A. Cruise Report: S04I A.1. Highlights WHP Cruise Summary Information WOCE line designation S04I Expedition designation (ExpoCode) 320696_3 Chief scientists and affiliation Thomas Whitworth III and James H. Swift* Ship RVIB NATHANIEL B. PALMER Cruise dates 1996.MAY.03 - 1996.JUL.04 Ports of call Cape Town, S. Africa - Hobart, Australia Number of stations 108 full-depth CTD stations 58° 0.23' S Geographic boundaries 20° 0.34' E 120° 0.08' E 65° 41.97' S Floats and drifters deployed 17 ALACE floats Moorings deployed or recovered 9 self-reporting current meter moorings *Thomas Whitworth III James H. Swift Department of Oceanography Scripps Institution of Oceanography Texas A&M University University of California, San Diego College Station, TX, 77843 La Jolla, CA, 92093 twhitworth@tamu.edu jswift@ucsd.edu Authors S. Rutz, D. Chipman, M. Mensch, F. Delahoyd, D. Breger, R. Key, E. Peltola, T. Whitworth WOCE Hydrographic Program Line S04I was conducted on the RVIB NATHANIEL B. PALMER on voyage S229 from 3 May to 4 July, 1996. The voyage began in Cape Town, Republic of South Africa, and ended in Hobart, Australia. Co-Chief Scientists for the cruise were Thomas Whitworth III/TAMU and James H. Swift/SIO. WHP leg S04I was a cooperative effort among the PIs listed in Table 1. The members of the scientific party are listed in Table 2. Table 1. Principal Investigators for WOCE S04I Component Principal Investigator Institution ----------------- ---------------------- ----------- CTD/Hydrography J. Swift SIO CFCs W. Smethie/M. Warner LDEO/UW Tritium, 3He, 18O P. Schlosser LDEO CO2 T. Takahashi LDEO Alkalinity F. Millero Miami 14C R. Key Princeton current meters W. Nowlin/T. Whitworth TAMU Transmissometer W. Gardner TAMU LADCP* E. Firing/P. Hacker UH ALACE floats R. Davis SIO * The LADCP was lost during a test, therefore no LADCP data are reported for this cruise. Table 2. Participants on WOCE S04I Participant Affiliation Responsibility ---------------- ----------- ----------------------------------------------- Isabelle Ansorge UCT CTD console, sampling, salinities Dee Breger LDEO Tritium, 3He, 18O Christie Campbell ASA deck ops, sampling, hazardous waste, salinities Kent Chen ASA sampling, oxygen, NBP computer David Chipman LDEO CO2 Scott Colburn ASA PDR, sampling, NBP ET Craig Hallman ODF deck ops, sampling, oxygen Steve Covey UW CFCs Frank Delahoyde ODF ODF systems, data q.c. Bob Key PU 14C, gadfly Leonard Lopez ODF deck ops, oxygen Guy Mathieu LDEO CFCs Carl Mattson ODF TIC, deck supv., ET Rod McCabe ASA sampling, NBP computer Manfred Mensch LDEO CFCs Stacey Morgan ODF nutrients Jim Noyes SIO CTD console, sampling Alex Orsi UW CTD console, sampling, analysis Ron Patrick ODF deck supv., bottle q.c. Esa Peltola UM Alkalinity Erik Quiroz TAMU nutrients Blaine Reynolds ASA PDR, rosette prep., NBP ET Stephany Rubin LDEO CO2 Steve Rutz TAMU watch leader., CTD console, sampling, ADCP Buzz Scott ASA deck ops., salinities, MT Colm Sweeney LDEO CO2 Jim Swift SIO watch leader., CTD console, sampling, analysis Mark Talkovic ASA deck ops., salinities, MT Tom Whitworth TAMU indirection, analysis Kevin Wood ASA deck ops., sampling, MPC ASA: Antarctic Support Associates UM: University of Miami (RSMAS) 61 Inverness Dr. East, Suite 300 4600 Rickenbacker Cswy. Englewood, CO 80112 Miami, FL 33149 SIO: Scripps Instit. of Oceanog. LDEO: Lamont-Doherty Earth Observatory Univ. of Calif.-San Diego Columbia University La Jolla, CA Palisades, NY 10964 TAMU: Texas A&M University UW: University of Washington Dept. of Oceanography School of Oceanography College Sta. TX 77843 Seattle, WA 98195 ODF: Ocean Data Facility UCT: University of Cape Town Scripps Instit. of Oceanog. Department of Oceanography 9500 Gilman Dr. Rondebosch, Cape Town La Jolla, CA 92093 South Africa PU: Princeton University Dept. of Geosciences 207 Guyot Hall Princeton, N.J. 08544 A2. Scientific Program Summary Narrative The cruise constituted the Indian Ocean portion of WOCE line S04, a meridional circumnavigation of Antarctica at a nominal latitude of 60°S. This segment covered the longitudes 20°E to 120°E. After departure from Cape Town, a bottom-tracking course was set to provide about 8 hours of depths along the 200-m isobath to calculate the offset between the ship's gyro and the underway Acoustic Doppler Current Profiler (ADCP). Upon reaching deep water, the CTD wire was lowered to 5500 m wire out to tension the wire on the winch, and subsequently, two test CTD casts were made to choreograph the procedures for launching and recovering the package in the unfamiliar setting of the Palmer's Baltic Room. At 0330 on 7 May, the Palmer turned back toward South Africa to seek medical attention for a crew member. The ship was diverted to the naval base at Simonstown where fuel was available, and the morning and afternoon of May 10 were spent getting the crewman treated and refueling. Bottom-tracking for the ADCP calibration was repeated into and out of Simonstown. On Sunday, 12 May, a third CTD test cast was being recovered when a sudden wave lifted the rosette out of the water and then dropped it. The wire parted at the sheave, and the entire package was lost. The only piece of equipment without back-up was the lowered ADCP unit belonging to the University of Hawaii. Subsequent days were spent preparing a second rosette unit, considering alternative launch and recovery procedures and defining guidelines for the sea state in which CTD operations could be conducted on the Palmer. Because the Palmer reacted differently from UNOLS vessels we were accustomed to, the planned cruise track was modified to lie in, or closer to the ice where swell would be less of a problem. Station 1 was occupied at 58°S, 20°E and the first station line was run southeast to Gunnerus Ridge, about 50 miles south of the ice edge. Station positions for the cruise are shown in Fig. 1. During the transit to station 1 and continuing to 58°S, 17 ALACE floats were launched. Details are provided in Table 3. Stations across the Enderby Abyssal Plain trended east-northeast from 66°S at 33°E, to 61°S at 83°E on the Kerguelen Plateau. A line of stations (35-42) was made north from the 500-m isobath on the continental slope at 53°E, and three self-reporting current meters were deployed along the slope. Details of the current meter deployments are given in Table 4. A line of stations (65- 72) extending east from the crest of the Kerguelen Plateau was made at about 59° S, and three more current meters were placed in the boundary current on the eastern flank of the Plateau. On June 8, after station 72, science operations were suspended for seven days when the Palmer was diverted to Mirnyi Station in the Davis Sea to deliver emergency food supplies. On June 14, the Palmer left Mirnyi and began a line of stations (73-86) from the shelf break of the Davis Sea to Kerguelen Plateau. One current meter was placed near the 3000-m isobath north of the Antarctic Continental Slope, and two were deployed at the southern end of Kerguelen Plateau. The zonal line of stations at a nominal latitude of 62°S was resumed at 90°E. Ice conditions, fuel and time considerations necessitated 45-mile station separation for most of the final 22 stations, which terminated with station 108 at 120°E. Summary Information 108 full-depth CTD stations were made exclusive of test stations at the beginning of the cruise and a dedicated CFC archive-sample cast at the end of the cruise. Nine self-reporting current meters and 17 ALACE floats were deployed Table 3. ALACE deployments on WOCE S04I Ser# Type Lat Long Time/Date Ser# Type Lat Long Time/Date ---- ---- -------- -------- --------- ---- ---- -------- -------- ---------- 628 T 37-58.3S 20-16.1E 2056Z 5/4 641 Std 47-59.4S 19-12.0E 2221Z 5/13 346 Std 38-59.1S 21-46.4E 0610Z 5/5 642 Std 49-32.6S 19-16.5E 0700Z 5/14 629 T 39-59.1S 21-46.1E 1546Z 5/5 643 Std 50-59.8S 19-20.7E 1458Z 5/14 559 Std 40-59.4S 21-42.2E 2118Z 5/5 607 CTD 51-58.7S 19-23.8E 2045Z 5/14 634 Std 41-58.8S 21-38.5E 0228Z 5/6 644 Std 52-59.8S 19-26.4E 0224Z 5/15 566 Std 43-29.9S 21-32.9E 1040Z 5/6 608 CTD 54-30.0S 19-31.7E 1035Z 5/15 604 CTD 44-59.9S 21-27.3E 2042Z 5/6 645 Std 55-59.4S 19-47.2E 1855Z 5/15 640 Std 45-59.9S 19-06.5E 1118Z 5/13 609 CTD 57-30.0S 19-58.6E 0331Z 5/16 605 CTD 47-00.0S 19-09.7E 1651Z 5/13 *T = temperature, Std = Standard, CTD = cond/temp/depth Table 4. Self-reporting current meter deployments CMfl serial# time date latitude longitude depth MAB* --- ------- ----- --------- --------- --------- ------ --- A 26935 0732Z 28 May 96 65-22.8 S 53-14.2 E 1740 m 50 B 26939 1125Z 28 May 96 65-14.0 S 53-06.5 E 1900 m 50 C 26936 1904Z 28 May 96 65-07.0 S 52-59.6 E 2260 m 100 D 26937 1706Z 6 June 96 59-42.9 S 84049.9 E 2020 m 50 E 26941 2209Z 6 June 96 59-40.6 S 85-07.9 E 3080 m 50 F 26943 2231Z 6 June 96 59-40.3 S 85-10.9 E 4225 m 50 G 26944 1331Z 16 June 96 64-03.8 S 92-21.5 E 3275 m 100 H 26938 0614Z 19 June 96 63-00.0 S 85-00.0 E 3058 m 50 I 26940 1212Z 19 June 96 62-59.6 S 84-31.5 E 2740 m 50 fl letters correspond to Fig. 1 * MAB = meters above bottom World Ocean Circulation Experiment Southern Indian Ocean S4I R/V Nathaniel B. Palmer NBP96-3 3 May - 4 July 1996 Cape Town, South Africa - Hobart, Tasmania, Australia Expocode: 320696_3 Co-Chief Scientists: Dr. Thomas Whitworth (Texas A&M University) Dr. James H. Swift (Scripps Institution of Oceanography) S4I Cruise Track Oceanographic Data Facility (ODF) Final Cruise Report 1 August 2003 Data Submitted by: Oceanographic Data Facility Scripps Institution of Oceanography La Jolla, CA 92093-0214 http://odf.ucsd.edu DESCRIPTION OF MEASUREMENT TECHNIQUES AND CALIBRATIONS 1. Basic Hydrography Program The basic hydrography program consisted of salinity, dissolved oxygen and nutrient (nitrite, nitrate, phosphate and silicate) measurements made from bottles taken on CTD/rosette casts, plus pressure, temperature, salinity and dissolved oxygen from CTD profiles. 109 CTD/rosette casts were made at 108 stations, usually to within 5-15 meters of the bottom. Station 2 cast 1 was aborted at the surface because of signal failure at 322m on the down- cast; it is not otherwise mentioned in this release or documentation. Water was found inside the CTD case; after repairs, station 2 cast 2 was successfully accomplished. 17 ALACE floats were deployed during the transit from Cape Town to station 1. 9 expendable current meters were deployed following 8 stations along the cruise. The R/V Nathaniel B. Palmer departed from Cape Town, South Africa on May 3, 1996. One test cast was accomplished on May 6; on May 7, the ship turned back toward South Africa to seek medical attention for a crew member. The ship docked at the naval base at Simonstown on May 10, departing later the same day to resume the expedition. 2 more test casts were done during the transit. During the recovery of the second of these casts, a rogue wave lifted the rosette out of the water and then dropped it. The wire parted at the sheave, and the rosette package was lost. A backup rosette was prepared and used for the remainder of the cruise. 108 CTD/Rosette stations were occupied between May 16 and June 27 along the nominal S4I line (60 deg.S), between 58-66 deg.S latitude and 20-120 deg.E longitude. An additional line (stations 35-42) was made northward from the 500m isobath on the continental slope at 53 deg.E back to the main track. There was a 6.5-day (June 8-14) diversion from the track after station 72 to deliver emergency food supplies to Mirnyy Station in the Davis Sea. After Mirnyy, an extra line (stations 73-86) was run northward, then westward, from the shelf break of the Davis Sea back toward the S4I line. The cruise ended in Hobart, Tasmania, Australia on July 4, 1996. 3655 bottles were tripped resulting in 3651 usable bottles. Any problems encountered during data acquisition or processing are described later in this document. The resulting data set met and in many cases exceeded WHP specifications. The distribution of samples is illustrated in Figures 1.0, 1.1 and 1.2. Figure 1.0 S4I sample distribution, stas 1-34. Figure 1.1 S4I sample distribution, stas 35-72. Figure 1.2 S4I sample distribution, stas 73-108. 2. Water Sampling Package Hydrographic casts were performed with a rosette system consisting of a 36-bottle rosette frame (ODF), a General Oceanics (GO) 36-place pylon (Model 2216) and 36 10-liter PVC bottles (ODF). Underwater electronic components consisted of an ODF-modified NBIS Mark III CTD (ODF #3) and associated sensors, SeaTech transmissometer (TAMU) and Benthos pinger (Model 2216). The CTD was mounted horizontally along the bottom of the rosette frame, with the transmissometer, a SensorMedics dissolved oxygen sensor and an FSI secondary PRT sensor deployed next to the CTD. The pinger was monitored during a cast with a precision depth recorder (PDR) in the ship's laboratory. The rosette system was suspended from a three- conductor 0.322" electro-mechanical cable. Power to the CTD and pylon was provided through the sea cable from the ship. Separate conductors were used for the CTD and pylon signals. The transmissometer, dissolved oxygen and secondary temperature were interfaced with the CTD, and their data were incorporated into the CTD data stream. Deep Sea Reversing Thermometers (DSRTs) were used occasionally on this leg to monitor for CTD pressure or temperature drift. Three rosette test casts were performed prior to station 1: 998 (6 May), 997 (11 May) and 996 (12 May). During retrieval on the third test cast (996), a wave caught the rosette, and the wire jumped the sheave and broke. The rosette, bottles and all associated electronics were lost. The only instruments that did not have backup units were the UH LADCP and an ODF altimeter. A spare altimeter was used during stations 1-5 and 8-10, but was removed for the rest of the cruise; it never worked properly and was identified as the source of the degraded signal seen during the up-cast for station 5. The deck watch prepared the rosette approximately 45 minutes prior to each cast. All valves, vents and lanyards were checked for proper orientation. The bottles were cocked and all hardware and connections rechecked. Time, position and bottom depth were logged by the console operator at arrival on station. The rosette system was deployed from the Palmer's main deck out of the starboard-side Baltic Room, a protected rosette room and winch shed with an external door and an extension boom. The deployment door to the Baltic Room was opened after the ship had finished positioning, which sometimes entailed clearing a hole in the ice. Deployment was assisted by tag lines threaded through rings on the rosette for stabilization. Each rosette cast was lowered to within 5-15 meters of the bottom, unless the bottom return from the pinger was extremely poor. As noted already, no altimeter data were available to assist with bottom approaches after station 5. Bottles on the rosette were each identified with a unique serial number. Usually these numbers corresponded to the pylon tripping sequence, 1-36, where the first (deepest) bottle tripped was bottle #1. Bottle #8 had repeated drain valve leakage problems and was replaced with bottle #37 (stations 13-25 and 35-47), Ocean Instrument Tech. (OIT) test bottle #61 (stations 26-34) and Antarctic Support Associates (ASA) test bottle #63 (stations 48-108). Bottle #4 was missing (apparently imploded) after station 77, and was replaced with bottle #39 for stations 78-108. GO test bottle #62 replaced bottles #10 (stations 26-28) and #6 (stations 82-83). Averages of CTD data corresponding to the time of bottle closure were associated with the bottle data during a cast. Pressure, depth, temperature, salinity and density were immediately available to facilitate examination and quality control of the bottle data as the sampling and laboratory analyses progressed. Recovering the package at the end of deployment was essentially the reverse of the launching with the additional use of air-tuggers for added stabilization. The rosette was placed onto the Baltic Room deck, then the deployment door was closed prior to sampling. The bottles and rosette were examined before samples were taken, and any unusual situations or circumstances were noted on the sample log for the cast. Seawater froze on rosette bottles several times during recovery, but quickly thawed in the Baltic Room. There was never any evidence of water freezing in the bottles or spigots. Routine CTD maintenance included soaking the conductivity and CTD O2 sensors in distilled water between casts to maintain sensor stability. Beginning at station 20, the distilled water was replaced by salt water ~1 hour prior to deployment to reduce the possibility of sensors freezing before entering the water. This preventive measure was not totally successful, and freezing did occur during deployment on some casts. When freezing was detected by the console operator, the rosette was lowered to 30-80 meters to thaw the sensors, then raised back to the surface. Rosette maintenance was performed on a regular basis. O-rings were changed as necessary and bottle maintenance was performed each day to insure proper closure and sealing. Valves were inspected for leaks and repaired or replaced as needed. The transmissometer windows were cleaned prior to deployment approximately every 20 casts. The air readings were noted in the TAMU transmissometer log book after each cleaning. Transmissometer data were monitored for potential problems during every cast, but were not processed by ODF beyond initial block averaging. The starboard-side Baltic Room Markey winch was used throughout the cruise. Only one sea cable retermination was necessary, prior to station 57. 3. Underwater Electronics Packages CTD data were collected with a modified NBIS Mark III CTD (ODF #3). This instrument provided pressure, temperature, conductivity and dissolved O2 channels, and additionally measured a second temperature with an FSI oceantemperature module (OTM) as a calibration check. An FSI ocean pressure module (OPM) was substituted in place of the secondary temperature OTM for four casts. Other data channels included elapsed-time, several power supply voltages and transmissometer. The instrument supplied a 15-byte NBIS-format data stream at a data rate of 25 Hz. Modifications to the instrument included revised pressure and dissolved O2 sensor mountings; ODF-designed sensor interfaces for O2, FSI-OTM PRT and transmissometer; implementation of 8-bit and 16-bit multiplexer channels; an elapsed-time channel; instrument ID in the polarity byte and power supply voltages channels. Table 3.0 summarizes the serial numbers of instruments and sensors used during S4I. Table 3.0 S4I Instrument/Sensor Serial Numbers | ODF | SensorMedics | SeaTech Station(s) | CTD+ | Model 147737 | Transmissometer | ID# | Oxygen Sensor | (TAMU) -----------|------|-----------------|---------------- 1-31,39-61 | 3a | | -----------|------| | 32-38 | 3b | | -----------|------| | 62-100 | 3c | | -----------|------| 5-02-22 | 151D 101-102 | 3d | | -----------|------| | 103-106 | 3e | | -----------|------| | 107-108 | 3f | | -----------|------|-----------------|---------------- + See table below for ODF CTD serial numbers ODF CTD #3 sensor serial numbers: NBIS | Pressure | Temperature | Conductivity MKIIIB | Paine Model | PRT1 | PRT2/(PRS2) | CTD | 211-35-440-05 | Rosemount | FSI | NBIS Model (ODF-ID#) | strain gage/0-8850psi | Model 171BJ | OTM/(OPM) | 09035-00151 ----------|-----------------------|-------------|-------------|------------- 3a | | | | E55 ----------| | | OTM/1320T |------------- 3b | | | | P42 ----------| | |-------------|------------- 3c | | | OTM/1322T | ----------| 77011 | 14373 |-------------| 3d | | | OTM/1321T | ----------| | |-------------| O17 3e | | | (OPM/1326P) | ----------| | |-------------| 3f | | | OTM/1320T | The CTD pressure sensor mounting had been modified to reduce the dynamic thermal effects on pressure. The sensor was attached to a section of coiled, oil-filled stainless-steel tubing that was connected to the end-cap pressure port. The transducer was also insulated. The NBIS temperature compensation circuit on the pressure interface was disabled; all thermal response characteristics were modeled and corrected in software. The O2 sensor was deployed in a pressure-compensated holder assembly mounted separately on the rosette frame and connected to the CTD by an underwater cable. The O2 sensor interface was designed and built by ODF using an off-the-shelf 12-bit A/D converter. The transmissometer interface was a similar design. Although the secondary temperature sensor was located within 6 inches of the CTD conductivity sensor, it was not sufficiently close to calculate coherent salinities. It was used as a secondary temperature calibration reference rather than as a redundant sensor, with the intent of eliminating the need for mercury or electronic DSRTs as calibration checks. Three secondary temperature sensors were interchanged during S4I. The General Oceanics (GO) 1016 36-place pylon was used in conjunction with an ODF-built deck unit and external power supply instead of a GO pylon deck unit. This combination provided generally reliable operation and positive confirmation. The pylon emitted a confirmation message containing its current notion of bottle trip position, which could be useful in sorting out mis-trips. The acquisition software averaged CTD data corresponding to the rosette trip as soon as the trip was initiated until the trip confirmed, typically 3.5 +/- 1 seconds on S4I. There were 13 random bad trip confirmations during S4I; 12 of these were noticed in a timely manner by the console operator and re-tripped successfully. 3 odd trip confirmations resulted in open bottles at the surface. There were 255 other odd trip confirmations, most of which were duplicates of valid confirmations or in place of normal confirmations. 2 casts (stas 78 and 79) were re-started mid-up-cast because of pylon communication or confirmation problems. 2 casts (stas 40 and 79) had trip confirmations that were off by 1 level on many or all bottles. 2 other casts (stas 52 and 56) confirmed normally but returned to the surface with the first two bottles tripped at unknown depths, and the rest 2 trip levels deeper than expected. The bottles for these casts were matched up to the correct CTD trip depths after the casts, by comparison of CTD and bottle data water properties. Bad or odd confirmations that affected bottle trips are documented in Appendix D. 4. Navigation and Bathymetry Data Acquisition Navigation data were acquired from the ship's Ashtech GPS receiver via the network, which reported full P-code position information. Data were logged automatically at one-minute intervals by one of the Sun SPARCstations. Underway bathymetry was logged manually from the 12 kHz Raytheon/EPC PDR at five-minute intervals (or when possible in the ice), then corrected according to Carter [Cart80] and merged with the navigation data to provide a time-series of underway position, course, speed and bathymetry data. These data were used for all station positions, PDR depths and bathymetry on vertical sections. 5. CTD Data Acquisition, Processing and Control System The CTD data acquisition, processing and control system consisted of a Sun SPARCstation LX computer workstation, ODF-built CTD and pylon deck units, CTD and pylon power supplies, and a VCR recorder for real-time analog backup recording of the sea cable signal. The Sun system consisted of a color display with trackball and keyboard (the CTD console), 18 RS-232 ports, 2.5 GB disk and 8mm cartridge tape. Two other Sun SPARCstation LX systems were networked to the data acquisition system, as well as to the rest of the networked computers aboard the Palmer. These systems were available for real-time CTD data display and provided for hydrographic data management and backup. Two HP 1200C color inkjet printers provided hardcopy capability from any of the workstations. The CTD FSK signal was demodulated and converted to a 9600 baud RS-232C binary data stream by the CTD deck unit. This data stream was fed to the Sun SPARCstation. The pylon deck unit was connected to the Sun LX through a bi-directional 300 baud serial line, allowing bottle trips to be initiated and confirmed by the data acquisition software. A bitmapped color display provided interactive graphical display and control of the CTD rosette sampling system, including real-time raw and processed CTD data, navigation, winch and rosette trip displays. The CTD data acquisition, processing and control system was prepared by the console watch a few minutes before each deployment. A console operations log was maintained for each deployment, containing a record of every attempt to trip a bottle as well as any pertinent comments. Most CTD console control functions, including starting the data acquisition, were initiated by pointing and clicking a trackball cursor on the display at icons representing functions to perform. The system then presented the operator with short dialog prompts with automatically generated choices that could either be accepted as defaults or overridden. The operator was instructed to turn on the CTD and pylon power supplies, then to examine a real-time CTD data display on the screen for stable voltages from theunderwater unit. Once this was accomplished, the data acquisition and processing were begun and a time and position were automatically logged for the beginning of the cast. A backup analog recording of the CTD signal on a VCR tape was started at the same time as the data acquisition. A rosette trip display and pylon control window popped up, giving visual confirmation that the pylon was initializing properly. Various plots and displays were initiated. When all was ready, the console operator informed the deck watch by radio. Once the deck watch had deployed the rosette, it was immediately lowered without pausing at the sea surface. The deck watch informed the console operator that the rosette was on its way down (also confirmed by the computer displays). If the console operator noticed that sensors were frozen on entry, the package was stopped at 30-80 meters, then raised to just below the surface to allow the sensors to thaw. The console operator or deck watch leader then provided the winch operator with a target depth (wire-out) and maximum lowering rate, normally 60-70 meters/minute for this package. The package built up to the maximum rate during the first few hundred meters, then optimally continued at a steady rate without any stops during the down-cast. The console operator examined the processed CTD data during descent via interactive plot windows on the display, which could also be run at other workstations on the network. Additionally, the operator decided where to trip bottles on the up-cast, noting this on the console log. The PDR was monitored to insure the bottom depth was known at all times. The deck watch leader assisted the console operator by monitoring the rosette's distance to the bottom using the difference between the rosette's pinger signal and its bottom reflection displayed on the PDR. No altimeter was available to assist with bottom approaches. The winch speed was usually slowed to ~30 meters/minute during the final approach. The winch and PDR displays allowed the watch leader to refine the target depth relayed to the winch operator and safely approach to within 5-15 meters of the bottom. Bottles were closed on the up-cast by pointing the console trackball cursor at a graphic firing control and clicking a button. The data acquisition system responded with the CTD rosette trip data and a pylon confirmation message in a window. A bad or suspicious confirmation signal typically resulted in the console operator repositioning the pylon trip arm via software, then re-tripping the bottle, until a good confirmation was received. All tripping attempts were noted on the console log. The console operator then instructed the winch operator to bring the rosette up to the next bottle depth. The console operator was also responsible for generating the sample log for the cast. After the last bottle was tripped, the console operator directed the deck watch to bring the rosette on deck. It was sometimes necessary to close the surface bottles "on the fly" due to a risk of slack wire at higher sea states. Once the rosette was on deck, the console operator terminated the data acquisition and turned off the CTD, pylon and VCR recording. The VCR tape was filed. Usually the console operator also brought the sample log to the rosette room and served as the sample cop. 6. CTD Data Processing ODF CTD processing software consists of over 30 programs running under the Unix operating system. The initial CTD processing program (ctdba) is used either in real-time or with existing raw data sets to: o Convert raw CTD scans into scaled engineering units, and assign the data to logical channels o Filter various channels according to specified filtering criteria o Apply sensor- or instrument-specific response-correction models o Provide periodic averages of the channels corresponding to the output time-series interval o Store the output time-series in a CTD-independent format Once the CTD data are reduced to a standard-format time-series, they can be manipulated in various ways. Channels can be additionally filtered. The time-series can be split up into shorter time-series or pasted together to form longer time-series. A time-series can be transformed into a pressure- series, or into a larger-interval time-series. The pressure calibration corrections are applied during reduction of the data to time-series. Temperature, conductivity and oxygen corrections to the series are maintained in separate files and are applied whenever the data are accessed. ODF data acquisition software acquired and processed the CTD data in real- time, providing calibrated, processed data for interactive plotting and reporting during a cast. The 25 Hz data from the CTD were filtered, response-corrected and averaged to a 2 Hz (0.5-second) time-series. Sensor correction and calibration models were applied to pressure, temperature, conductivity and O2. Rosette trip data were extracted from this time- series in response to trip initiation and confirmation signals. The calibrated 2 Hz time-series data, as well as the 25 Hz raw data, were stored on disk and were available in real-time for reporting and graphical display. At the end of the cast, various consistency and calibration checks were performed, and a 2-db pressure-series of the down-cast was generated and subsequently used for reports and plots. CTD plots generated automatically at the completion of deployment were checked daily for potential problems. The two PRT temperature sensors were inter-calibrated and checked for sensor drift. The CTD conductivity sensor was monitored by comparing CTD values to check-sample conductivities, and by deep theta-salinity comparisons between down- and up-casts as well as adjacent stations. The CTD O2 sensor was calibrated to check-sample data. Two casts (stations 30 and 31) exhibited an unacceptable level of primary PRT temperature noise which was traced to a water leak in the sensor turret. The secondary PRT temperature was used in these cases. CTD salinity for these casts is noisier than usual because of the greater distance of the secondary PRT from the conductivity sensor, and because of potential noise induced on the conductivity sensor by the flooded turret. There was a high level of conductivity drift during stations 32-38, which used a new and apparently defective conductivity sensor, and during stations 55-61, just before the original conductivity sensor was replaced with yet another new sensor. Since down- and up-cast conductivities were very different for these casts, it was necessary to use the up-casts for these stations, where bottle-CTD differences could be used to determine pressure-dependent conductivity corrections for each cast individually. A few casts exhibited conductivity offsets due to biological or particulate artifacts. Some casts were subject to noise in the data stream caused by sea cable or slip-ring problems, or by moisture in the interconnect cables between the CTD and external sensors (i.e. O2). Intermittent noisy data were filtered out of the 2 Hz data using a spike-removal filter. A least- squares polynomial of specified order was fit to fixed-length segments of data. Points exceeding a specified multiple of the residual standard deviation were replaced by the polynomial value. Density inversions can be induced in high-gradient regions by ship- generated vertical motion of the rosette. Detailed examination of the raw data shows significant mixing occurring in these areas because of "ship roll". In order to minimize density inversions, a ship-roll filter was applied to all casts during pressure-sequencing to disallow pressure reversals. The first few seconds of in-water data were excluded from the pressure-series data, since the sensors were still adjusting to the going- in-water transition. Pressure intervals with no time-series data can optionally be filled by double-quadratic interpolation/extrapolation. Most pressure intervals missing/filled during this leg were within the top 0-4 db, caused by chopping off going-in-water transition data during pressure-sequencing. However, there were a number of casts where temperature or conductivity sensors froze in transit from the deck into the water. Ideally, these were noticed by the console operator, and the casts were returned to near- surface water and restarted after thawing. However, a number of casts with freezing problems were not noticed. At the request of one of the co-chief scientists, down-cast data were extrapolated from the "thaw" point back to the surface whenever there was a clear, stable mixed layer. The resulting data were compared to original down-cast data from the un-frozen sensor, up-cast data from the same cast and density profiles. When the down-cast CTD data have excessive noise, gaps or offsets, the up- cast data are used instead. This also applied to frozen-sensor casts where down-casts could not be extrapolated without distortion, or where sensors remained frozen below the mixed layer. CTD data from down- and up-casts are not mixed together in the pressure-series data because they do not represent identical water columns (due to ship movement, wire angles, etc.). The up-casts used for final S4I CTD data are indicated in Appendix C. There is an inherent problem in the internal digitizing circuitry of the NBIS Mark III CTD when the sign bit for temperature flips. Raw temperature can shift 1-2 millidegrees as values cross between positive and negative, a problem usually avoided by offsetting the raw PRT readings by ~1.5 deg.C. The conductivity channel also can shift by 0.001-0.002 mS/cm as raw data values change between 32768/32767, where all the bits flip at once. This is typically not a problem in shallow to intermediate depths because such a small shift becomes negligible in higher gradient areas. There were a number of casts colder than -1.5 deg.C, where raw temperature values crossed the 0 deg.C threshold. All transitions falling in lower- gradient areas were shallower than 480 db and showed no density inversions. All raw conductivity values were lower than 32768 and unaffected by this problem. Appendix C contains a table of CTD casts requiring special attention. S4I CTD-related comments, problems and solutions are documented in detail. 7. CTD Laboratory Calibration Procedures Pre-cruise laboratory calibrations of CTD pressure and temperature sensors were used to generate tables of corrections applied by the CTD data acquisition and processing software at sea. These laboratory calibrations were also performed post-cruise. Pressure and temperature calibrations were performed on CTD #3 at the ODF Calibration Facility in La Jolla. Pre-cruise calibrations were done in March 1996, and post-cruise calibrations were done in July 1996. The CTD pressure transducer was calibrated in a temperature-controlled water bath to a Ruska Model 2400 Piston Gage pressure reference. Calibration data were measured pre-/post-cruise at -1.89/-1.10 deg.C to a maximum loading pressure of 6080 db, and 10.08/30.34 deg.C to 1190 db. An additional pressure calibration was done post-cruise at 4.07 deg.C to 6080 db. Figures 7.0 and 7.1 summarize the CTD #3 laboratory pressure calibrations performed in March and July 1996. Figure 7.0 Pressure calibration for ODF CTD #3, March 1996. Figure 7.1 Pressure calibration for ODF CTD #3, July 1996. Additionally, dynamic thermal-response step tests were conducted on the pressure transducer to calibrate dynamic thermal effects. These results were combined with the static temperature calibrations to optimally correct the CTD pressure. CTD PRT temperatures were calibrated to an NBIS ATB-1250 resistance bridge and Rosemount standard PRT in a temperature-controlled bath. The primary and secondary CTD temperatures were offset by ~1.5 and ~2 deg.C to avoid the 0-point discontinuity inherent in the internal digitizing circuitry. Standard and CTD temperatures were measured pre-cruise for the primary PRT at 7 different bath temperatures between -1.9 and 10.1 deg.C. The primary and secondary PRT #FSI-1320T were both calibrated post-cruise at more than a dozen bath temperatures between -1.9 and 30.3 deg.C. Figures 7.2 and 7.3 summarize the laboratory calibrations performed on the CTD #3 primary PRT during March and July 1996. Figure 7.4 shows the laboratory calibration performed on the CTD #3 secondary PRT (FSI-1320T only) during July 1996. Figure 7.2 Primary PRT Temperature Calibration for ODF CTD #3, March 1996. Figure 7.3 Primary PRT Temperature Calibration for ODF CTD #3, July 1996. Figure 7.4 Secondary PRT (FSI-1320T) Temperature Calibration for ODF CTD #3, July 1996. These laboratory temperature calibrations were referenced to an ITS-90 standard. Temperatures were converted to the IPTS-68 standard during processing in order to calculate other parameters, including salinity and density, which are currently defined in terms of that standard only. Final calibrated CTD temperatures are reported using the ITS-90 standard. 8. CTD Calibration Procedures ODF CTD #3 had recently been acquired by ODF and did not have an extensive calibration history. A redundant PRT sensor was used as a temperature calibration check while at sea. CTD conductivity and dissolved O2 were calibrated to in situ check samples collected during each rosette cast. Final pressure, temperature, conductivity and oxygen corrections were determined during post-cruise processing. 8.1. CTD #3 Pressure There was a pre- to post-cruise shift in the loading curves (increasing pressure) of less than -0.5 db in the top 2000 db, gradually shifting to a maximum +0.5 db at the maximum pressure in the cold-bath laboratory calibrations for pressure. The unloading curves were similar in the top 1000 db, and shifted a fairly consistent +0.5 db in the post-cruise. The intermediate-temperature (10/4 deg.C pre-/post-cruise) pressure calibrations were less easily compared, since they differed by 6 deg.C and were done to different maximum pressures. For easier comparison, the deep extrapolation of the pre-cruise 10 deg.C calibration was used. The loading curves were within +/-0.5 db of each other in the top 3500 db, with the post-cruise shifting by a maximum -0.5 db at 6080 db. The unloading curves crossed around 4500 db, with the post-cruise calibration showing a maximum +0.8 db at 1100 db, then closing in again to within +/-0.2 db near the surface. The 4 deg.C calibration (post-cruise) would typically be twice as close as the 10 deg.C calibration (pre-cruise) to the -1 deg.C calibrations, if there were no shift in CTD pressure. However, the difference between the cold and intermediate calibrations at maximum pressure became twice as large instead (0.6 db in 12 deg.C pre-cruise vs 1.3 db in 5 deg.C post- cruise). The differences between the calibrations were still less than 1 db at any calibration temperature or pressure, a relatively insignificant amount. A test comparing the results of using one calibration or the other showed less than +/-0.3 db differences in maximum pressures for each cast deeper than 1500 db, and 0.3 to 0.9 db differences in casts shallower than 1500 db. The pre-cruise calibration data, plus the dynamic thermal- response correction, were applied to S4I CTD #3 pressure data to generate final pressures. Down-cast surface pressures were automatically adjusted to 0 db as the CTD entered the water; any difference between this value and the calibration value was automatically adjusted during the top 50 decibars. Residual pressure offsets at the end of each up-cast (the difference between the last corrected pressure in-water and 0 db) averaged 0.9 db, indicating no significant problems with the final pressure corrections. The entire pre- to post-cruise laboratory calibration shift for the pressure sensor on CTD #3 was less than one-half the magnitude of the WOCE accuracy specification of 3 db. Final adjusted S4I CTD pressures should be well within the desired standards. An FSI-OPM/pressure module (1326P) was substituted for the secondary PRT during stations 103 through 106 as a test of the OPM. These secondary pressure data were neither processed nor calibrated. 8.2. CTD #3 Temperature Three different FSI-OTM/PRT sensors (S/N 1320T, 1322T, 1321T) were deployed as a second temperature channel (PRT2) and compared with the primary PRTchannel (PRT1) on all casts except stations 103-106 to monitor for drift. The response times of the primary and secondary PRT sensors were matched, then preliminary corrected temperatures were compared for a series of standard depths from each CTD down-cast. OTM-1320T was used for stations 1-61 and 107-108, OTM-1322T was used for stations 62-100, and OTM-1321T was used for stations 101-102 only. Since no OTM was attached during the pre-cruise calibration, a simple offset of -2.0 was used to correct PRT2 for comparison to PRT1 data, a correction within 0.0025 deg.C of calibration checks of all 3 OTMs in November 1996. The differences between the CTD #3 primary PRT and all 3 OTM sensors remained a fairly stable +/-0.0005 deg.C for pressures deeper than 1500 db. A stable conductivity correction also indicated no shift in the primary PRT. Figure 8.2.0 summarizes the comparison between the primary and secondary PRT temperatures. Figure 8.2.0 S4I comparison of CTD #3 primary vs. secondary PRT temperatures, pressure > 1500 db (no Sta.031). The primary temperature sensor laboratory calibrations indicated a -0.0015 deg.C shift at -1.5 to 6 deg.C, with no slope change, from pre- to post- cruise. Figure 8.2.1 shows the pre-/post-cruise PRT1 calibrations plotted together, using only uncorrected PRT1 values above 0 deg.C. Figure 8.2.1 WOCE96-S4I Primary temperature (PRT1) correction for ODF CTD #3, March + July'96 calibs, rawPRT1 > 0 deg.C only. The post-cruise PRT1 calibration measured more temperature points and was more consistent, so it was offset by +0.00075 deg.C (half of the pre- to post-cruise change) and applied to S4I temperature data. Figure 8.2.2 shows the offset post-cruise temperature calibration used to correct CTD #3 PRT1 data. Figure 8.2.2 WOCE96-S4I Primary temperature (PRT1) correction for ODF CTD #3, July'96 calib. +0.00075 deg.C. Two casts (stations 30 and 31) had problems with PRT1 readings, caused by a flooded sensor turret; the problem was repaired before station 32. It was necessary to use PRT2 for the primary temperature data on these two casts, despite the expected noisier salinity caused by the distance between PRT2 and the conductivity sensor. The post-cruise secondary temperature sensor laboratory calibration showed a fairly constant -1.9997 deg.C offset between -1.1 and 9 deg.C, covering the full range of temperatures seen on these two casts. This offset was applied to correct the PRT2 temperature data for stations 30 and 31. Figure 8.2.3 shows the post-cruise temperature calibration data used to correct CTD #3 PRT2 data. Figure 8.2.3 WOCE96-S4I Secondary temperature (PRT2) correction for ODF CTD #3, July'96 calib., rawPRT2 from 0.5 to 10.5 deg.C only. The pre- to post-cruise laboratory calibration shift for the primary temperature sensor on CTD #3 was less than the magnitude of the WOCE accuracy standard of 0.002 deg.C for the temperature range of the S4I line. Since the difference between the two calibrations was essentially split and applied to the data, S4I CTD temperatures should be within the WOCE accuracy specifications. PRT2 data compared well to PRT1 data throughout the cruise, and should also be within the same accuracy range as PRT1. The exception to these accuracy figures would be where uncorrected CTD temperatures cross between positive and negative values: the discontinuity described in the "CTD Data Processing" section may offset colder data. This error may be as much as +0.0025 deg.C for corrected CTD temperatures below ~-1.49 deg.C, an amount apparent in the figures for PRT1 Temperature Calibrations seen in the previous section. Fortunately, all such temperatures on S4I are shallower than 480 db and fall in areas where the temperature gradient is larger than the error, so it is not readily detectable. 8.3. CTD #3 Conductivity The corrected CTD rosette trip pressure and temperature were used with the bottle salinity to calculate a bottle conductivity. Differences between the bottle and CTD conductivities were then used to derive a conductivity correction. This correction is normally linear for the 3-cm conductivity cell used in the Mark III CTD, but CTD #3 sensors required pressure- dependent conductivity corrections as well. Three different CTD conductivity sensors were used during S4I; all three sensors were essentially new at the start of S4I. o #E55 was used on stations 1-31. It was replaced because the sensor turret leaked during stations 30-31. o #P42 was used on stations 32-38. It was replaced because of nonlinear sensitivity and lack of stability. o #E55 was again used on stations 39-61. This sensor became extremely noisy during stations 56-58. The sensor was cleaned with RBS prior to station 59, which caused a shift in the offset while significantly reducing the noise level. The sensor was replaced because of nonlinear sensitivity and lack of stability. o #O17 was used on stations 62-108. It was fairly stable, with a small shift after the 6.5-day break in station work to deliver supplies to Mirnyy. Conductivity differences above and below the thermocline were fit to CTD conductivity for each conductivity sensor to determine conductivity slopes. Stations 1-31, 39-55 and 56-61 were treated separately for sensor #E55, and stations 62-72 and 73-108 were grouped separately for sensor #O17. Figures 8.3.0.0-8.3.0.5 show the data used to determine preliminary conductivity slopes. Figure 8.3.0.0 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 1-31 (C-sensor #E55). Figure 8.3.0.1 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 32-38 (C-sensor #P42). Figure 8.3.0.2 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 39-55 (C-sensor #E55). Figure 8.3.0.3 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 56-61 (C-sensor #E55). Figure 8.3.0.4 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 62-72 (C-sensor #O17). Figure 8.3.0.5 CTD #3 prelim. conductivity slopes for WOCE96-S4I, stations 73-108 (C-sensor #O17). These preliminary conductivity differences were fit to conductivity, with outlying values (4,2 standard deviations) rejected. Shallower stations were omitted from all groups; only stations 56-58 were used to determine slopes for stations 56-61 because of the offset caused by cleaning the sensor prior to station 59. Conductivity slopes were calculated from the first-order fits. The slopes calculated for stations 1-31 and 39-55 were averaged, as were the slopes for stations 62-72 and 73-108. Preliminary slopes were then applied to each S4I cast. Once the conductivity slopes were applied, residual CTD conductivity offset values were calculated for each cast using bottle conductivities deeper than 1400 db for stations 1-31, 39-55 and 62-108. More restricted pressure ranges were used to determine preliminary offsets for casts with unstable conductivity sensors, while pressure-dependent conductivity corrections were pending: only 0-70 db differences were used for stations 32-38, and 2300-2800 db for stations 56-61. Figure 8.3.1 illustrates the S4I preliminary conductivity offset residual values. Figure 8.3.1 S4I CTD #3 preliminary conductivity offsets by station number. Casts were grouped together based on drift and/or known CTD conductivity shifts or problems to determine average offsets. This also smoothed the effect of any cast-to-cast bottle salinity variation, typically on the order of +/-0.001 PSU. Some casts were omitted from the fits because there were no bottle differences within the specified pressure ranges used, or because of known CTD shifts relative to nearby casts. Smoothed offsets were applied to each cast except stations 32-38 and 56-61, which had individual offsets applied because of sensor instabilities. Some offsets were then manually adjusted to account for discontinuous shifts in the conductivity transducer response or bottle salinities, or to maintain deep theta-salinity consistency from cast to cast. After applying preliminary conductivity slopes and offsets to each cast, residual CTD conductivity differences above and below the thermocline were fit to CTD pressure for each sensor. Stations 1-31 + 39-55 conductivity differences varied +/-0.002 mS/cm and warranted a second-order correction as a function of pressure. Stations 62-108 needed a linear correction as a function of pressure to pull in the 0.001 mS/cm differences at intermediate pressures. Stations 32-38 and 56-61 required individual second-order corrections (linear for shallow station 35) as a function of pressure to pull in much larger residual differences. Figures 8.3.2.0-8.3.2.3 show the residual conductivity differences used for determining these corrections. Figure 8.3.2.0 CTD #3 residual conductivity vs. pressure for WOCE96-S4I, stas 1-31 + 39-55 (C-sensor #E55). Figure 8.3.2.1 CTD #3 residual conductivity vs. pressure for WOCE96-S4I, stas 32-38 (C-sensor #P42). Figure 8.3.2.2 CTD #3 residual conductivity vs. pressure for WOCE96-S4I, stas 56-61 (C-sensor #E55). Figure 8.3.2.3 CTD #3 residual conductivity vs. pressure for WOCE96-S4I, stas 62-108 (C-sensor #O17). After applying the pressure-dependent corrections to conductivity, conductivity slopes were re-examined for any leftover dependence on conductivity. Two groups needed minor adjustments to conductivity slopes as a function of conductivity. Figures 8.3.3.0 and 8.3.3.1 show the residual corrections calculated for stations 55-61 and stations 62-108. Figure 8.3.3.0 CTD #3 adjustments to conductivity slopes for WOCE96-S4I, stas 55-61 (C-sensor #E55). Figure 8.3.3.1 CTD #3 adjustments to conductivity slopes for WOCE96-S4I, stas 62-108 (C-sensor #O17). The final S4I pressure-dependent coefficients and conductivity-dependent slopes are summarized in Figures 8.3.4 and 8.3.5. Figure 8.3.6 summarizes the final conductivity offsets (combined conductivity- and pressure- dependent corrections) by station number. Figure 8.3.4 S4I CTD #3 pressure-dependent correction coefficients by station number. Figure 8.3.5 S4I CTD #3 conductivity-dependent slope corrections by station number. Figure 8.3.6 S4I CTD #3 combined conductivity offsets by station number. S4I temperature and conductivity correction coefficients are also tabulated in Appendix A. Summary of Residual Salinity Differences Figures 8.3.7, 8.3.8, 8.3.9 and 8.3.10 summarize the S4I residual differences between bottle and CTD salinities after applying the conductivity corrections. Only CTD and bottle salinities with final quality code 2 (acceptable) were used to generate these figures and statistics. Residual differences exceeding +/- 0.025 PSU are included in the calculations for averages and standard deviations, even though they arenot plotted. Figure 8.3.7 S4I Salinity residual differences vs pressure (after correction). Figure 8.3.8 S4I Salinity residual differences vs station # (after correction). Figure 8.3.9 S4I Deep salinity residual differences vs station # (after correction). The CTD conductivity calibration represents a best estimate of the conductivity field throughout the water column. 3-sigma from the mean residual in Figures 8.3.8 and 8.3.9, or +/- 0.0059 PSU for all salinities and +/- 0.0015 PSU for deep salinities, represents the limit of repeatability of the bottle salinities (Autosal, rosette, operators and samplers). This limit agrees with station overlays of deep theta-salinity. Within most casts (a single salinometer run), the precision of bottle salinities and CTD salinities appears to be better than 0.001 PSU. Final calibrated CTD data from WOCE96-S4I and various cruises were compared at their closest stations. Non-S4I WOCE data were extracted from http://whpo.ucsd.edu in March 2003. A table of the comparisons follows: Table 8.3.10 S4I Compared To Historical Data S4I |Crs.ID/ |Crs. |IAPSO SSW |Distance |Avg. Salinity Diffc. (Crs-S4I) Sta.No. |Sta.No. |Date |Batch No. |Apart(nm) |(PSU at Deepest 1 deg.C Theta) --------|----------------|-------|----------|----------|------------------------------------- 1 |WOCE-S4A/20 |Mar.96 |P-127 |68 |0 to +0.001 (vs. S4A btls - |(06AQANTXIII_4) | | | |CTD salinity quality-coded 4) --------|----------------|-------|----------|----------|------------------------------------- 63,64 |WOCE-I8S/76 |Dec.94 |P-124 |13,27 |+0.001 92 |WOCE-I9S/92 |Jan.95 |P-124 |9 |+0.001 |(316N145_5) | | | | --------|----------------|-------|----------|----------|------------------------------------- 105 |WOCE-S3+S4/17 |Jan.95 |P-123 |9 |+0.003 to +0.0035 106 |WOCE-S3+S4/18 |Jan.95 |P-123 |12 |+0.0005 to +0.002 107 |WOCE-S3+S4/3-4 |Dec.94 |P-123 |14 |+0.006 to +0.007 * 108 |WOCE-S3+S4/2 |Dec.94 |P-123 |0.5 |+0.001 to +0.002 108 |WOCE-S3+S4/19 |Jan.95 |P-123 |0.1 | 0 (0.5+ deg.C Theta) to +0.004 (deep) |(09AR9404_1) | | | | --------|----------------|-------|----------|----------|------------------------------------- 11 |WOCE-S4/12345 |Feb.93 |P-120 |46 |-0.002 (below -0.04 deg.C Theta) | | | | |-0.0005 (-0.04 to 0.45 deg.C Theta) 86 |WOCE-S4/12351 |Feb.93 |P-120 |21 |-0.004 (S4I 300m shallower than S4) |(74DI200_1) | | | | --------|----------------|-------|----------|----------|------------------------------------- 48,49 |GEOSECS/430 |Feb.78 |P-61 |201,188 |+0.004/+0.003 85 |GEOSECS/431 |Feb.78 |P-61 |76 |+/-0.002 above 0.2 deg.C Theta | | | | |(incomparable deeper) 88,89 |GEOSECS/430 |Feb.78 |P-61 |180,178 |+0.002 * these S3+S4 casts were +0.003 to +0.0045 PSU compared to nearby casts on the same cruise IAPSO Standard Seawater batch corrections are similar for S4I (P-125) and most of the standards used for the other cruises listed in the chart: at most, -0.0004 PSU in salinity. The P-123/P-125 batch difference may account for up to a +0.001 PSU difference between S3+S4/S4I salinity data [Culk98]. S4A stations 3-4 are probably not good for comparison, since they are offset from nearby casts on the same cruise. S4I stations 105-108 all agree within +/- 0.0005 PSU. IAPSO batch corrections would bring the GEOSECS data about 0.001 PSU closer to S4I [Mant87] [Culk98]. 8.4. CTD Dissolved Oxygen SensorMedics oxygen sensors have a finite shelf life, so new sensors are usually employed at the start of a cruise. A single, new O2 sensor was used throughout S4I. The pressure-related response problems observed during WOCE95-I10 were not apparent during this leg. The oxygen sensor from this cruise was used again 8 months later, during WOCE97-ICM3 at 20S. The extremely cold temperatures during S4I apparently caused problems with the CTD O2 fits, since no fitting problems occurred for this same sensor on ICM3. Either the surface mixed layer fit the bottle oxygen data, causing arelatively shapeless deeper fit; or the deeper data fit the bottle-defined structure well at the expense of surface fits. Since freezing problems at the surface were observed with temperature and conductivity sensors, it is likely that the oxygen sensor was also affected. Most surface oxygen fits were sacrificed in order to define sub-thermocline CTD O2 structure; these poorly fit areas are documented in Appendix C, and the data are quality- coded 3 or 4. There are a number of problems with the response characteristics of the SensorMedics O2 sensor used in the NBIS Mark III CTD, the major ones being a secondary thermal response and a sensitivity to profiling velocity. Stopping the rosette for as little as half a minute, or slowing down for a bottom approach, can cause shifts in the CTD O2 profile as oxygen becomes depleted in water near the sensor. Such shifts could usually be corrected by offsetting the raw oxygen data from the stop or slow-down area until some time after the sensor has been moving again, occasionally until the bottom of the cast. All offset sections, winch stops or slow-downs that affected CTD oxygen data are documented in Appendix C. Because of these same stop/slow-down problems, up-cast CTD O2 data cannot be optimally calibrated to O2 check samples. Instead, down-cast CTD O2 data are derived by matching the up-cast rosette trips along isopycnal surfaces. When down-casts were deemed to be unusable (see Appendix C), up- cast CTD O2 data were processed despite the signal drop-offs typically seen at bottle stops. The differences between CTD O2 data modeled from these derived values and check samples are then minimized using a non-linear least-squares fitting procedure. Figures 8.4.0 and 8.4.1 show the residual differences between the corrected CTD O2 and the bottle O2 (ml/l) for each station. Only CTD and bottle oxygens with final quality code 2 (acceptable) were used to generate these figures and statistics. Residual differences exceeding +/- 0.5 ml/l are included in the calculations for averages and standard deviations, even though they are not plotted. Figure 8.4.0 S4I O2 residual differences vs station # (after correction). Figure 8.4.1 S4I Deep O2 residual differences vs station # (after correction). The standard deviations of 0.044 ml/l for all oxygens and 0.015 ml/l for deep oxygens are only intended as indicators of how well the up-cast bottle and pressure-series (mostly down-cast) CTD O2 values match up. ODF makes no claims regarding the precision or accuracy of CTD dissolved O2 data. The general form of the ODF O2 conversion equation follows Brown and Morrison [Brow78] and Millard [Mill82], [Owen85]. ODF does not use a digitized O2 sensor temperature to model the secondary thermal response but instead models membrane and sensor temperatures by low-pass filtering the PRT temperature. In situ pressure and temperature are filtered to match the sensor response. Time-constants for the pressure response Taup, and two temperature responses TauTs and TauTf are fitting parameters. The Oc gradient, dOc/dt, is approximated by low-pass filtering 1st-order Oc differences. This gradient term attempts to correct for reduction of species other than O2 at the cathode. The time-constant for this filter, Tauog, is a fitting parameter. Oxygen partial-pressure is then calculated: Opp=[c1*Oc+c2]*fsat(S,T,P)*e**(c3*Pl+c4*Tf+c5*Ts+c6*dOc/dt) (8.4.0) where: Opp = Dissolved O2 partial-pressure in atmospheres (atm); Oc = Sensor current (uamps); fsat(S,T,P) = O2 saturation partial-pressure at S,T,P (atm); S = Salinity at O2 response-time (PSUs); T = Temperature at O2 response-time (deg.C); P = Pressure at O2 response-time (decibars); Pl = Low-pass filtered pressure (decibars); Tf = Fast low-pass filtered temperature (deg.C); Ts = Slow low-pass filtered temperature (deg.C); dOc/dt = Sensor current gradient (uamps/secs). S4I CTD O2 correction coefficients (c1 through c6) are tabulated in Appendix B. 9. Bottle Sampling At the end of each rosette deployment, water samples were drawn from the bottles in the following order: o CFCs; o 3He; o O2; o PCO2; o Total CO2; o AMS 14C; o Nutrients; o Salinity; o 18O/16O; o Tritium; o Alkalinity. Since some properties were not sampled on every cast, the actual sample- drawing sequence was modified as necessary. The correspondence between individual sample containers and the rosette bottle from which the sample was drawn was recorded on the sample log for the cast. This log also included any comments or anomalous conditions noted about the rosette and bottles. One member of the sampling team was designated the sample cop, whose sole responsibility was to maintain this log and insure that sampling progressed in the proper drawing order. Normal sampling practice included opening the drain valve and then the air vent on the bottle, indicating an air leak if water escaped. This observation together with other diagnostic comments (e.g., "lanyard caught in lid", "valve left open") that might later prove useful in determining sample integrity were routinely noted on the sample log. Drawing oxygen samples also involved taking the sample draw temperature from the bottle. The temperature was noted on the sample log and was sometimes useful in determining leaking or mis-tripped bottles. Once individual samples had been drawn and properly prepared, they were distributed to their respective laboratories for analysis. Oxygen, nutrients and salinity analyses were performed on computer-assisted (PC) analytical equipment networked to Sun SPARCstations for centralized data analysis. The analysts for each specific property were responsible for insuring that their results were updated into the cruise database. 10. Bottle Data Processing Bottle data processing began with sample drawing, and continued until the data were considered to be final. One of the most important pieces of information, the sample log sheet, was filled out during the drawing of the many different samples. It was useful both as a sample inventory and as a guide for the technicians in carrying out their analyses. Any problems observed with the rosette before or during the sample drawing were noted on this form, including indications of bottle leaks, out-of-order drawing, etc. Oxygen draw temperatures recorded on this form were at times the first indicator of rosette bottle-tripping problems. Additional clues regarding bottle tripping or leak problems were found by individual analysts as the samples were analyzed and the resulting data were processed and checked. The next stage of processing was accomplished after the individual parameter files were merged into a common station file, along with CTD- derived parameters (pressure, temperature, conductivity, etc.). The rosette cast and bottle numbers were the primary identification for all ODF-analyzed samples taken from the bottle, and were used to merge the analytical results with the CTD data associated with the bottle. At this stage, bottle tripping problems were usually resolved, sometimes resulting in changes to the pressure, temperature and other CTD properties associated with the bottle. All CTD information from each bottle trip (confirmed or not) was retained in a file, so resolving bottle tripping problems consisted of correlating CTD trip data with the rosette bottles. Diagnostic comments from the sample log, and notes from analysts and/or bottle data processors were entered into a computer file associated with each station (the "quality" file) as part of the quality control procedure. Sample data from bottles suspected of leaking were checked to see if the properties were consistent with the profile for the cast, with adjacent stations, and, where applicable, with the CTD data. Various property- property plots and vertical sections were examined for both consistency within a cast and consistency with adjacent stations by data processors, who advised analysts of possible errors or irregularities. The analysts reviewed and sometimes revised their data as additional calibration or diagnostic results became available. Based on the outcome of investigations of the various comments in the quality files, WHP water sample codes were selected to indicate the reliability of the individual parameters affected by the comments. WHP bottle codes were assigned where evidence showed the entire bottle was affected, as in the case of a leak, or a bottle trip at other than the intended depth. WHP water bottle quality codes were assigned as defined in the WOCE Operations Manual [Joyc94] with the following additional interpretations: 2 | No problems noted. 3 | Leaking. An air leak large enough to produce an | observable effect on a sample is identified by a code of | 3 on the bottle and a code of 4 on the oxygen. (Small | air leaks may have no observable effect, or may only | affect gas samples.) 4 | Did not trip correctly. Bottles tripped at other than | the intended depth were assigned a code of 4. There may | be no problems with the associated water sample data. 5 | Not reported. No water sample data reported. This is a | representative level derived from the CTD data for | reporting purposes. The sample number should be in the | range of 80-99. 9 | The samples were not drawn from this bottle. WHP water sample quality flags were assigned using the following criteria: 1 | The sample for this measurement was drawn from the water | bottle, but the results of the analysis were not (yet) | received. 2 | Acceptable measurement. 3 | Questionable measurement. The data did not fit the | station profile or adjacent station comparisons (or | possibly CTD data comparisons). No notes from the | analyst indicated a problem. The data could be | acceptable, but are open to interpretation. 4 | Bad measurement. The data did not fit the station | profile, adjacent stations or CTD data. There were | analytical notes indicating a problem, but data values | were reported. Sampling and analytical errors were also | coded as 4. 5 | Not reported. There should always be a reason | associated with a code of 5, usually that the sample was | lost, contaminated or rendered unusable. 9 | The sample for this measurement was not drawn. WHP water sample quality flags were assigned to the CTDSAL (CTD salinity) parameter as follows: 2 | Acceptable measurement. 3 | Questionable measurement. The data did not fit the | bottle data, or there was a CTD conductivity calibration | shift during the up-cast. 4 | Bad measurement. The CTD up-cast data were determined | to be unusable for calculating a salinity. 7 | Despiked. The CTD data have been filtered to eliminate | a spike or offset. WHP water sample quality flags were assigned to the CTDO (CTD O2) parameter as follows: 1 | Not calibrated. Data are uncalibrated. 2 | Acceptable measurement. 3 | Questionable measurement. 4 | Bad measurement. The CTD data were determined to be | unusable for calculating a dissolved oxygen | concentration. 5 | Not reported. The CTD data could not be reported, | typically when CTD salinity is coded 3 or 4. 7 | Despiked. The CTD data have been filtered to eliminate | a spike or offset. 9 | Not sampled. No operational CTD O2 sensor was present | on this cast. Note that CTDO values were derived from the down-cast pressure-series CTD data, except for 18 stations where up-casts were processed because of conductivity problems on the down-casts. CTD data were matched to the up- cast bottle data along isopycnal surfaces. If the CTD salinity is footnoted as bad or questionable, the CTD O2 is not reported. Table 10.0 shows the number of samples drawn and the number of times each WHP sample quality flag was assigned for each basic hydrographic property: Table 10.0 Frequency of WHP quality flag assignments for S4I. Rosette Samples Stations 001-108 ---------------------------------------------------------------------------- Reported WHP Quality Codes Levels 1 2 3 4 5 7 9 ----------||---------|------------------------------------------------------ Bottle || 3655 | 0 3542 1 108 0 0 4 CTD Salt || 3655 | 0 3493 0 36 0 126 0 CTD Oxy || 3619 | 0 2909 111 599 36 0 0 Salinity || 3604 | 0 3521 24 59 9 0 42 Oxygen || 3630 | 0 3568 33 29 7 0 18 Silicate || 3640 | 0 3638 1 1 0 0 15 Nitrate || 3640 | 0 3639 0 1 0 0 15 Nitrite || 3640 | 0 3639 0 1 0 0 15 Phosphate || 3640 | 0 3602 3 35 0 0 15 Additionally, all WHP water bottle/sample quality code comments are presented in Appendix D. 11. Pressure and Temperatures All pressures and temperatures for the bottle data tabulations on the rosette casts were obtained by averaging CTD data for a brief interval at the time the bottle was closed on the rosette, then correcting the data based on CTD laboratory calibrations. The temperatures are reported using the International Temperature Scale of 1990. 12. Salinity Analysis Equipment and Techniques Two Guildline Autosal Model 8400A salinometers were available for measuring salinities. The salinometers were modified by ODF and contained interfaces for computer-aided measurement. Autosal #57-396 was a backup unit but was not used on this expedition. Autosal #55-654 was used to measure salinity on all stations. Its water bath temperature was set and maintained at 24 deg.C for all runs except stations 32-39, where the bath temperature was set at 21 deg.C. The salinity analyses were performed when samples had equilibrated to laboratory temperature, within 7-28 hours after collection. The salinometer was standardized for each group of analyses (typically one cast, usually 36 samples) using two fresh vials of standard seawater per group. A computer (PC) prompted the analyst for control functions such as changing sample, flushing, or switching to "read" mode. At the correct time, the computer acquired conductivity ratio measurements, and logged results. The sample conductivity was redetermined until readings met software criteria for consistency. Measurements were then averaged for a final result. Unstable readings were encountered during analysis of the first 5 samples from station 42. The Autosal flow cell was cleaned, and sample analysis was resumed ~10 hours later without further problems. Sampling and Data Processing Salinity samples were drawn into 200 ml Kimax high-alumina borosilicate bottles, which were rinsed three times with sample 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 collecting each sample, inserts were inspected for proper fit and loose inserts were replaced to insure an airtight seal. The draw time and equilibration time were logged for all casts. Laboratory temperatures were logged at the beginning and end of each run. PSS-78 salinity [UNES81] was calculated for each sample from the measured conductivity ratios. The difference (if any) between the initial vial of standard water and one run at the end as an unknown was applied linearly to the data to account for any drift. The data were added to the cruise database. 3604 salinity measurements were made and 233 vials of standard water were used. The estimated accuracy of bottle salinities run at sea is usually better than 0.002 PSU relative to the particular standard seawater batch used. Laboratory Temperature The temperature stability in the salinometer laboratory was fair, ranging from 18.7 to 25.8 deg.C and drifting an average of 0.5 deg.C during a run of samples. The laboratory temperature was between -4 and +2 deg.C of the Autosal bath temperature during all sample runs. Standards IAPSO Standard Seawater (SSW) Batch P-125 was used to standardize the salinometers. 13. Oxygen Analysis Equipment and Techniques Dissolved oxygen analyses were performed with an ODF-designed automated oxygen titrator using photometric end-point detection based on the absorption of 365nm wavelength ultra-violet light. The titration of the samples and the data logging were controlled by PC software. Thiosulfate was dispensed by a Dosimat 665 buret driver fitted with a 1.0 ml buret. ODF used a whole-bottle modified-Winkler titration following the technique of Carpenter [Carp65] with modifications by Culberson et al. [Culb91], but with higher concentrations of potassium iodate standard (approximately 0.012N) and thiosulfate solution (50 gm/l). Carbon disulfide was added to the thiosulfate as a preservative. Standard solutions prepared from pre- weighed potassium iodate crystals were run at the beginning of each session of analyses, which typically included from 1 to 3 stations. Nine standards were made up during the cruise and compared to assure that the results were reproducible, and to preclude the possibility of a weighing or dilution error. Reagent/distilled water blanks were determined, to account for presence of oxidizing or reducing materials. Sampling and Data Processing Samples were collected for dissolved oxygen analyses soon after the rosette sampler was brought on board, and after samples for CFCs and helium were drawn. Using a Tygon drawing tube, nominal 125ml volume-calibrated iodineflasks were rinsed twice with minimal agitation, then filled and allowed to overflow for at least 3 flask volumes. The sample draw temperature was measured with a small platinum resistance thermometer embedded in the drawing tube. Reagents were added to fix the oxygen before stoppering. The flasks were shaken twice to assure thorough dispersion of the precipitate, once immediately after drawing, and then again after about 20 minutes. The samples were analyzed within 1-9 hours of collection (18 hours for station 1 only), and then the data were merged into the cruise database. Thiosulfate normalities were calculated from each standardization and corrected to 20 deg.C. The 20 deg.C normalities and the blanks were plotted versus time and were reviewed for possible problems. New thiosulfate normalities were recalculated after the blanks had been smoothed as a function of time, if warranted. These normalities were then smoothed, and the oxygen data were recalculated. Oxygens were converted from milliliters per liter to micromoles per kilogram using the in situ temperature. Sample temperatures were measured at the time the samples were drawn from the rosette bottle. These temperatures were useful in indicating whether or not a bottle tripped properly. 3630 oxygen measurements were made, with no major problems encountered during the analyses. 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 bottle 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. Standards Potassium iodate standards, nominally 0.44 gram, were pre-weighed in ODF's chemistry laboratory to +/-0.0001 grams. The exact normality was calculated at sea after the volumetric flask volume and dilution temperature were known. Potassium iodate was obtained from Johnson Matthey Chemical Co. and was reported by the supplier to be >99.4% pure. All other reagents were "reagent grade" and were tested for levels of oxidizing and reducing impurities prior to use. 14. Nutrient Analysis Equipment and Techniques Nutrient analyses (phosphate, silicate, nitrate and nitrite) were performed on an ODF-modified 4-channel Technicon AutoAnalyzer II, generally within a few hours after sample collection. Occasionally samples were refrigerated up to a maximum of 8 hours at 2-6 deg.C. All samples were brought to room temperature prior to analysis. The methods used are described by Gordon et al. [Gord93]. The analog outputs from each of the four channels were digitized and logged automatically by computer (PC) at 2-second intervals. Silicate was analyzed using the technique of Armstrong et al. [Arms67]. An acidic solution of 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. Tartaric acid was also added to impede PO4 color development. The sample was passed through a 15mm flowcell and the absorbance measured at 660nm. A modification of the Armstrong et al. [Arms67] procedure was used for the analysis of nitrate and nitrite. For the nitrate analysis, the seawater sample was passed through a cadmium reduction column where nitrate was quantitatively reduced to nitrite. Sulfanilamide was introduced to the sample stream followed by N-(1-naphthyl)ethylenediamine dihydrochloride which coupled to form a red azo dye. The stream was then passed through a 15mm flowcell and the absorbance measured at 540nm. The same technique was employed for nitrite analysis, except the cadmium column was bypassed, and a 50mm flowcell was used for measurement. Phosphate was analyzed using a modification of the Bernhardt and Wilhelms [Bern67] technique. An acidic solution of ammonium molybdate was added to the sample to produce phosphomolybdic acid, then reduced to phosphomolybdous acid (a blue compound) following the addition of dihydrazine sulfate. The reaction product was heated to ~55 deg.C to enhance color development, then passed through a 50mm flowcell and the absorbance measured at 820nm. Sampling and Data Processing Nutrient samples were drawn into 45 ml polypropylene, screw-capped "oak- ridge type" centrifuge tubes. The tubes were cleaned with 10% HCl and rinsed with sample twice before filling. Standardizations were performed at the beginning and end of each group of analyses (typically one cast, usually 36 samples) with an intermediate concentration mixed nutrient standard prepared prior to each run from a secondary standard in a low- nutrient seawater matrix. The secondary standards were prepared aboard ship by dilution from primary standard solutions. Dry standards were pre- weighed at the laboratory at ODF, and transported to the vessel for dilution to the primary standard. Sets of 6-7 different standard concentrations were analyzed periodically to determine any deviation from linearity as a function of concentration for each nutrient analysis. A correction for non-linearity was applied to the final nutrient concentrations when necessary. After each group of samples was analyzed, the raw data file was processed to produce another file of response factors, baseline values, and absorbances. Computer-produced absorbance readings were checked for accuracy against values taken from a strip chart recording. The data were then added to the cruise database. 3640 nutrient samples were analyzed. No major problems were encountered with the measurements. The pump tubing was changed four times, and deep seawater was run as a substandard check. The temperature stability of the laboratory used for the analyses was good, ranging from 20 to 24 deg.C. Nutrients, reported in micromoles per kilogram, were converted from micromoles per liter by dividing by sample density calculated at 1 atm pressure (0 db), in situ salinity, and an assumed laboratory temperature of 25 deg.C. Standards The silicate primary standard (Na2SiF6) was obtained from Aesar and was reported by the suppliers to be >98% pure. The nitrite (NaNO2) primary standard was obtained from GFS and was reported by the suppliers to be >97% pure. Primary standards for nitrate (KNO3) and phosphate (KH2PO4) were obtained from Johnson Matthey Chemical Co., and the supplier reported purities for each of 99.999%. B. Underway Measurements B1. Navigation and Bathymetry Navigation data were acquired from the ship's Ashtech GPS receiver via the network. They were logged automatically at one-minute intervals by one of the Sun Sparcstations. Underway bathymetry was logged manually from the ship's 12 kHz Raytheon/EPC PDR at five-minute intervals (or when possible in the ice), then merged with the navigation data to provide a time-series of underway position, course, speed and bathymetry data. These data were used for all station positions, PDR depths, and for bathymetry on vertical sections (Carter, 1980). Depth data on the transit from Cape Town to station 1, and from station 108 to Hobart were not logged. Data on station were not logged. B2. Meteorological Observations Five-minute average meteorological data are routinely recorded by the Palmer. Data recorded consist of time, position, air temperature, relative humidity, wet-bulb temperature, PSR, PIR, barometric pressure, and wind speed and direction. Data were recorded continuously from Cape Town to Hobart. Significant data gaps (longer than 20 minutes, but less than 32 minutes in all cases) occurred on 19 and 27 May, and 1,2,4,7,20 and 24 June. B3. Hull-mounted Acoustic Doppler Current Profiler (S. Rutz) Ocean velocity observations were taken using a hull-mounted Acoustic Doppler Current Profiler (ADCP) system and GPS navigation data. Data were recorded from May 3, 1995 to July 4, 1996 between Capetown, South Africa and Hobart, Australia, along the nominal latitude of 62°S from 20°E to 120°E with two transects across the Antarctic continental slope. The purpose of the observations was to document the upper ocean horizontal velocity structure along the cruise track. The observations provide absolute velocity estimates including the ageostrophic component of the flow. Fig. 2 shows the cruise track and the near-surface currents measured by the ADCP. The hull-mounted ADCP is part of the ship's equipment aboard the Palmer. The ADCP is a 150 kHz unit manufactured by RD Instruments. The instrument pings about once per second, and for most of the cruise the data were stored as 100- second averages or ensembles. The user-exit program, ue4, receives and stores the ADCP data along with both the P-code navigation data from a Trimble receiver and the positions from an Ashtech gps receiver. The ship gyro provided heading information for vector averaging the ADCP data over the 100- second ensembles. The user-exit program calculates and stores the heading offset based on the difference between the heading determination from the Ashtech receiver and from the ship gyro. The ADCP transducer is mounted in a glycol bath at a depth of about 7 meters below the sea surface. As setup parameters, a blanking interval of 16 meters, a vertical pulse length of 16 meters, a vertical bin size of 8 meters, and 60 bins were used. A 300- second sampling interval was used at the beginning of the cruise and the interval was decreased to 100-seconds shortly after entering pack ice to increase the amount of usable data (cruising through ice severely limited the percent of good return pings). 100-seconds was the sampling interval for the remainder of the cruise. Bottom tracking was activated during the shallow water transits near South Africa, Antarctica, and Tasmania. For the processing of the ADCP data aboard ship, a rotation amplitude of 0.97, a rotation angle of -1.65 degrees (added to the gyro minus gps heading), and a time filter width of one hour were used. Final editing and calibration of the ADCP data has not yet been done. For example, some spikes due to pinging off the CTD wire or rosette on station are still present in the data. A set of preliminary plots was generated during the cruise. The plots display velocity vectors averaged over several depth intervals, and over one hour in time. The velocity was measured from a depth of 23 meters to a depth of about 500 meters. During the first few weeks of the cruise, the ADCP hung a half-dozen times for unknown reasons. Several measures were taken to prevent this (e.g., the keyboard was locked) or to minimize its effect (e.g., a "watch dog" program was installed that would reboot the PC if it hung for more than about five minutes). These measures were mostly successful though the ADCP did hang one more time for unexplained reasons late in the cruise. A Trimble P-code receiver was used for navigation. The data from the receiver was stored once per second for the entire cruise. The Ashtech receiver uses a four antennae array to measure position and attitude. The heading estimate was used with the ship gyro to provide a heading correction for the ADCP ensembles. The Ashtech data was stored by the ADCP user-exit program along with the ADCP data. The Ashtech receiver at times (especially after it had been reset) could not lock onto enough satellites to determine the ship's heading. This was remedied by temporarily disabling certain satellites that were low on the horizon so that the Ashtech would not waste its time in a futile attempt to lock onto them. Also, the ship gyro input to the ADCP hung about two dozen times during the cruise for intervals ranging from several minutes to hours. The hangs were mostly due to the ship's data acquisition system (DAS) crashing. An attempt to feed the ship gyro directly to the ADCP, bypassing the DAS, was unsuccessful and had some unintended consequences (i.e., the auto-pilot went berserk). B4. Atmospheric Chemistry (D. Chipman and M. Mensch) Air samples for analysis were drawn from a single inlet located just forward of the ship's bridge through a continuous run of 3/8 inch diameter Dekoron tubing. A KNF Neuberger pump with a teflon-covered rubber diaphragm was use to pressurize the air for distribution to the CO2 analysis system in the Hydro Lab and the CFC analysis system in the Dry Lab. A vent line with a needle valve from a tee fitting at the CFC system provided backpressure for the line while allowing it to be continuously flushed with fresh atmospheric air. CO2 Analysis The LDEO underway pCO2 analysis system was used to determine the concentration of CO2 in dried atmospheric air. At intervals of approximately one half hour, air from the atmospheric sampling line was allowed to flow through a countercurrent-flow permeation gas dryer and then through the cell of the Licor infrared gas analyzer for three minutes at a flow rate of 25-35 ml/min. The sample flow was stopped for 20 seconds prior to reading the analyzer output, to allow time for the pressure to vent to the atmospheric value and for the sample to come to cell temperature. Immediately following each atmospheric sample, the instrument was calibrated using a set of four compressed air-CO2 mixtures (which have CO2 concentrations traceable to the WMO scale of C.D. Keeling); a second- order polynomial response curve was fitted to the instrumental signals given by these gases and used to calculate the concentration of CO2 in the sample. Atmospheric measurements were made whenever the pCO2 analysis system was operating, which was essentially continuously in open water and periodically (usually at stations only) when operating in the ice. Because of the problem of contamination with stack gas when the relative wind was from behind the ship, only those analyses made when the ship's meteorological monitoring system indicated relative winds from ahead were considered valid and retained. CFC Analysis Marine air samples for CFC analysis were taken from the bow air line immediately in front of the T-fitting leading to the vent line. The air was dried by flowing through magnesium perchlorate and then analyzed in exactly the same way standard gases were measured (Section C7). Marine air was analyzed whenever the necessary time was available and the relative wind direction was from the bow. The results will provide information about the current atmospheric CFC levels and will allow the calculation of the CFC saturation levels in the surface water. B5. Thermosalinograph and underway pCO2 (D. Chipman) The Palmer is fitted with two separate uncontaminated seawater lines- a 1-inch line of stainless steel and PVC, which supplies the thermosalinograph and other instruments in the Hydro Lab, and a 2-inch stainless steel line which provides water to the Aquarium Lab. Both have inlets located at a depth of approximately 6.7 meters, well aft of the bow to reduce the entrainment of air and ice during icebreaking operations. Due to a failure of the pump on the thermosalinograph line about one third of the way through the cruise, the thermosalinograph and underway pCO2 equilibrator were replumbed to be supplied water from the larger seawater line. Both lines were plagued with blockages due to ice entrainment during operations in the heavy ice, especially when snow-covered, and in general uncontaminated seawater was only available when operating in open water or unconsolidated floes, or when on station within the ice. The ship is fitted with a Seabird Model SBE-21 thermosalinograph, located in the Hydro Lab, operated and maintained by ASA personnel. The unit is provided with a remote temperature sensor located near the inlet of the smaller uncontaminated seawater line, to provide an approximate sea surface temperature. Data are logged continuously during operation by the ship's RTDAS. Due to the failure of the pump on the thermosalinograph line, the thermosalinograph received water from the other seawater line during most of the cruise, and the remote temperature was thus unavailable. A very approximate underway surface temperature during the later part of the cruise was calculated using an offset from the thermosalinograph temperature, calibrated against CTD mixed-layer temperatures during station work and against bucket thermometer temperatures during the transit from the last station to Hobart. Although the seawater line in the Hydro Lab is provided with a vortex-type debubbler, it is plumbed in parallel with the thermosalinograph, and water for the latter instrument is not routinely debubbled. Near the beginning of the cruise it became obvious that the very high noise level on the thermosalinograph salinity channel was caused by entrained air in the seawater line and the unit was replumbed to receive water from the outlet of the debubbler, which reduced the noise appreciably. Underway pCO2 Underway measurements of the surface seawater pCO2 were made using a shower-type seawater-air equilibrator similar to that originally designed by Takahashi (Broecker and Takahashi, 1966). Seawater from the same uncontaminated pumped water line which supplies the ship's thermosalinograph was used as a source for the CO2 equilibrator. The equilibrator was located downstream of a vortex debubbler to remove air entrained with the water. Air was continuously recirculated through the headspace of the equilibrator by means of a small air pump, and aliquots of this air were removed for analysis using a Licor infrared analyzer built into a fully automated analysis system. Sample gases were dried by means of a countercurrent-flow permeation gas dryer immediately prior to analysis. After eight samples of equilibrated air were analyzed, a single sample of atmospheric air pumped from a sampling point just ahead of the ship's bridge was similarly dried and analyzed. This was followed by calibration of the instrument using four air-CO2 mixtures (150 to 450 ppm range) which are traceable to the WMO calibration scale of C. D. Keeling of SIO. Barometric pressure (essentially the same as the pressure of equilibration) was measured at the time of each analysis by means of an AIR electronic barometer, and the temperature of equilibration was measured at the same time by means of a platinum resistance thermometer within the equilibrator, calibrated against a NIST-traceable mercury thermometer. The entire cycle of eight equilibrated air samples, one atmospheric air sample, and four calibration gases required approximately one half hour, and was repeated continuously. Measurements were made whenever the ship was in open water outside the territorial waters of the Republic of South Africa or Australia, and to a limited extent while operating within the ice (due to the clogging of the seawater lines during ice operations). C. Tracers C1. Chlorofluorocarbon Analysis (M. Mensch) The CFC analysis on board as well as the sampling in flame-sealed glass ampoules for subsequent on-shore analysis were performed by Guy Mathieu and Manfred Mensch (Lamont-Doherty Earth Observatory of Columbia University, New York, PI Bill Smethie) and by Steve Covey (University of Washington, Seattle, PI Mark Warner). The CFC lab was set up in the aft dry lab (N.B. Palmer room # 905). This room was not optimal for the operation of the CFC measurement systems: o There is no temperature control. This caused large long-term temperature drifts. o Whenever the outside door of the Baltic Room was open, the only access to the Baltic Room was through the aft dry lab giving rise to considerable short-term temperature and pressure fluctuations. o The "fresh" air supply to this lab consisted at least partly of recirculated air bearing the danger of serious contamination. The equipment was provided by Lamont-Doherty Earth Observatory. Two gas chromatographic measurement systems, both designed and constructed at L-DEO, were used. Both systems use the same technique for gas and water sample preparation, purification and concentration prior to injection into the chromatographic separation columns. The two systems were based on different chromatographic pre-columns and analytical columns for the separation of the CFCs from more slowly eluting compounds (pre-column) and from each other (analytical column). Both systems were configured to measure CFC11, CFC12, CFC113; system 1 also measured CCl4. On system 1, a capillary pre-column and analytical column (DB VRX, length 18 m and 57 m, respectively, film thickness 5 µm, I.D. 530 µm) were used. Both columns were held in the oven of an HP8950 GC at 90°C for the first 9.1 minutes of the run. After the complete elution of CCl4, the temperature was ramped up to 110°C within 0.5 min to clean the columns. The detector was operated at a temperature of 280°C. To minimize analysis time, pressure ramping was also used. A relatively high pressure of 110 kPa during the first minute of each run rapidly transferred the CFCs from the trap to the pre-column. The pressure was lowered to 70 kPa during the next minute and held at that level for 4.5 minutes. Then it was raised back to 110 kPa within 2 minutes. The total length of the chromatographic run was 11 minutes. The analysis took about 15 minutes per sample. System 2 used packed columns: a pre column of 80-100 mesh Porasil B packed in 40-inch stainless steel tubing with 0.085-inch I.D., and an analytical column of 60-80 mesh Carbograph 1AC packed in 5-ft stainless steel tubing with 0.085- inch I.D. Both were held at 80°C in the oven of a Shimadzu GC 8A, the detector temperature was 260°C. The analysis time per sample was about 11 min with 8 min being used for the chromatographic run. To avoid interference of N2O with CFC12, N2O was suppressed on both systems by 80-100 mesh mol sieve 5A packed into 4 in of 0.085-inch I.D. stainless steel tubing. The mol sieve was operated at about 50°C. The mol sieve was placed between the analytical column and the detector. It was valved out of the gas stream before the elution of CFC11. Based on the originally-proposed cruise track with 1 station every 30 nm it was planned to obtain 30 samples on every other station for analysis on system 2 and at least 18 samples out of the deep part of the water column on the stations in between for analysis on system 1. As the cruise progressed, this plan was adapted to the variable station spacing, bottom depth, weather and sea ice situation and other factors. Sample collection Water samples were drawn into 100-ml precision ground glass syringes directly from the 10-l Niskin-type bottles before any other samples. Close ended Luerlock fittings were used to seal filled syringes. The samples were kept under slightly positive pressure by applying a rubber band around the syringe barrel. Because of the loss of the primary rosette during a test cast, the 10-l bottles on the back-up rosette could not be tested for their CFC blank levels. By the time the spare rosette was ready for deployment, the ship was already close to the first station and in an oceanic region where no CFC-free waters can be found at any depth. However, all O-rings of the Niskins were baked before use to remove CFCs; no suspicious variability in samples from the CFC minimum layer was detected. To isolate the samples from lab air, filled syringes were stored in a deep sink that was continuously flushed with uncontaminated surface sea water from the ship's sea water line. Unfortunately, whenever the ship was operating in ice covered waters the sea water pump had to be shut down. During these times the samples were still kept in the same sink filled with sea water. Sample analysis From the syringes, the water samples were injected through a three-way valve into a calibrated glass volume (approximately 35 cc, calibrated to better than 0.1%). The three-way valve and the calibrated volume were flushed with sample water. The water in the calibrated volume was subsequently transferred to a glass stripper chamber where the dissolved gases were purged with ultra high purity Nitrogen. The released CFCs were concentrated by adsorption on a Unibeads cold trap at -60°C. Subsequently the trap was isolated and heated. The desorped gases were backflushed into the chromatographic columns. On system 1, cooling was accomplished by immersing the trap into denatured alcohol cooled by a cryo cooler; heating to 100°C was achieved by immersion in boiling water. System 2 used an automated temperature control: Cooling was done by liquid CO2, heating to 120°C was done electrically. Fig. 3 shows typical chromatograms for samples with intermediate and low concentrations as well as a stripper blank. These chromatograms were obtained from system 2. On both systems, all chromatograms were acquired from the gas chromatograph by a Shimadzu Chromatopac CR601, which also controlled the valves, and on system 2, the automated trap. Through an interface, the chromatograms were then transferred to a PC system where peak integration and data calculation were carried out. Calibration For both systems, the response of the electron capture detector to different amounts of CFCs was calibrated by filling 10 different volumes with standard gas out of an Acculife compressed gas cylinder. After relaxation to ambient temperature and pressure the standard gas was concentrated onto the cold trap and subsequently injected into the columns. One of the standard volumes was used frequently (at least every other hour) to check for drifts in the detector's response. The standard gas (CFCs in Nitrogen) was gravimetrically prepared at Brookhaven National Laboratories and calibrated at L-DEO relative to the SIO 1993 scale. It will be recalibrated as soon as possible after the cruise. Chromatograms from system 2 for different amounts of standard gas as well as a system blank are displayed in Fig. 4. Preliminary results Profiles of CFC11, CFC12 and CFC113 from station 67 are shown in Fig. 5. The intermediate CFC maximum at 250 m corresponds to a local minimum of the potential temperature and is associated with a maximum of the O2 concentration. Fig. 6 shows a vertical section of the CFC11 concentration along 59.6°S from the Kerguelen Plateau into the Australian Antarctic Basin. Surface concentrations are around 6.5 pM/kg along the entire section. In the eastern part of the section above the Kerguelen Plateau, CFC11 concentrations are less than 0.25 pM/kg below 500 m and drop below 0.1 pM/kg approximately 400 m off the bottom. West of station 66, the penetration depth of the CFCs is much larger. The effect is most pronounced at stations 67 to 70, where subpolar waters are encountered. Within the Australian Antarctic Basin, the lowest CFC11 concentrations are around 0.15 pM/kg. Below 4000 m, CFC11 concentrations are higher than 1 pM/kg. The bottom values are around 1.3 pM/kg. CFC intercomparison samples On June 28, 1996, after all samples from the last WOCE station (# 108) were analyzed, a dedicated cast was made to collect water samples for an intercomparison of various European and U.S. CFC laboratories. The rosette was lowered to 1600 m depth where the CFC minimum was located on the previous WOCE stations, and 17 Niskins were closed before the rosette was brought up to the mixed layer. At 35 m depth the remaining 19 Niskins were closed. Back on deck, five samples were drawn in succession from each of 16 deep Niskins. It took at most 15 minutes to draw all samples from each Niskin. The first and last sample were drawn into glass syringes as described above. The analysis results from the first syringe provide the initial CFC concentration of the sample; the measurements from the second syringe give information about possible atmospheric contamination during the sampling interval. A dedicated rig designed by the University of Bremen (PI Wolfgang Roether) and manufactured for L-DEO, was used to draw the other three samples into custom made glass ampoules which were flame-sealed within 15 min after sampling. Four samples each were drawn from 16 of the shallow Niskins. Again, the first sample was drawn into a syringe to establish the CFC concentration of the sampled water mass. The remaining three samples were drawn and sealed into glass ampoules. (One of the deep, and three of the shallow Niskins were not accessible by the ampoule rigs and therefore not sampled at all.) This special cast provided 48 samples each from two different depths sealed in glass ampoules. The initial CFC concentrations were determined from the syringe samples, which were analyzed within ten hours of the completion of the cast. To prevent hydrolysis of CCl4, the ampoules were stored in one of the ships science coolers. They were air-freighted back to Lamont for distribution to the CFC laboratories participating in the intercomparison experiment. C2. Helium, Tritium and 18O Sampling (D. Breger) Helium, tritium and 18O samples were drawn at a total of 606 levels distributed over 34 stations The samples were stored for shipment to Lamont-Doherty Earth Observatory for shore-based extraction and analysis. Helium samples were drawn immediately after CFCs. The helium samplers consisted of one-meter long copper tubes (holding 200 ml of sample) housed in one-meter long aluminum channels, each marked with cruise name, station number, Niskin number, nominal depth, unique sample identification number, and station date. A seawater-cured tygon tube at the intake end delivered the sample from the Niskin bottle and a similar longer tygon tube at the outflow end ensured that no air would fall back into the copper tube during clamping, and directed the outflow away from neighboring samplers. After the intake tygon tube was cleared of air bubbles, the aluminum channel was struck several times while the copper tube was flushed with approximately 250-350 ml of water sample. The outflow end was then clamped with a ratchet wrench, after which the inflow end was clamped. The timing of sampling was logged at several points during the station. After the station, both ends of each channel were dipped in fresh water and towel dried. Fresh water was also sprayed into both ends of each copper tube and shaken out. The channels were immediately placed into their crates for storage and shipment. Tritium samples were collected at the same stations and levels as helium, in one-liter amber glass bottles filled with argon. At the outset of the cruise, all personnel who expected to be in the sampling room during the cruise were warned against wearing tritium-dial watches, and replacement digital watches were issued to those who required them. All bottles were labeled with cruise name, station number, Niskin number, nominal depth, unique sample identification number, and station date. No delivery tube was used, and the bottle was not flushed prior to sample collection, although the caps were rinsed several times with the sample prior to closing. The seawater sample poured directly from the Niskin spigot into the bottle, which was held as upright as possible to avoid argon loss, and as close to the spigot as possible without touching it. The bottles were tightly capped and wiped dry. After each sample was drawn the bottle was returned to its storage/shipping crate. After completion of the station, the caps were sealed with electrical tape to avoid working loose during shipment and the crates sealed and stored for shipment. Samples for 18O analysis were collected at the same stations and levels as helium and tritium in 30 ml clear glass bottles. All bottles were labeled with cruise name, station number, Niskin number, nominal depth, unique sample identification number, and station date. No delivery tube was used. Both the bottles and caps were rinsed several times with the sample prior to collection, which was directly from the Niskin spigot, as close to it as possible without touching. After sampling each bottles was tightly capped and wiped dry and returned to its box. After completion of the station the caps were sealed by electrical tape to avoid working loose during shipment. When each box was full it was returned to its crate, which was sealed and stored for shipment. C3. Radiocarbon Sampling (R. Key) Section S04I is the tenth and final sample collection leg for the WOCE radiocarbon program. Fig. 7 shows the sampling locations. Approximately 60% of the indicated stations were sampled only in the thermocline while the remainder were sampled throughout the water column. Normally 16 samples were collected for thermocline stations and 32 samples for full profiles. Approximately 4500 samples were collected in total. Throughout the Indian Ocean survey, only small volume (AMS) radiocarbon samples were collected. The sample collection procedures described in Joyce (1991) were used. The sample tracking, analysis and quality control procedures outlined in Key (1996) and Key et al. (1996) and described in detail in references cited there, will be used to complete the laboratory phase of this program. Prior to WOCE section S04I, the only radiocarbon data in the Southern Ocean sector of the Indian Ocean were from three GEOSECS stations (430-432). The goals of this leg were to collect a sufficient data set to describe the major features of the area, to identify and characterize any "new" bottom waters and to define the characteristics of the deep and bottom waters which flow north into the deep Indian (and Pacific) Ocean. The extreme lack of data coupled with these goals resulted in a different sampling strategy than used for the rest of the Indian (and Pacific) Ocean. Rather than intersperse 1 full water column sampling with 1-2 thermocline profiles, all stations sampled for radiocarbon were sampled throughout the entire column. Station spacing was nominally 5 degrees of longitude (150nm) with somewhat closer spacing on the two north-south transects toward Antarctica. Thirty-one stations (816 samples) were sampled along section S04I. Upon return to the U.S., these samples will be placed in the analytical queue at NOSAMS (WHOI). Prior to the beginning of the Indian Ocean survey, the advisory group (Key, Quay, Toggweiler & Schlosser) which determines analytical priority decided that the Indian samples would be done on a first-in first-out basis. If this is followed, these samples will be measured in approximately 3-4 years. A second alternative is that these samples will be run along with the S04 Pacific samples. If this is the decision, the samples will be completed in less than 2 years. C4. CO2 Sampling and Analysis (D. Chipman) Sampling Samples for CO2 and alkalinity analyses were drawn from the 10-liter Niskin bottles of the rosette sampler at selected stations Samples for total CO2 (TCO2) analysis were collected in 250 ml glass reagent bottles with ground glass stoppers, sealed with silicone high-vacuum grease and were stored at room temperature prior to analysis. Samples for pCO2 analysis were collected in 500 ml volumetric flasks with plastic-lined screw caps and were stored in the dark at approximately 4°C until analysis. 200 µl of 50%-saturated HgCl2 solution was added to both types of CO2 sample to prevent biological alteration of the CO2 Total CO2 analysis TCO2 analyses were made coulometrically, using the LDEO-design extraction system. This system provides for automated calibration of the coulometer by means of injections of known quantities of pure CO2, whereas sample injection is manual, using glass syringes fitted with special adapters to provide constant sample volumes. A jacketed electrochemical cell with constant-temperature circulator is used to insure the cell solutions are at constant temperature, in order to provide a consistent endpoint pH. The anode and cathode compartments are separated by means of an agar plug in addition to the usual glass frit. Glass wool and a 0.2µ teflon filter are used to prevent aerosols from being carried to the electrochemical cell from the extraction tube, but no chemical clean-up or drying of the carrier gas is used between extraction and analysis. The carrier gas is CO2 -free air, provided by means of a chromatographic-type pure-air generator and Mallcosorb CO2 scrubber. The instrument is calibrated at the beginning and end of the use of a given set of cell solutions, and after every 10-12 sample analyses, using 99.999% CO2. Since this type of calibration verifies the instrumental calibration but does not check the accuracy of the volume of seawater sample being injected, samples of calibrated reference material (CRM) provided by A. Dickson of SIO were run as unknowns at the beginning and end of the use of a given set of cell solutions (immediately after the initial and prior to or after the final instrumental calibration). Each CRM was analyzed using each of the three syringes which were being used for sample injection, so that any change in the volume injected could be detected (none was ever noted). Each set of cell solutions was retired after the instrumental calibration was observed to have changed by 0.10 to 0.15% from the startup value. pCO2 analysis The partial pressure of CO2 at a constant temperature of 4°C was determined using the LDEO gas chromatograph-based analysis system (Chipman et al., 1993). Prior to analysis, samples (525 ml) are brought to temperature in a thermostatted bath and a headspace of approximately 38 ml is created by forcing this much water from the flask with air of known CO2 concentration. The headspace air is recirculated through a gas disperser a few cm below the surface of the water, by means of a small air pump with teflon-covered rubber diaphragm. After approximately 20 minutes of equilibration, a 1 ml aliquot of the equilibrated air is injected into the carrier gas stream of a Shimadzu Mini-2 gas chromatograph by means of a fixed-volume loop on a sampling valve. The hydrogen carrier gas carries the air sample through a chromatographic pre-column and column packed with Chromosorb 102 (0.2 and 2 m), where the various components of the air are separated, and then through a ruthenium catalyst, where the CO2 reacts with the carrier to form methane and water. The methane so produced in quantified by means of a flame ionization detector and a computing integrator to determine the peak areas. Each sample is re-equilibated and analyzed a second time before a second sample is connected and analyzed. After four analyses (two separate samples), the gas chromatogaph is calibrated by means of injection of three air-CO2 mixtures (using the same loop on the injection valve) which are traceable to the WMO calibration scale of C. D. Keeling. All samples are analyzed without the removal of water vapor, and corrections are applied for the perturbation of the TCO2 of the sample due to the equilibration process. The pressure of equilibration is measured just prior to injection by means of a Setra (Model 270) electronic pressure transducer, the output of which is read (as a voltage) by the integrator. The response of the FID is calculated as a second-order polynomial using the values for the calibration gases run immediately before and after each set of unknowns, corrected for drift as a function of time between the calibration periods. C5. Total Alkalinity (E. Peltola) Samples for alkalinity analysis were collected in 500 cm3 glass reagent bottles. Total alkalinity (TA) was determined using a titration system similar to the one used in earlier studies (Millero et al., 1993) and to that developed by Bradshaw and Brewer (1988). The titration system consisted of a Metrohm 665 Dosimat titrator and an Orion 720A pH meter that is controlled by a personal computer. Both the acid titrant in a water-jacketed burette and the seawater sample in a water-jacketed cell were maintained at a constant temperature of 25±0.1°C with a Neslab constant temperature bath. The plexiglas water-jacketed cells used were similar to those used by Bradshaw et al. (1988), but a larger volume (about 200 cm3) was used to increase the precision. This cell had a fill-and-drain valve which increased the reproducibility of the cell volume. A LabWindows C program was used to run the titration, record the volume of the added acid and the emf of the electrodes using RS232 interfaces. The output of the computer program yields values of TA, total CO2 (TCO2), pH, the standard emf (E°) and the pK1 for the dissociation of carbonic acid. The titration is made by adding HCl to seawater past the carbonic acid end-point. A typical titration records the emf reading after it become stable (0.05 mV) and adds enough acid to change the voltage by a pre-assigned increment (10 mV). In contrast to the delivery of a fixed volume increment of acid, this method gives data points in the range of a rapid increase in the emf near the endpoint. A full titration (25 points) takes about 20 minutes. Using two systems a 36-bottle station cast can be completed in 9 hours. The electrodes used to measure the emf of the sample during a titration consisted of a ROSS glass pH electrode and an Orion double junction Ag, AgCl reference electrode. The HCl acid solutions (20 L) used throughout the cruise were made, standardized, and stored in 500 cm3 glass bottles in the laboratory for use at sea. The 0.24790 M HCl solutions were made from 1 M Mallinckrodt standard solutions in 0.45 M NaCl to yield an ionic strength equivalent to that of average seawater (0.7 M). The acid was standardized by Dr. Millero's laboratory using a potentiometric technique and by Dr. Dickson's laboratory by using a coulometric technique (Taylor and Smith, 1959). The volumes of the cells used at sea were determined in the laboratory by weighing the cells filled with degassed Millipore Super Q water. The density of water at the temperature of the measurements (25°C) was calculated from the international equation of state of seawater (Millero and Poisson, 1981). The nominal volumes of all the cells were about 200 cm3 and the values were determined to 0.03 cm3. The volume of HCl delivered to the cell is traditionally assumed to have small uncertainties and equated to the digital output of the titrator. Calibrations of the burettes of the Dosimats with water at 25°C indicate that the systems deliver 3.000 cm3 (the value for a titration of seawater) to a precision of 0.0004 cm3. This uncertainty results in an error of 0.4 µmol kg-1 in TA and TCO2. A number of titrations were made on TCO2 Certified Reference Material (Batch # 31) before, during and after the cruise. Duplicate samples were taken from some Niskin bottles from the surface and from 800 meters for same-cell and between- cell reproducibility at sea. Internal consistency of the cells was checked every day by titrating Certified Reference Material and surface seawater. D. Current meter deployments (T. Whitworth) Nine self-reporting current meters were deployed as part of S04I. The instruments were model 9407 vector-averaging current meters manufactured by Alpha Omega Computer Systems, Inc. of Corvallis, Oregon. The current meter consists of a computer/controller and Argos transmitter in a 17" glass ball enclosed by a plastic hardhat, a rotor and vane assembly, a timed release and anchor, all assembled and packed in a single shipping crate. The meters were preprogrammed at Oregon State University to control data collection, storage, transmission and the releases were preprogrammed to activate on March 15, 1997, the approximate date of the local ice minimum period in the Indian Ocean sector of the Southern Ocean. The only action required for deployment is to confirm that the instrument is operating, that the release is properly programmed, and to select the length of mooring line between the anchor and the current meter. The meters were launched by hand by three people with the assistance of a small crane to lift the anchor over the rail to the water's edge. The current meters were programmed to burst sample in a 10-minute window every hour and to average 24 bursts to provide daily averages of current speed, direction, temperature and pressure. The releases consist of a monofilament line passing through two redundant heating elements that melt the monofilament at the time programmed on the on-board computer. When the current meter surfaces, it reports its data via Argos satellite, repeating the message until the transmitter batteries expire. References Atlas, E. L., Hager, S. W., Gordon, L. I., and Park, P.K., (1971) A Practical Manual for Use of the Technicon Auto-Analyzer(r) in Seawater Nutrient Analyses Revised, Technical Report 215, Reference 71-22, p. 49, Oregon State University, Department of Oceanography. Armstrong, F. A. J., Stearns, C. R., and Strickland, J. D. H., (1967) The measurement of upwelling and subsequent biological processes by means of the Technicon Autoanalyzer and associated equipment, Deep-Sea Research, 14, 381- 389. Bernhardt, H. and Wilhelms, A., (1967) The continuous determination of low level iron, soluble phosphate and total phosphate with the AutoAnalyzer, Technicon Symposia, I, pp. 385-389. Bradshaw, A.L., and P.G. Brewer, 1988, High precision measurements of alkalinity and total carbon dioxide in seawater by potentiometric titration - 1 Presence of unknown protolyte(s)?, Mar. Chem., 23, 69-86. Broecker, W. S. and Takahashi, T., 1966, Calcium carbonate precipitation on the Bahama Banks. Jour. Geophys. Res., 71, 1575-1602. Carpenter, J. H., (1965) The Chesapeake Bay Institute technique for the Winkler dissolved oxygen method, Limnology and Oceanography, 10, 141-143. Carter, D. J. T., (1980) Computerised Version of Echo-sounding Correction Tables (Third Edition), Marine Information and Advisory Service, Institute of Oceanographic Sciences, Wormley, Godalming, Surrey. GU8 5UB. U.K. Chipman, D. W., Mara, J. and Takahashi, T., 1993, Primary productivity at 47oN and 20°W in the North Atlantic Ocean: A comparison between the 14C incubation method and the mixed layer carbon budget. Deep-Sea Res., 40, 151- 169. Culberson, C. H. and Williams, R. T., et al., (1991) A comparison of methods for the determination of dissolved oxygen in seawater, Report WHPO 91-2, WOCE Hydrographic Programme Office. Gordon, L. I., Jennings, J. C., Jr., Ross, A. A., and Krest, J. M., (1992) 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. Hager, S. W., Atlas, E. L., Gordon, L. D., Mantyla, A. W., and Park, P. K., (1972) A comparison at sea of manual and autoanalyzer analyses of phosphate, nitrate, and silicate, Limnology and Oceanography, 17, 931-937. Joyce, T.M., Ed., 1991, WHP operations and methods, WHPO 91-1, WOCE Report No. 68/91. Key, R.M., WOCE Pacific Radiocarbon Program, 1996, Radiocarbon, in press. Key, R.M., P.D. Quay and NOSAMS, 1996, WOCE AMS Radiocarbon I: Pacific Ocean Results: P6, P16 & P17, Radiocarbon, in press. Millard, R. C., Jr., (1982) CTD calibration and data processing techniques at WHOI using the practical salinity scale," Proc. Int. STD Conference and Workshop, p. 19, Mar. Tech. Soc., La Jolla, Ca. Millero, F.J., and A. Poisson, 1981, International one-atmosphere equation of state of seawater, Deep-Sea Res., 28, 625-629. Owens, W. B. and Millard, R. C., Jr., (1985) A new algorithm for CTD oxygen calibration, J. Am. Meteorological Soc., 15, 621. Taylor, J.K., and S.W. Smith, 1959, Precise coulometric titration of acids and bases, J. Res. Natl. Bur. Stds., 63A, 153-159. UNESCO, (1981) Background papers and supporting data on the Practical Salinity Scale, 1978, UNESCO Technical Papers in Marine Science, No. 37, 144. S04I Final Report for AMS 14 C Samples (Robert M. Key) April 19, 1999 1.0 General Information WOCE cruise S04I was carried out aboard the R/V N. B. Palmer in the southern Indian Ocean. The WHPO designation for this cruise was 320696_3. Thomas Whitworth III (TAMU) and James H. Swift (SIO) were the co-chief scientists. The cruise constituted the Indian Ocean portion of WOCE line S4, a meridional circumnavigation of Antarctica at a nominal latitude of 60S. This segment covered the longitudes 20°E to 120°E. A total of 108 full depth CTD/Rosette stations were carried out. The cruise departed Cape Town, South Africa on May 3 and ended at Hobart Tasmania on July 4, 1996. On June 8, science operations were suspended for seven days when the Palmer was diverted to Mirnyy Station in the Davis Sea to deliver emergency food supplies. The reader is referred to cruise documentation provided by the chief scientists as the primary source for cruise information. This report covers details of the small volume radiocarbon samples. The AMS station locations are shown in Figure 1 and summarized in Table 1. A total of 816 D 14 C samples were collected at 31 stations TABLE 1. S04I D 14 C station locations. Bottom Station Month Latitude Longitude Depth (m) ------- ------- -------- --------- --------- 1 5/16/96 -58.008 20.006 5412 7 5/18/96 -61.399 25.749 5243 13 5/20/96 -64.000 30.017 5135 23 5/22/96 -65.134 37.349 4874 26 5/24/96 -64.465 41.619 4435 29 5/25/96 -63.736 46.408 4270 35 5/28/96 -65.456 53.363 501 36 5/28/96 -65.371 53.264 1303 38 5/28/96 -65.104 53.018 2468 40 5/29/96 -64.435 53.072 4200 42 5/29/96 -63.498 53.682 4790 46 5/30/96 -63.501 58.335 4566 51 6/1/96 -62.361 64.406 4365 55 6/3/96 -61.962 70.017 4165 58 6/4/96 -61.806 74.982 4000 62 6/5/96 -61.417 80.489 2480 66 6/6/96 -59.696 84.850 2024 68 6/7/96 -59.660 85.248 4494 70 6/7/96 -59.520 86.221 4304 73 6/14/96 -65.330 91.475 553 76 6/15/96 -64.859 93.004 1808 78 6/16/96 -64.464 92.481 3060 80 6/16/96 -63.653 91.737 3629 84 6/18/96 -63.092 86.007 3809 87 6/20/96 -62.001 90.001 4020 90 6/22/96 -62.286 94.670 3848 93 6/23/96 -62.335 99.558 4316 98 6/24/96 -62.104 105.269 4297 102 6/26/96 -62.244 110.607 3986 105 6/26/96 -62.002 115.331 4255 108 6/27/96 -62.000 120.000 4194 2.0 Personnel 14 C sampling for this cruise was carried out by Robert M. Key (Princeton University). 14 C (and accompanying 13 C) analyses were performed at the National Ocean Sciences AMS Facility (NOSAMS) at Woods Hole Oceanographic Institution. R. Key collected the data from the originators, merged the files, assigned quality control flags to the 14 C and submitted the data files to the WOCE office (4/99). R. Key is P. I. for the 14 C data and NOSAMS for the 13 C data. 3.0 Results This 14 C data set and any changes or additions supersedes any prior release. 3.1 Hydrography Hydrography from this leg has been submitted to the WOCE office by the chief scientist and described in the hydrographic report. 3.2 14C The D 14 C values reported here were originally distributed in a NOSAMS data report (NOSAMS, 1999), February 16, 1999. That reports included results which had not been through the WOCE quality control procedures. This report supersedes that data distribution. All of the AMS samples from this cruise have been measured. Replicate measurements were made on 4 water samples. These replicate analyses are tabulated in Table 2. The table shows the error weighted mean and uncertainty for each set of replicates. Sta-Cast-Bottle D 14 C Err E.W. Mean(a) Uncertainty(b) --------------- -------- ---- ------------ -------------- 51-1-9 -161.31 2.92 -167.40 2.62 -176.84 2.91 51-1-10 -167.33 3.26 -167.40 2.59 -167.51 4.29 58-1-26 -151.72 5.74 -155.78 3.49 -156.65 2.67 70-1-5 -176.29 4.42 -176.06 3.46 -175.69 5.55 --------------------------------------------------------- a. Error weighted mean reported with data set b. Larger of the standard deviation and the error weighted standard deviation of the mean. Table 2: Summary of Replicate Analyses Uncertainty is defined here as the larger of the standard deviation and the error weighted standard deviation of the mean. For these replicates, the simple average of the normal standard deviations for the replicates is 1.0o/oo. This precision estimate is lower than the average error for the time frame over which these samples were measured (Jul. 1996 -Dec. 1998) and lower than the overall mean error for Pacific WOCE samples (Elder, et. al., 1998). Note that the errors given for individual measurements in the final data report (with the exception of the replicates) include only counting errors, and errors due to blanks and backgrounds. The uncertainty obtained for replicate analyses is generally a bet- ter estimate of the true error since it includes errors due to sample collection, sample degassing, etc. Close examination of the data along 67°S in the deep water indicates that 4o/oo is a more realistic of the true error associated with this data set. 4.0 Quality Control Flag Assignment Quality flag values were assigned to all D 14 C measurements using the code defined in Table 0.2 of WHP Office Report WHPO 91-1 Rev. 2 section 4.5.2. (Joyce, et al., 1994). Measurement flags values of 2, 3, and 6 have been assigned. The choice between values 2 (good) and 3 (questionable) involves some interpretation. There is little overlap between this data set and any existing 14 C data, so that type of comparison was difficult. In general the lack of other data for comparison led to a more lenient grading on the 14 C data. When using this data set for scientific application, any 14 C datum which is flagged with a "3" should be carefully considered. When flagging 14 C data, the measurement error was taken into consideration. That is, approximately one-third of the 14 C measurements are expected to deviate from the true value by more than the measurement precision. No measured values have been removed from this data set. Table 3 summarizes the quality control flags assigned to this data set. For a detailed description of the flagging procedure see Key, et al. (1996). Table 3: Summary of Assigned Quality Control Flags Flag Number ---- ------ 2 803 3 6 4 0 5 4 6 3(a) ------------------ (a)Some replicates flagged 3 or 4 5.0 Data Summary Figures 2-6 summarize the D 14 C data collected on this leg. Only D 14 C measurements with a quality flag value of 2 ("good") or 6 ("replicate") are included in each figure. Figure 2 shows the D 14 C values with 2s error bars plotted as a function of pressure. The mid depth D 14 C minimum which normally occurs around 2500 meters in most of the Pacific is absent in this section. In fact, there is very little variation in the deep and bottom water. All of the samples for the entire cruise collected at a depth greater than 1000 meters have a mean D 14 C = -153.8±7.2o/oo with a substantial fraction of this variance due to the samples collected very near the Antarctic slope. This result compares remarkably well with the mean of -156.0±8.5o/oo calculated for the WOCE Pacific Antarctic section (S4P). Figure 3 shows the D 14 C values plotted against silicate. The straight line shown in the figure is the least squares regression relationship derived by Broecker et al. (1995) based on the GEOSECS global data set. According to their analysis, this line (D 14 C = -70 -Si) represents the relationship between naturally occurring radiocarbon and silicate for most of the ocean. They interpret deviations in D 14 C above this line to be due to input of bomb-produced radiocarbon, however, they note that the technique can not be applied at high latitudes as confirmed by this data set. With the exception of the very near surface waters, this region of the Pacific shows no change since GEOSECS which strongly implies that the data in Figure 3 indicates a failure of the technique in this area rather than bomb-produced contamination throughout the water column. Figure 4 shows all of the S04I radiocarbon values plotted against potential alkalinity normalized to a salinity of 35 (defined as [alkalinity + nitrate]* 35/ salinity). The straight line is the regression fit (14 C = -68 -(PALK_ 35 -2320) derived by S. Rubin (LDEO) to all of the GEOSECS results for waters which were assumed to have no bomb-produced 14 C (depths greater than 1000 meters, but including high latitude samples). Preliminary investigation indicates that this new method for separating bomb-produced and natural 14 C works in high latitude waters. For this data set it appears that the regression intercept derived from the GEOSECS data may be a bit too low. Regardless, if the function is valid, then for these data, waters which have alkalinity values less than ~2400 mmole/ kg have a significant amount of bomb-produced radiocarbon. If this is true, and if the values have changed little since GEOSECS, then most of the bomb contamination had to have been distributed throughout most of the water column even as early as the mid 1970's. Figures 5-7 show gridded sections of the D 14 C data. The data were gridded using the "loess" methods described in Chambers et al. (1983), Chambers and Hastie (1991), Cleveland (1979) and Cleveland and Devlin (1988). Figure 5 shows the main zonal cruise section along ~62°S. The colors in the image indicate D 14 C while the contours are CFC-11 concentration (pmol/kg; preliminary data from Bill Smethie (LDEO) and Mark Warner (UW)). Significant resolution is lost in the deep water D 14 C since most of the variability is near the surface. Nevertheless, a strong correlation in the two distributions is immediately apparent. The bottom waters both east and west of the Kerguelen Ridge (~ 80°E) have appreciable chlorofluorocarbon concentrations and are most likely contaminated with bomb-produced radiocarbon. The highest near bottom (pressure >3750dB) D 14 C values along this section range between -140o/oo and -130o/oo and are comparable to near bottom waters at similar latitudes in the Pacific (Key and Schlosser, 1999). Figure 6 and Figure 7 show contoured sections of the D 14 C distribution along 65°E and 90°E respectively. Note that the contour interval used in the two figures is different. The 65°E and 90°E sections clearly show penetration of bomb radiocarbon along the Antarctic continental slope. 6.0 References and Supporting Documentation Broecker, W. S., S. Sutherland and W. Smethie, Oceanic radiocarbon: Separation of the natural and bomb components, Global Biogeochemical Cycles, 9(2), 263-288, 1995. Chambers, J. M. and Hastie, T. J., 1991, Statistical Models in S, Wadsworth & Brooks, Cole Computer Science Series, Pacific Grove, CA, 608pp. Chambers, J. M., Cleveland, W. S., Kleiner, B., and Tukey, P. A., 1983, Graphical Methods for Data Analysis, Wadsworth, Belmont, CA. Cleveland, W. S., 1979, Robust locally weighted regression and smoothing scatterplots, J. Amer. Statistical Assoc., 74, 829-836. Cleveland, W. S. and S. J. Devlin, 1988, Locally-weighted regression: An approach to regression analysis by local fitting, J. Am. Statist. Assoc, 83: 596-610. Elder, K. L. A. P. McNichol and A. R. Gagnon, Reproducibility of seawater, inorganic and organic carbon 14 C results at NOSAMS, Radiocarbon, 40(1), 223-230, 1998 Joyce, T., and Corry, C., eds., Corry, C., Dessier, A., Dickson, A., Joyce, T., Kenny, M., Key, R., Legler, D., Millard, R., Onken, R., Saunders, P., Stalcup, M., contrib., Requirements for WOCE Hydrographic Programme Data Reporting, WHPO Pub. 90-1 Rev. 2, 145pp., 1994. Key, R. M., WOCE Pacific Ocean radiocarbon program, Radiocarbon, 38(3), 415- 423, 1996. Key, R. M., P. D. Quay, G. A. Jones, A. P. McNichol, K. F. Von Reden and R. J. Schneider, WOCE AMS Radiocarbon I: Pacific Ocean results; P6, P16 & P17, Radiocarbon, 38(3), 425-518, 1996. Key, R. M. and P. Schlosser, S4P: Final report for AMS 14 C samples, Ocean Tracer Lab Technical Report 99-1, January, 1999, 11pp. NOSAMS, National Ocean Sciences AMS Facility Data Report #99-043, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, 2/16/1999. Figure Legends Figure 1: AMS 14 C station map for WOCE S04I. Figure 2: D 14 C results for S04I stations shown with 2s error bars. Only those measurements having a quality control flag value of 2 or 6 are plotted. Figure 3: D 14 C as a function of silicate for S04I AMS samples. The straight line shows the relationship proposed by Broecker, et al., 1995 (D 14 C = -70 -Si with radiocarbon in o/oo and silicate in mmol/kg). Two-sigma error bars are given for the D 14 C measurements. Figure 4: Based on the new method devised by S. Rubin, the samples which plot above the line and have potential alkalinity values less than about 2400 mmole/kg are contaminated with bomb-produced 14 C.. Figure 5: D 14 C concentrations, along main east-west section of S04I at approximately 62°S, are indicated by color. Contour lines are preliminary CFC-11 concentrations (pmol/kg). Figure 6: D 14 C along ~65°E near the Antarctic slope. The near bottom values along the lower slope indicate entrainment of "new" bottom water. Figure 7: D 14 C along ~90°E near the Antarctic slope. The near bottom values along the lower slope indicate entrainment of "new" bottom water. WHPO-SIO DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 01/23/98 Rutz BTL/CTD Data are NonPublic 01/23/98 Whitworth SUM/BTL Submitted 07/29/98 Johnson DOC S04I is next on ODF CTD report agenda 05/05/99 Swift Cruise ID Confirming Whitworth as Chi. Sci. Regarding S4I, Nowlin had foot surgery shortly before the cruise and cancelled. All my interactions since have been with Tom Whitworth. So, yes, he is Chief Scientist and chief contact for the R/V Palmer S4I cruise. Jim 03/24/00 Schlosser He/Tr Data are Public As mentioned in my recent message, we will release our data with a flag that indicates that they are not yet final. We started the process of transferring the data and we will continue with the transfer during the next weeks. I had listed the expected order of delivery in my last message. 05/05/00 Key DELC14 Data are NonPublic Thank you for the notice regarding S4I C14 and the new CD-ROM. The proprietary period for this data (2 years after measurement) ends 2/16/2001 or later (I'm not sure that the measurements for this cruise are even finished). I do not want these data made public yet. 05/09/00 Whitworth CTD/BTL Data are Public The 1996 Palmer S4I data may be made public. I am almost certain that my co-Chief Scientist will agree. 06/08/00 Bartolacci CTD/BTL/CFCs Website Updated data unencrypted 09/13/00 Kozyr CO2 Final Data Submitted TCARBN, ALKALI, PCO2, PCO2TMP I have just put the final and public CO2-related data for the WOCE Section S4I (EXPOCODE 320696_2) in your INCOMING ftp area. The data consist of TCARBN, ALKALI, PCO2, PCO2TMP, and quality flags. The data were submitted to CDIAC by Taro Takahashi of LDEO and Frank Millero of RSMAS. Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 06/20/01 Johnson CTD Data Update; Processing error corrected revised data available by ftp ODF has discovered a small error in the algorithm used to convert ITS90 temperature calibration data to IPTS68. This error affects reported Mark III CTD temperature data for most cruises that occurred in 1992-1999. A complete list of affected data sets appears below. ODF temperature calibrations are reported on the ITS90 temperature scale. ODF internally maintains these calibrations for CTD data processing on the IPTS68 scale. The error involved converting ITS90 calibrations to IPTS68. The amount of error is close to linear with temperature: approximately -0.00024 degC/degC, with a -0.00036 degC offset at 0 degC. Previously reported data were low by 0.00756 degC at 30 degC, decreasing to 0.00036 degC low at 0 degC. Data reported as ITS90 were also affected by a similar amount. CTD conductivity calibrations have been recalculated to account for the temperature change. Reported CTD salinity and oxygen data were not significantly affected. Revised final data sets have been prepared and will be available soon from ODF (ftp://odf.ucsd.edu/pub/HydroData). The data will eventually be updated on the whpo.ucsd.edu website as well. IPTS68 temperatures are reported for PCM11 and Antarktis X/5, as originally submitted to their chief scientists. ITS90 temperatures are reported for all other cruises. Changes in the final data vs. previous release (other than temperature and negligible differences in salinity/oxygen): S04P: 694/03 CTD data were not reported, but CTD values were reported with the bottle data. No conductivity correction was applied to these values in the original .sea file. This release uses the same conductivity correction as the two nearest casts to correct salinity. AO94: Eight CTD casts were fit for ctdoxy (previously uncalibrated) and resubmitted to the P.I. since the original release. The WHP- format bottle file was not regenerated. The CTDOXY for the following stations should be significantly different than the original .sea file values: 009/01 013/02 017/01 018/01 026/04 033/01 036/01 036/02 I09N: The 243/01 original CTD data file was not rewritten after updating the ctdoxy fit. This release uses the correct ctdoxy data for the .ctd file. The original .sea file was written after the update occurred, so the ctdoxy values reported with bottle data should be minimally different. ====================================================================== DATA SETS AFFECTED: WOCE Final Data - NEW RELEASE AVAILABLE: WOCE Section ID P.I. Cruise Dates ------------------------------------------------------------ S04P (Koshlyakov/Richman) Feb.-Apr. 1992 P14C (Roemmich) Sept. 1992 PCM11 (Rudnick) Sept. 1992 P16A/P17A (JUNO1) (Reid) Oct.-Nov. 1992 P17E/P19S (JUNO2) (Swift) Dec. 1992 - Jan. 1993 P19C (Talley) Feb.-Apr. 1993 P17N (Musgrave) May-June 1993 P14N (Roden) July-Aug. 1993 P31 (Roemmich) Jan.-Feb. 1994 A15/AR15 (Smethie) Apr.-May 1994 I09N (Gordon) Jan.-Mar. 1995 I08N/I05E (Talley) Mar.-Apr. 1995 I03 (Nowlin) Apr.-June 1995 I04/I05W/I07C (Toole) June-July 1995 I07N (Olson) July-Aug. 1995 I10 (Bray/Sprintall) Nov. 1995 ICM03 (Whitworth) Jan.-Feb. 1997 non-WOCE Final Data - NEW RELEASE AVAILABLE: Cruise Name P.I. Cruise Dates ------------------------------------------------------------ Antarktis X/5 (Peterson) Aug.-Sept. 1992 Arctic Ocean 94 (Swift) July-Sept. 1994 Preliminary Data - WILL BE CORRECTED FOR FINAL RELEASE ONLY NOT YET AVAILABLE: Cruise Name P.I. Cruise Dates ------------------------------------------------------------ WOCE-S04I (Whitworth) May-July 1996 Arctic Ocean 97 (Swift) Sept.-Oct. 1997 HNRO7 (Talley) June-July 1999 KH36 (Talley) July-Sept. 1999 "Final" Data from cruise dates prior to 1992, or cruises which did not use NBIS CTDs, are NOT AFFECTED. post-1991 Preliminary Data NOT AFFECTED: Cruise Name P.I. Cruise Dates ------------------------------------------------------------ Arctic Ocean 96 (Swift) July-Sept. 1996 WOCE-A24 (ACCE) (Talley) May-July 1997 XP99 (Talley) Aug.-Sept. 1999 KH38 (Talley) Feb.-Mar. 2000 XP00 (Talley) June-July 2000 Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 09/13/00 Kozyr CO2 Final Data submitted I have just put thefinal and public CO2-related data for the WOCE Section S4I (EXPOCODE 320696_2) in your INCOMING ftp area. The data consist of TCARBN, ALKALI, PCO2, PCO2TMP, and quality flags. The data were submitted to CDIAC by Taro Takahashi of LDEO and Frank Millero of RSMAS. 12/11/00 Uribe DOC Submitted 2000.12.11 KJU File contained here is a CRUISE SUMMARY and NOT sumfile. Documentation is online. 2000.10.11 KJU Files were found in incoming directory under whp_reports. This directory was zipped, files were separated and placed under proper cruise. All of them are sum files. Received 1997 August 15th. 06/21/01 Uribe CTD/BTL Website Updated; EXCHANGE File put online 10/02/01 Diggs SUM Data Update; SUM file format corrected At Mary Johnson's request I have corrected line 23-24 (Cast 1, Station 1 EN) which needed a formatting correction. That line needed a line feed and an expocode. Old file moved to original and all documentation updated. 10/12/01 Key DELC14, DELC13 Submitted; reformatting needed To save time the S4I file is attached. I included c13 as well as c14. Note that my software isn't aware of the "official" number of decimal places. If too many are listed the values can be rounded, if too few just add the appropriate number of "0"'s. 12/11/01 Key DELC14 DQE Report Submitted to WHPO 12/26/01 Uribe CTD Website Updated; EXCHANGE File Added CTD has been converted to exchange using the new code and put online. 01/03/02 Hajrasuliha CTD Internal DQE completed created .ps files. created *check.txt files. Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 04/01/02 Buck DELC13 Data moved from incoming Moved data from /usr/export/html- public/cgi/SUBMIT/INCOMING/20020401.102545_GERLACH_SO4I to /usr/export/html- public/data/onetime/southern/s04/s04i/original/20020401.102545_GER LACH_SO4I. Directory contains a readme file from the data submission page and a data file with delc13. 04/12/02 Buck C14 Data moved from incoming; Header added Moved S4I.C14 data from /usr/export/ftp-incoming to s04/s04i/original/20020410_KEY_S4I_C14. Data is a EXCHANGE file and contains C14 data. Added this line to header # S04I, 320696_3, Key 05/08/02 Anderson C14/C13/CO2/He Data merged into online file Merged DELC13, TCARBN, ALKALI, DELC14, C14ERR, PC02, HELIUM, DELHE3, and DELHER into the .sea file and put online. Merged DELC14 and C14ERR from S4I.C14 found in web site: ...southern/s04/s04i/original/20002010_KEY_S4I_C14 into the online file. Merged DELC13 from 20020401.102545_GERLACH_S04I_whpo_s04i.txt found in web site: ...southern/s04/s04i/original/20020401.102545_GERLACH_S04I into the online file. Merged TCARBN, ALKALI, and PCO2 from s4icarb.txt found in web site: ...southern/s04/s04i/original/2000.09.13_S4I_CARB_BARTOLACCI into the online file. NOTE: Except for the above merged data the designation for missing values is -9 there is no decimal or decimal places. Merged HELIUM, DELHE3, and DELHER. Received data from Bob Newton on April 30, 2002.file in: .../southern/s04/s04i/20020430_S04I_HELIUM_BNEWTON Some of the DELHE3 values are very strange ie 9367.3822, but they are flagged as 4. There was no tritium in this file. 05/09/02 Anderson DELHE3 Update Needed; Some values out of range Bob, I have been merging the helium data you sent in April and have a question. In some cases the delhe3 values are very out of line with the rest of the data. Granted they are flagged 4, but since they exceed in both directions the range listed in the WOCE manual, our programs choke on them. What should we do with these samples (see sta. 2, samp. 34, 25, 24, 22, and 20)? Also, occasionally (see sta. 40, samp. 7) there is a delher value when there is no delhe3 value. What should be done with these? Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 05/09/02 Newton DELHE3 Answer to Sarilee's query These far-out-of-range values are typically from samples where something has gone drastically wrong in the extraction process (loss of vacuum, cracked ampule, etc.). I've reported them as "4" rather than "5" just in case you guys wanted to keep track of where samples were taken; and where they were not. But since, for reasons such as those cited above, we were not able to make a legitimate measurement I don't see any problem in changing their status to "5" (no value reported) and changing the measurement values to "-999". Peter: does that seem right to you? Where there is no delhe3 value reported, the delhe3_err value should be "-999". 05/09/02 Anderson DELHE3/DELHER Website Updated Reformatted data online, new exchange file online. Made some changes to the DELHE3 and DELHER re Bob Newton's response to my e-mail. Made new exchange file. 12/10/02 Kappa DOC cruise report updated Added: Discussion and table of ALACE deployments Discussion and table of current meter deployments Section on underway measurements including Navigation and Bathymetry Meteorological Observations Adcp Atmospheric Chemistry CO2 Analysis CFC Analysis Thermosalinograph and underway pCO2 Underway pCO2 Hydrographic Measurements including Water Sampling Package (Rosette and CTD) CTD Measurements CTD Data Processing Bottle Measurements Bottle Data Processing Salinity Analysis Oxygen Analysis Nutrient Analysis Chlorofluorocarbon Analysis Sample collection Sample analysis Calibration Preliminary results CFC intercomparison samples Helium, Tritium and 18O Sampling Radiocarbon Sampling CO2 Sampling and Analysis Sampling Total CO2 analysis pCO2 analysis Total Alkalinity Current meter deployments References Final Report for S04I AMS 14C Samples These Data Processing Notes Date Contact Data Type Data Status Summary -------- ----------- -------------- ------------------------------------ 02/11/03 Diggs He/Tr Data Ready to be Merged (Same as A24 he/tr data) Data files (xls and csv) were sent to ODF email account. Once found, these data were place in the holding directory under 20020522_S04I_HE-TR_NEWTON and are ready to merge into the bottle file. 03/12/03 Muus DELC13 Data online corrected Decimal-1 data replaced with decimal-2 data Replaced DELC13 decimal- 1-data with decimal-2-data from same original data files. Notes on S04I Mar 12, 2003 D. Muus 1. Replaced 1-decimal-place DELC13 in s04ihy.txt (20020509WHPOSIOSA) with 2-decimal-place DELC13 from: /usr/export/html-public/data/onetime/southern/s04/s04i/original 20020401.102545_GERLACH_SO4I/20020401.102545_GERLACH_SO4I_whpo _so4i.txt 2. Both QUALT1 and QUALT2 set to QF value given in original data file. 3. Replaced all "1"s in QUALT2 with QUALT1 flags. Checked that non-1 values in QUALT2 are equal to the corresponding QUALT1 flags in the original bottle file. Only dicrepancy was Station 2, Cast 2, Sample 24 where original DELHE3 QUALT1 flag was 5 whereas original QUALT2 flag was 9. Changed new bottle file to correspond with with original. 4. Made new exchange file for Bottle data. 5. Checked new bottle file with Java Ocean Atlas. 08/28/03 Anderson CTD/BTL/SUM Final Data Submitted, online Merged final data files into online hyd file S04I event log by Sarilee Anderson (132.239.114.244/xebec.ucsd.edu) Expocode: 320696_3 SUM, CTD, Bottle: (ctdprs, ctdtmp, ctdsal, ctdoxy, theta, salnty, oxygen, silcat, nitrat, nitrit, phspht, cfc-11, cfc-12, helium, delhe3, delc14, delc13, tcarbn, alkali, pco2, delher, c14err, qualt1, qualt2) ODF submitted final data files for the bottle, ctd, and .sum data. I merged values and QUALT flags from the online file into the new final bottle file. Made new exchange and netcdf files. Put all files online and sent notes to Jerry. Notes on the s04i remerge: Aug. 27, 2003 Copied the QUALT1 flags to the QUALT2 flags in the ODF final data file 320696_3.sea found in s04/s04i/original/ODF_FINAL_2003_S04I/s4ihyd. Merged CFC-11, CFC-12, HELIUMN, DELHE3, DELHER, DELC14, 14ERR, DELC13, TACRBN, ALKALI, and PCO2 and their corresponding QUALT1 and QUALT2 flags from the online file 20030312WHPOSIODM into the ODF final data file 320696_3.sea. I did not merge REVPRS and REVTMP because the values were all -9.0. Checked the .sum file and made some minor column adjustments. The ctd files (s4ictd.zip) found in the ODF_FINAL_2003_S04I directory were formatted correctly, renamed them from 00101.ctd to s04i0001.wct, ect., and made a new zip file, s04ict.zip. 09/02/03 Kappa DOC Cruise Documentation Updated Added ODF "Final Cruise Report" Expanded these Data Processing Notes 09/09/03 Coartney CrsRpt New PDF and text docs online 04/28/06 Kozyr CrsRpt OK to add to online cruise report Actually it is a very good idea to include CDIAC NDPs (Numeric Data Packages) that describe methods and instrumentation of CO2-related measurements with the related data files in WHPO/CCHDO database. I would be happy to see that. 11/02/06 Swift CFCs remerge Warner's DQE'd CFCs It was decided at today's CCHDO meeting to merge or remerge CFCs for all WHP cruises in Mark Warner's CFC DQE file (Southern Ocean WHO lines). This will assure all that the CFCs for these cruises are indeed updated as intended. Danie and Sarilee will attend to this promptly. Danie will see that the sections of greatest urgency to Lynne receive top priority. The list of cruises in Mark's file was as follows: A21: EXPOCODE: 06MT11_5 A23: EXPOCODE: 74JC10_1 I06S: EXPOCODE: 35MFCIVA_1 MARGINEX: EXPOCODE: 09AR9604_1 S03_S04I: EXPOCODE: 09AR9404_1 S04A: EXPOCODE: 06AQANTIII_4 S04I: EXPOCODE: 320696_3 S04P: EXPOCODE: 90KDIOFFE6_1 SR04A_A12: EXPOCODE: 06AQANTX_4 SR04_ANTXV4: EXPOCODE: 06ANT15_4 It may be that the CFCs for the following cruises from the list above have already been updated: > sr04antxv4 > s04p > a23 > a21 But, to be certain, the CCHDO will update them as well. As far as why these cruises did not get updated with Mark's DQE'd CFCs, we have no idea. Sorry. All of the other ocean basins' CFCs were updated years ago. 07/24/13 Kappa CrsRpt Updated pdf and text versions online • Chief Scientist changed from James Swift to Thomas Witworth on web site, as per James Swift • Note added to table 1: "The LADCP was lost during a test, therefore no LADCP data are reported for this cruise." • Data Processing notes updated/expanded • New test and pdf versions of the cruise report added to online website • Old cruise reports moved to "original" directory.