer for GO-SHIP P06 has been an experience that I will cherish for the rest of my life! This was my first time on a multi-week research cruise, and I was rather excited to leave the worries of the world behind as we set our sights to the horizon to our east in Sydney. My job as CTD-watchstander was primarily to prepare the rosette for each deployment and monitor the cast in the computer lab to ensure that the cast went smoothly, keeping an eye on instrument displays and firing the bottles at the assigned depths. It was exciting to see the CTD profiles on the computer in real time and be able to identify (debate) different water masses in the South Pacific which I very recently studied for my first year exams at SIO. Once the rosette was back on deck after the cast, I thoroughly enjoyed my duties as Sample Cop, bringing necessary order to the chaos of sampling. I was also involved in downloading data from Chi-pods (instruments that measure turbulent mixing) and troubleshooting through glitches if and when they occurred. The cruise has helped me appreciate the behind the scenes effort put into every CTD cast by the science team, and the painstaking effort required to collect and measure samples for the consumption of researchers worldwide. I hope to use the data collected on this cruise and previous P06 cruises to quantify changes in abyssal water masses in the South Pacific basin as part of my PhD research at SIO. I'm grateful to the GO-SHIP program for providing me with this wonderful opportunity and hope to continue to participate and contribute to future cruises as well. 19.5 Kelly McCabe [image] I want to thank GO-SHIP for providing me with this opportunity to assist the chlorofluorocarbon (CFC) teamโ€šร„รฎJim Happell and David Cooperโ€šร„รฎwith sampling the CTD and onboard sample processing. As transient tracers, CFCs are a standard measurement on GO-SHIP cruises. Measuring CFC concentrations as well as sulfur hexafluoride (SF6), another tracer, allows physical and chemical oceanographers alike to understand ocean circulation and the distinct chemical characteristics of water masses. This is extremely valuable for understanding the global oceans and their role in mitigating climate. I am now able to collect CFC samples, successfully run them on a gas chromatograph, and interpret their gas chromatograms. Additionally, I created and analyzed CFC depth profiles in ODV. I can now identify distinct water masses based on a specific CFC signature such as Antarctic Bottom Water found in the Kermadec trench. In an attempt to objectively map CFC depth profiles, I also began coding in python and strengthened my MATlab coding abilities. I owe an additional thanks to GO-SHIP for helping support my PhD studies. In addition to my CFC responsibilities, I collected 375 samples for dissolved organic phosphorus analysis. All samples were filtered and stored frozen to preserve for land based analyses. These samples will greatly increase the special coverage of DOP data within the western Pacific, a previously under-sampled region. I am grateful to have had the opportunity to assist the GO-SHIP CFC team as well as contribute a new measurement. I hope to continue to work with the GO- SHIP program in the future. 19.6 Natalie Zielinski The ability to sail as a student aboard the GO-SHIP NPB1706 cruise from Sydney to Papeete has granted me the invaluable opportunity for hands-on learning and networking with leading scientists in oceanography. Originally hired on as a Conductivity Temperature Depth (CTD) Watch Stander, I also took on the responsibility of running the Lowered Acoustic Current Doppler Profiler (LADCP) during the night shift. Having prior experience at sea aboard the NBP, I felt right at home with the 12 on - 12 off shift schedule and adjusted well to having breakfast for lunch everyday. The need for additional personnel during water sampling also allowed me to learn how to sample alkalinity, nutrients and salts from the Nisken bottles, a task that I was happy to be a part of since it provided time to chat with my fellow scientists and to take part in unrestricted singing to the various songs we listened to. As the sole LADCP contact for the night shift, I was responsible for turning the instrument on and off, recharging the battery, and ensuring that the data were downloaded and backed up to the computer. This meant revisiting my Unix coding skills as the ADCP software is strictly run with Unix. During each descent, I join my fellow student colleague, Rebecca Beadling from the University of Arizona, at the CTD monitor station to oversee the deployment and trigger Nisken bottles on the way up. Forced to sit together for 4 to 5 hours, we took advantage of the time by starting a Python Club instructed by wonderful, Co-Chief Scientist Dr. Isabella Rosso where we learned to code, expanded our capabilities with the guitar, read different papers and novels, and shared our life experiences for personal growth. I could not have asked for a better team to be a part of, with the addition of all the nightshift personnel including Technician Kelsey Volgel from Scripps who was another assiduous member of our Python Club. [image]The hardworking and also fun night shift science party. Long live Chuckโ€™s Boots I also took part in some preliminary analysis for the cruise by drafting cross-sections of potential temperature, salinity, density, and calculated geostrophic velocity to be compared to those generated by Chief Scientist Dr. Sabine Mecking. The geostrophic velocities I generated were also compared to measured LADCP circulation for initial insight into the general circulation, particularly in the bathymetrically constrained areas closer to Australia. Later in the cruise while we were experiencing some rather unruly weather that prevented deployment of the CTD, Dr. Mecking asked me to give a science talk. Thrilled at the opportunity to practice my scientific speaking skills and discuss results from my Masterโ€™s degree, I happily accepted. I also wrote a post for the official NBP1706 Blog run by Co- Chief Scientist Dr. Isabella Rosso about my responsibilities with the ADCP on the night shift that can be found at http://usgoship-p062017.blogspot.com. [image]Cross-section of potential temperature for stations 01 to 75. I can't begin to describe how thankful I am for US GO-SHIP and the opportunity to sail as a student. I have been able to advance my observing, descriptive, and analytical skills as an aspiring young professional in oceanography, as well as to engage with outstanding professional scientist and technicians. I have grown professionally and personally from this experience, making memories and initiating relationships that will help drive my career. Iโ€™m particularly grateful for Dr. Sabine Mecking who took the time to get to know each student, encouraged our participation in all aspects of data collection, and was a rigorous ping-pong competitor, for Dr. Isabella Rosso and her ability to reignite my passion for scientific research, her motivation to believe in myself, and professional counsel as I transition from being a student to a career in oceanography and ocean engineering, for Mr. John Calderwood whose skills as a technician extended to the 3D printer, and for Mr. Barry Bjork whom with I spent a countless number of hours tackling cross-word puzzles and inventing new words. I will forever be grateful for this experience and hope to remain affiliated to the program through consideration for additional ocean-going positions in the future. 2017 P6 GO SHIP Repeat Hydrography Section LADCP Post-Cruise QC Report A.M. Thurnherr December 15, 2017 Figure 1: Cross-Pacific zonal section of p0, a measure of finescale (100{320m vertical wavelength) Vertical Kinetic Energy (VKE), along 32ยฐS derived from the vertical LADCP velocities collected during the 2017 occupation of the GO- SHIP P6 section; the orange contours show neutral density from uncalibrated CTD data. 1 Summary This report describes the results from the post-cruise quality control of the LADCP data collected during the two legs of the 2017 P6 GO-SHIP (CLIVAR repeat hydrography) cruise on the UNOLS R/V Nathaniel B. Palmer. Using two ADCPs installed on the hydrographic rosette (Section 2), one looking downward (DL) and the other upward (UL), full-depth profiles of all three components of the oceanic velocity field were collected at most stations. Entirely different methods are used for processing LADCP/CTD data for horizontal and vertical velocity, requiring separate QC (Sections 3 and 4, respectively). Main Findings: 1) There is good overall agreement (<โˆ†u(rms)>โ‰ˆ4 cmยทs^(-1)) between the independent upper-ocean horizontal velocity measurements from the LADCP and SADCP systems, indicating that the LADCP-derived horizontal velocities from the 2017 re- occupation of the P6 repeat-hydrography line are of excellent quality. 2) Based on correlations between the independent vertical velocity measurements provided by the two ADCPs, the LADCP-derived w(ocean) profiles are of high quality as well. 2 Instruments and Data Acquisition During the first (profiles^(1) 1-143) and second (144-250) cruise legs, Alma Castillo Trujillo and Elizabeth Simons, respectively, were responsible for LADCP data acquisition and shipboard QC. Additionally, the processing figures from every 5th profile and from profiles with suspected problems were sent to Thurnherr for additional checks. Two different ADCP instruments were used during this cruise: the WHM15O #24544 as down-looker (DL) and the WHM300 #24497 as uplooker (UL). Initially (stations 1{13) the ADCPs were mounted on the rosette together with the "IMP" magnetometer/ accelerometer package that also serves as connection between the instruments and the battery. Almost immediately there were intermittent but frequent communications problems that were eventually traced to a leak in the IMP pressure case. As a result there are insufficient LADCP data for processing the profiles of stations 6 and 10- 13. On station 14 the IMP was replaced with a TRDI star cable and there are processable LADCP data from all remaining stations. However, intermittent communications problems continued during the entire cruise. The resulting profiles with multiple data files were processed with the largest files only. Five out of the final profiles (9, 60, 183, 200 and 221) were processed without any valid UL data. During profile 97 beam #3 of the DL ADCP failed. Because the performance of the instrument remained otherwise good, because no spare WM150 was available, and because the range of the WH300 uplooker was marginal in that region of relatively weak acoustic backscatter it was decided to continue data acquisition without replacing the ADCP with the bad beam with a 300 kHz instrument. The UL performed well throughout the entire cruise. Both ADCPs were set up to record velocity data with 8 m pulses/bins and zero blanking. Staggered pinging was used to avoid previous ping interference, which is particularly important for 150 kHz instruments. See cruise report for additional information. The left panel of Figure 2 shows the maximum profile depths. The topography of the first part of the cruise (the first 100 stations or so) is characterized by significant roughness in the Coral Sea and across a backarc basin just north of New Zealand. After crossing the deep Kermadec Trench around station 100 the seafloor becomes much smoother and rises gradually toward the EPR crest near station 188 before descending into the Chile Basin and, finally, rising again at the South American continental slope. Except for the three profiles from stations 93, 94 and 119, which were located in water deeper than 6000 m, bottom-track information is available for all profiles. The right panel of Figure 2 shows the number of rotations experienced by the rosette. The fact that the instrument rotated primarily counterclockwise during the downcasts and clockwise during the upcasts with approximately equal number of rotations suggests that there was comparatively little stress on the wire during this cruise. LADCP data quality is sensitively dependent on instrument range (Figure 3, left panel), which depends on the acoustic scattering environment. During the second half of the P6 cruise, acoustic backscatter was quite weak, with WH300 ranges below 65 m (an empirical limit for good horizontal-velocity profiles collected with single-ADCP systems) in most profiles after station 90 or so. The problem was compounded by a DL beam going bad on station 97, causing a significant reduction in instrument range, but the range of the 3-beam 150 kHz ADCP nevertheless remained above the 4-beam range of the 300 kHz UL for the remainder of the cruise, and the combined range of the two ADCPs was greater than 80 m in all dual-head profiles. Since the DL-only profiles (9, 60, 183, 200 and 221) all have ranges greater than 65 m, too, all P6 LADCP profiles are expected to yield good horizontal velocities. โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€” (1) LADCP profile numbers, which are equal to the CTD station numbers of this cruise, are used throughout in this report. The LADCP data distribution contains the file STATIONNUMBERS.nc, which associates LADCP profile numbers with CTD station and cast numbers. The CTD station and cast numbers are also printed in the titles of all diagnostic figures produced by the LDEO IX software. Figure 2: Profiling parameters. Left panel: Maximum depth. Right panel: Net package rotations. Figure 3: Left panel: Instrument range. Right panel: rms acceleration due to vessel heave (sea state). Package motion due to surface waves (sea state) is also known to affect LADCP data quality; in the right panel of Figure 3 sea state is quantified as the rms vertical package acceleration. Calm seas are typically associated with accelerations below 0.2mยทs^(-2) or so, implying significant wave-related package motion roughly in the middle third of the cruise. For context, the peak values around 0.35mยทs^(-2) are small compared to values from the Southern Ocean, which frequently exceed 0.4mยทs^(-2), indicating that sea state is not expected to have a strong detrimental effect on the quality of the P6 LADCP profiles. Figure 4: rms LADCP-SADCP horizontal velocity differences; low values indicate good agreement. 3 Horizontal Velocity The overall quality of the horizontal LADCP velocities is assessed by processing all profiles with the velocity-inversion method (LDEO IX 13 software), using the bottom- track (BT) and ship-drift (GPS) constraints and comparing the resulting LADCP velocities near the sea surface to the corresponding SADCP velocities. Based on data from other cruises, high-quality LADCP and SADCP velocities typically agree within 3- 6 cmยทs^(-1) when averaged over a few profiles. The data from the 2017 P6 occupation clearly fit this criterion (Figure 4). Only in the middle of the section, roughly between profiles 90 and 170, are there velocity discrepancies around 6 cmยทs^(-1), and the number of profiles with significantly higher discrepancies is small. Both low acoustic backscatter and sea state likely contributed to this pattern (Figure 3). Diagnostic plots were inspected from all profiles with velocity discrepancies exceeding 6 cmยทs^(-1), but no data anomalies were found. For final horizontal-velocity processing, the LADCP data were re-processed with all available referencing constraints, including the SADCP velocities. As a result, the final velocity uncertainties are smaller than the discrepancies shown in Figure 4, at least for the profiles with errors above 3 cmยทs^(-1), which is the nominal accuracy of horizontal velocity from high-quality LADCP profiles. In summary, the quality of the final processed horizontal velocities derived from the 2017 P18 LADCP data is excellent. (Possible exceptions are profiles 1 and 2, both short and shallow casts where the seabed was not detected correctly and for which no good SADCP data are available. There are no indications that the resulting horizontal velocity profiles, referenced with GPS data alone, are bad, however, and they are included in the archive.) Figure 5: Left panel: Correlation coefficient of DL/UL vertical velocity correlation vs. profile number, averaged in groups of 10 profiles with error bars from bootstrapping. Right Panel: Vertical-velocity signal (red; rms w) and noise (blue; rms DL/UL regression residuals scaled by 2^(-0.5)) vs. profile number. Data from the uppermost 300m are excluded. 4 Vertical Velocity In order to process the LADCP data for vertical ocean velocity the LADCP w software, version 1.4, was used. In addition to high-quality velocity data from the ADCPs, vertical-velocity processing also requires 24 Hz CTD time series with very few or no missing scans. In contrast to other recent GO-SHIP cruises, there are no indication for CTD data transmission problems during P6, attesting to the high quality of the CTD winch system on the Palmer. There are vertical-velocity profiles from all P6 stations with valid LADCP data. Dissipation estimates from a finestructure parameterization method (Thurnherr et al., GRL 2015) are available from all stations except those without valid LADCP data (6 & 10{13) and two stations at both ends of the section (1, 2, 249, 250), which are not deep enough for the spectral method to be applied. In contrast to LADCP-derived horizontal velocity, the two w measurements at a given depth (from the DL and UL ADCP) are largely^(2) independent. Diagnostics based on linear regressions between UL vs. DL-derived w are therefore useful measures of profile quality. The left panel of Figure 5 shows the resulting correlation coefficients for the P6 LADCP data below 300 m, calculated from w(ocean) profiles processed at the default 40m vertical resolution. Based on experience with other data sets, high-quality LADCP profiles typically have DL-UL correlation coefficients above 0.3 when averaged over a few profiles. The P6 LADCP profiles clearly fit this criterion - the apparent outlier group with correlation coefficients consistently above 0.5 are profiles 81{89 crossing the Havre Trough, where the highest VKE levels were observed on this cruise. The right panel of Figure 5 shows the vertical velocity signal and noise levels for all dual-head profiles. The red bars show profile-averaged w(ocean) below 300 m. (LADCP vertical velocity measurements near the surface are often contaminated by biological effects.) The blue bars show the corresponding rms noise estimates, defined here as the DL-UL regression residuals scaled by 1/โˆš2. Based on experience with other data sets, high-quality LADCP w profiles typically have residual noise levels in the range 0.003-0.006 mยทs^(-1) . The P6 LADCP profiles clearly fit this criterion, too. The profile-averaged Vertical Kinetic Energy (VKE) levels observed during P6 ranged between 0.004 mยทs^(-1) and 0.015 mยทs^(-1) , with the w signal exceeding the noise level in all profiles. East of the EPR crest (station 188) profile-averaged VKE levels are generally lower than west of the EPR crest. A section plot of finescale VKE reveals, among other patterns, that the cross-EPR difference is due to a thick layer of elevated finescale VKE over the entire western EPR flank (Figure 1). Average EPR- profiles of finescale VKE, rescaled as dissipation using an empirical scaling (Thurnherr et al., GRL 2015), indicate that the differences are significant (Figure 6). โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”โ€”- (2) Only errors in the CTD package-velocity time series that persist over time scales of minutes can give rise to vertical-velocity errors that are correlated between the two ADCPs. Figure 6: Average height-above-bottom profiles of finescale VKE from the eastern and western of the EPR. VKE is rescaled as dissipation using an empirical scaling (Thurnherr et al., GRL 2015). Error bars indicate 95% confidence from bootstrapping. CCHDO DATA PROCESSING NOTES โ€ข File Merge CCHSIO 320620170703_ct1.zip (download) #342aa Date: 2018-03-05 Current Status: merged โ€ข Update file in As Received to Dataset CCHSIO Date: 2018-03-05 Data Type: CTD Action: Website Update Note: 2017 320620170703 processing - CTD/merge - CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDFLUOR,CTDXMISS,CTDBBP700RAW,CTDRINKO 2018-03-05 CCHSIO Submission filename submitted by date id -------------------- ------------ ---------- ----- 320620170703_ct1.zip Joseph Gum 2017-11-18 13767 Changes ------- 320620170703_ct1.zip - This is a GO-SHIP Cruise: CTDOXY flags are all uncalibrated - added cruise comments - removed DEPTH from header, as all values are -999 - removed space before DATA header - changed SECT_ID description from nbp1706 to P06W - changed parameter name from CTDBACKSCATTER to CTDBBP700RAW (and flag) - renamed files to match CCHDO format - RINKO: only 4 stations have RINKO data: Other stations were submitted as "0.0000,1" Conversion ---------- file converted from software ----------------------- -------------------- ----------------------- 320620170703_nc_ctd.zip 320620170703_ct1.zip hydro 0.8.2-48-g594e1cb Updated Files Manifest ---------------------- file stamp ----------------------- -------------- 320620170703_ct1.zip 20170305CCHSIO 320620170703_nc_ctd.zip 20170305CCHSIO :Updated parameters: CTDPRS,CTDTMP,CTDSAL,CTDOXY,CTDFLUOR,CTDBBP700RAW,CTDXMISS,CTDRINKO opened in JOA with no apparent problems: 320620170703_ct1.zip 320620170703_nc_ctd.zip opened in ODV with no apparent problems: 320620170703_ct1.zip โ€ข File Online Carolina Berys 320620170703_do.txt (download) #4df50 Date: 2017-11-20 Current Status: unprocessed โ€ข File Online Carolina Berys 320620170703_do.pdf (download) #5f9b9 Date: 2017-11-20 Current Status: unprocessed โ€ข File Submission Joseph Gum 320620170703_do.pdf (download) #5f9b9 Date: 2017-11-20 Current Status: unprocessed โ€ข File Submission Joseph Gum 320620170703_do.txt (download) #4df50 Date: 2017-11-20 Current Status: unprocessed โ€ข File Online Carolina Berys 320620170703_ct1.zip (download) #342aa Date: 2017-11-20 Current Status: merged โ€ข File Online Carolina Berys 320620170703_hy1.csv (download) #24c69 Date: 2017-11-20 Current Status: unprocessed โ€ข File Submission Andrew Barna 320620170703_hy1.csv (download) #24c69 Date: 2017-11-20 Current Status: unprocessed Notes These data can go online in the dataset, the cruise report will be submitted as soon the CTD/Bottle residual plots are updated. โ€ข File Submission Joseph Gum 320620170703_ct1.zip (download) #342aa Date: 2017-11-18 Current Status: merged