Cruise Report: Japan/East Sea hydrography, summer 1999, Revelle cruise


Table of contents

A. Cruise narrative
A.1. Highlights: Expedition; Chief Scientist; Ship; Ports of Call; Cruise dates
A.2. Cruise summary
A.3. Narrative
A.4. Interlaboratory comparisons of chemistry methods
A.5. List of principal investigators
A.6. Cruise participants
B. Description of measurement techniques and calibration
B.1. CTD (conductivity-temperature-depth): Carl Mattson (SIO/ODF)
B.2. Salinity analyses: Carl Mattson (SIO/ODF)
B.3. Oxygen water sample analyses: Carl Mattson and Ron Patrick
B.4. Nutrient analyses: Carl Mattson and Doug Masten (SIO/ODF)
B.5. Chlorofluorocarbon measurements: Mark Warner and DongHa Min (UW)
B.6. Alkalinity and pH: Dong-Jin Kand (SNU) and Pavel Tischenko (POI)
B.7. Noble Gas and Tritium Sampling: Clare Postlethwaite (IOS)
B.8. Oxygen Isotope Sampling: Clare Postlethwaite (IOS)
B.9. Other SNU sampling (helium, tritium, D-14, Del 18O, SF6): Dong-Jin Kang (SNU)
B.10. Underway pCO2 measurements: Dong-Jin Kang, Doshik Hahm (SNU)
B.10.a. pCO2 measurements.
B.10.b. Thermosalinograph measurements.
B.10.c. Underway chlorophyll sampling.
B.11. Acoustic doppler current profiling (ADCP): Lynne Talley (SIO)
B.11.a. Lowered ADCP.
B.11.b. Underway ADCP.
B.12. Meteorology: R/V Revelle (Talley; SIO)
B.13. Navigation: R/V Revelle (Talley; SIO)
B.14. Bathymetry: R/V Revelle (Talley; SIO)
B.15. Video Plankton Recorder (VPR): Carin Ashjian and Cabell Davis (WHOI)
B.16. Plankton net tows: Carin Ashjian and Cabell Davis (WHOI)
B.17. Bio-optical studies: Greg Mitchell (SIO)
C. Distribution of data and samples to groups other than originating principal investigators


A. Cruise narrative

A.1. Highlights

a. Expedition
HNRO7 (Expedition Hahnaro Leg 7)

b. Chief Scientist
Lynne D. Talley
Scripps Institution of Oceanography 0230
La Jolla, CA 92093-0230 USA
ltalley@ucsd.edu

c. Ship
R/V Revelle, Captain David Murline

d. Ports of Call
Pusan, Korea

e. Cruise dates
24 June 1999 - 17 July 1999

A.2. Cruise summary

a. Cruise track (Fig. A.1)
List of events, from ship's officers, with all station (CTD, optical, net tow) and VPR towing times.
CTD station locations and times in WOCE Hydrographic Programme format.

Digital pictures, courtesy of Andy Girard.

b. Station sampling
113 CTD/24-bottle rosette stations; 112 stations included LADCP
(2156 bottles tripped)
Water sampling to the bottom for temperature, salinity, oxygen, nitrate, phosphate, silicate, nitrite, CFC's, pH, alkalinity, C14, del18O, helium, tritium, argon, neon. Surface sampling at selected station locations for delta-C13, phytoplankton growth rates and calcite. Average depth of cast: 2500 m.
37 Bio-optical casts
15 Net tows near the surface

c. Underway sampling

towed VPR (Video Plankton Recorder), with planktonic taxonomic type and abundance, temperature, conductivity, fluorescence, light attenuation and PAR yoyoing to 80 meters depth every 7 km between CTD stations.
pCO2
surface temperature and salinity
Seabeam center beam bathymetry
Knudsen echo sounder bathymetry
ADCP (Acoustic Doppler Current Profiling)
meteorology

d. Floats and drifters
2 Minimet surface drifters
2 Profiling ALACE floats ballasted to 800 meters

A.3. Narrative

The R/V Revelle departed Pusan, Korea on June 24, 1999 at 1600 in good weather and returned on July 17. This was the seventh leg of the Hahnaro (HNRO) expedition. Generally calm to moderate seas throughout the cruise. Air temperature was in the 16-22 C range. There was occasional rain. Three separate sampling programs were aboard: CTD/rosette/chemistry, bio-optics, and VPR (Video Plankton Recorder). The cruise leg covered the Korean and Japanese sectors of the Japan/East Sea. The purposes of the cruise leg were to map the water properties and geostrophic circulation of the Japan/East Sea from top to bottom, the bio-optical properties, and the plankton distribution. The water properties and circulation of the Russian sector are to be measured in a companion cruise on the Khromov, following the Revelle leg.

CTD/rosette station sampling was to the bottom at each of the 112 stations. Most stations were separated by 10 to 30 nautical miles. The station pattern covered most of the southern and eastern Japan/East Sea. One station near Dok Do was abandoned because the local Korean patrol was not aware of our clearance to work. One extra station (113) to 800 m was made on the return to Pusan in order to test the CTD which will be the backup CTD on the Khromov. On most stations, 24 samples were collected from top to bottom. Maximum bottle spacing in the deeper was 250 meters with some exceptions. Most sampling in the upper waters was based on the many features in the CTD salinity and oxygen and the transmissometer. An altimeter on the CTD/rosette frame was used for the bottom approach on most stations. A pinger on the CTD/rosette frame was used for several stations. A lowered acoustic doppler current profiler was used on every station.

The VPR was towed between most station pairs except for the longer steams between sections. On most days two separate casts for bio-optics were made. At these stations, extra samples for bio-optical properties were often collected from near-surface rosette bottles from the CTD cast.

A plankton net tow was done at 15 stations.

A.4. Interlaboratory comparisons of chemistry methods

Alkalinity and pH: A comparison of alkalinity and pH methods between the Seoul National University group under Kyung-Ryul Kim (Dong-Jin Kang aboard the Revelle) and the Pacific Oceanological Institute group under Pavel Tishchenko was carried out during the cruise. POI sampling for pH and alkalinity was at every station. SNU sampling was at 15 stations for comparison of methods. The results of the comparison are included in section B.6.c.

CFC: Samples for CFCs were collected in glass ampoules for analysis at the UW laboratory and comparison with analyses carried out on the Revelle. All CFC sampling on the Khromov will be using these glass ampoules.

A.5. List of principal investigators

  1. Lynne Talley: Temperature, salinity, oxygen, nutrients (CTD and rosette): SIO/UCSD
  2. Lynne Talley and Peter Hacker: Lowered Acoustic Doppler Current Profiling: SIO/UCSD and U. Hawaii
  3. Lynne Talley: Shipmounted Acoustic Doppler Current Profiling: SIO/UCSD
  4. Steve Riser: Subsurface PALACE floats: U. Washington
  5. Dong-Kyu Lee and Peter Niiler: Minimet surface drifters: Pusan University and SIO/UCSD
  6. Pavel Tischenko: Alkalinity, pH: POI
  7. Kyung-Ryul Kim: Alkalinity, pH: SNU
  8. Kyung-Ryul Kim: Carbon 14: SNU
  9. Kyung-Ryul Kim: Delta 18O: SNU
  10. William Jenkins: Delta 18O: IOS
  11. Mark Warner: Chlorofluorocarbons: U. Washington
  12. William Jenkins: Helium-3, tritium, neon, argon, krypton: IOS
  13. Kyung-Ryul Kim: Surface pCO2, T, S, chlorophyll, (pN2O): SNU
  14. Clive Dorman and Robert Beardsley: Shipbased meteorological measurements (WHOI ASIMET): SIO/UCSD and WHOI
  15. Greg Mitchell: Bio-optical profiles: SIO/UCSD
  16. Greg Mitchell: Water particle size, absorption, pigments: SIO/UCSD
  17. Carin Ashjian and Cabell Davis: Towed video plankton recorder and temperature/salinity: WHOI
  18. Carin Ashjian and Cabell Davis: Plankton net tows: WHOI

A.6. Cruise participants

  1. Lynne Talley (SIO) - Chief scientist - ltalley@ucsd.edu
  2. David Newton (SIO) - Programmer, LADCP, deck watch - dnewton@ucsd.edu
  3. Carl Mattson (SIO/ODF) - ODF Tech-in-Charge/Electronics/Deck watch - cmattson@ucsd.edu
  4. Doug Masten (SIO/ODF) - Nutrient analyst/data processing - dmasten@ucsd.edu
  5. Ron Patrick (SIO/ODF) - Oxygen/Bottle data - rpatrick@ucsd.edu
  6. Alexander Nedashkovskiy (POI) - Nutrients
  7. Sergey Sagalaev (POI) - Oxygen
  8. Joe Martin (SIO) - Salinity, deck watch, underway ADCP - jmartin@ucsd.edu
  9. Michael Gorelkin (FERHRI) - Salinity
  10. Igor Titov (FERHRI) - Electronics, Deck watch
  11. Vladimir Luchin (FERHRI) - CTD/rosette operations, CTD console - hydromet@online.ru
  12. Nikolay Rykov (FERHRI) - CTD/rosette operations
  13. Vladimir Kraynev (FERHRI) - CTD/rosette operations
  14. Igor Zhabin (POI) - CTD/hydrographic data management, software, processing,deck
  15. Vladimir Ponamarev (POI)- CTD/hydrographic data management, software, processing
  16. Pavel Tischenko (POI) - POI chemistry head, CO2 (pH by EMF)
  17. Ruslan Chichkin (POI) - CO2 (pH by EMF)
  18. Dong-Jin Kang (SNU) - underway chemistry, CO2 (pH by spectro.)
  19. Doshik Hahm (SNU) - CO2 (pH by spectro.)
  20. Elena Ilyina (POI) - CO2 (Alkalinity)
  21. Maria Shvetsova (POI) - CO2 (Alkalinity)
  22. Mark Warner (U. Washington) - CFC
  23. DongHa Min (SIO) - CFC
  24. Clare Postlethwaite (IOS, Southampton) - helium, tritium, neon, argon
  25. Carin Ashjian (WHOI) - VPR
  26. Cabell Davis (WHOI) - VPR
  27. Larry Costello (WHOI) - VPR
  28. Philip Alatalo (WHOI) - VPR
  29. Andrew Girard (WHOI) - VPR
  30. Gregory McGrath (WHOI) - VPR
  31. Greg Mitchell (SIO) - Bio-optics
  32. John Wieland (SIO) - Bio-optics
  33. Sergei Zakharkov (POI) - Bio-optics
  34. Jeong-Eon Moon (KORDI) - Bio-optics
  35. Dan Jacobson (SIO) - Revelle computer technician
  36. Tammy Koonce (SIO) - Revelle resident marine technician, Deck Watch
Institution acronyms
  1. FERHRHI - Far-Eastern Regional Hydrometeorological Research Institute, Vladivostok, Russia
  2. KORDI - Korea Ocean Research and Development Institute, Seoul, Korea
  3. POI - Pacific Oceanological Institute, Far Eastern Branch Russian Academy of Sciences, Vladivostok, Russia
  4. SIO - Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA USA
  5. SIO/ODF - SIO Oceanographic Data Facility
  6. SNU - Seoul National University, Seoul, Republic of Korea
  7. UW - University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195 USA
  8. WHOI - Woods Hole Oceanographic Institution, Woods Hole, MA USA

B. Description of measurement techniques and calibration

B.1. CTD (conductivity-temperature-depth): Carl Mattson (SIO/ODF)

CTD data were recorded on IBM PC's. Digital backups were made on CDROMS and Zip disks. Analog backups were made on VCR cassettes.

CTD fish numbers used:
NBIS Model MKIII ODF CTD#3 stations 1-8,113
NBIS Model MKIII ODF CTD#5 stations 9-112

The rosette consisted of:

NBIS MKIIIB CTD s/n 01-1095 (ODF ctd#3) sta 1-8, 113
NBIS MKIIIB CTD s/n 01-1070 (ODF ctd#5) sta 9-112
Sensormedics Oxygen Sensor s/n 6-12-07 sta 1-108
Sensormedics Oxygen Sensor s/n 6-12-08 sta 109
Sensormedics Oxygen Sensor s/n 6-02-08 sta 110-113
FSI OTM s/n 1322 sta 113
STS 24 bottle rosette frame
24pl Seabird pylon model SBE32 s/n 3212613-0164
Seabird Temperature Sensor SBE35 s/n 3516590-0011
SIO made Bullister style 10 liter bottles
Benthos Pinger model 2216 s/n 1275
Simrad Altimeter model 807 s/n 0711090
STS Battery Pack for Altimeter
RDI LADCP CS-150KHZ s/n 1546
LADCP Battery Pack
Wetlabs Cstar 25cm transmissometer c/n CST-244DB
Wetlabs Cstar 25cm transmissometer c/n CST-245DB
Comments:

CTD#3:

Conductivity sensor failed during Sta 9 cast 1.
Ctd#3 was replaced by CTD#5 prior to sta 9 cast 2.
FSI OTM #1322 was the second temp sensor on sta 113
The conductivity sensor drifted again on sta 113.
CTD#5:
CTD #5 has dual sensors mounted on twin turrets - two identical Temperature channels and two identical conductivity channels. CTD sensors soaked in distilled water between all casts.
Swapped sensor pair in config file starting sta 59.
PRT#2 and COND#2 were the most stable sensor pair so these were used in onboard data processing operations for both CTD and bottle data reports.
PRT#1 (after about sta92) was observed to jump about 0.0008 deg on casts greater that 3200M. It was usually observed on the upcasts coming through about 3300M then jumped back to overlap downcast trace when it comes back up - around 3000M. Could be a digital bit sticking in that channel (bit #5?).
Cond#1 sensor has a pressure effect on deep casts and will require a pressure fit correction.

Bottles:

10L Bullister style, SIO manufactured.
Bottles serial numbered 1-24 corresponded to the pylon tripping sequence 1-24 with the first bottle tripped being bottle #1.
Bottles serial numbered 1-24 were used on all casts.

Thermometers:

The SBE35 Ref temp sensor data was recorded on all bottle trips.
No DSRT's
CTD oxygen:

Oxygen data interfaced with the CTD and incorporated into the CTD data stream using a:
Sensormedics Oxygen Sensor s/n 6-12-07 sta 1-108
Sensormedics Oxygen Sensor s/n 6-12-08 sta 109
Sensormedics Oxygen Sensor s/n 6-02-08 sta 110-113

Transmissometer:

Wetlabs Cstar 25cm (Blue) Transmissometer c/n CST-244DB
Wetlabs Cstar 25cm (RED) Transmissometer c/n CST-245DB

Winches:

Forward Markey CTD winch used on all casts
No wire or winch problems throughout the cruise.

Station-Cast number assignments:

Cast numbers were assigned between the CTD and the Bio-Optical profiler depending on which was deployed first. Station 9 was the only station that the CTD was deployed on two casts.

B.2. Salinity analyses: Carl Mattson (SIO/ODF)

SALINOMETER TYPES SERIAL NUMBERS

Guildline 8400A Autosal 55-503
Guildline 8400A Autosal 48-263

WORMLEY standard water used:

Batch P-134
203 vials used
2 bad vials

Comments:

Autosals were configured for computer-aided measurement. The data were acquired on a PC.

#48-263 stations 1-113 24 deg bath temp

B.3. Oxygen water sample analyses: Carl Mattson and Ron Patrick (SIO/ODF)

Oxygens were run on all stations using a Dosimat UV-endpoint detection automatic titration system.

Comments:

No major problems, hardly any problems.
The titrator employed a Brinkman Dosimat 665 automatic burette and an Ultraviolet detection system interfaced with a PC for data acquisition and control.

B.4. Nutrient analyses: Carl Mattson and Doug Masten (SIO/ODF)

Nutrients were measured on all stations using a Technicon AA-II CFA system with a PC based acquisition system. Nutrients measured - NO2, NO3, PO4, SIO3.

Comments:

The system performed well with few problems. Data were reviewed by analysts and transferred to the processing computer for integration with other water sample data.

B.5. Chlorofluorocarbon measurements: Mark Warner and DongHa Min (UW)

The measurement of chlorofluorocarbons, CFC-11 and CFC-12, in seawater and the overlying atmosphere during the JES expedition (Hahnaro 7) were made using standard analytical techniques. The analysis was based upon the purge-and-trap technique described by Bullister and Weiss (1988) with a few modifications. The same volume of water for every sample was purged through the use of a glass sample chamber with a calibrated volume. Ultra high purity nitrogen (99.999% pure) was used as the carrier gas. (An analysis of the CFC content found less than 1 part per trillion of both CFC-11 and CFC-12). A Hewlett- Packard 5890-II gas chromatograph with electron capture detector was used to detect the CFCs. The analog output (voltage) of the detector was converted to a digital signal by a Hewlett-Packard 35900E and the digital chromatograms analyzed on a Sun Sparcstation LX using software developed by Peter Salameh for the AGAGE program. The results are reported on the SIO 1993 scale using a calibrated standard gas cylinder (#39765).

Only minor analytical difficulties were encountered during the cruise. The water sample is introduced into the sparging chamber through the glass frit. After Station 8, the stripping chamber was replaced due to the frit having become clogged with particles (probably from previous measurements of estuarine waters with high sediment loads). This greatly improved the flow through the stripping chamber and hence the efficiency with which gases were sparged from the sample. The sensitivity of the detector to an injection of a calibrated volume of the standard gas was steady during the cruise with a standard deviation of +/-0.90% for CFC-12 and +/-1.31% for CFC-11. Calibration curves were prepared while in port in Pusan and additional points were added to the curves during the course of the expedition. These additional points fitted the initial curve so that one calibration curve could be used for the entire 23 days.

The CFC concentrations in approximately 1220 seawater samples were analyzed during the expedition. Samples were collected from 111 of the 112 stations with the typical sampling strategy of alternating casts with complete coverage of the water column (16 to 20 samples) and casts where only 6 to 10 samples were collected at target depths (usually the bottom or the East Sea Intermediate Water layer). Of these 1220 samples, approximately 40 were duplicates from the same Niskin to establish the measurement precision. The shipboard measurements have been merged into the .SEA files. The precision appears to meet or exceed WOCE standards (standard deviation of 1.5% or 0.005 pmol/kg, whichever is greater). Surface CFC concentrations are at or slightly above the expected values based on Warner and Weiss (1985) solubilities. Since there are CFCs throughout the entire water column, the typical method of using the measured CFC concentrations in waters which should be CFC-free to estimate the sampling blank cannot be applied. Instead, the results of a experiment where CFC-free water in a Niskin, produced by bubbling nitrogen through the sample, is allowed to sit. By measuring the change in CFC concentration with time, the amount of contamination due to desorption can be estimated.

In preparation for the collection of samples during the expedition of the Professor Khromov, seawater samples were also collected in glass ampoules and flame-sealed for later analysis at the University of Washington. Ampoule samples were collected from 137 bottles immediately after the syringe sample for shipboard analysis was drawn. We plan for the Russians to collect approximately 700 samples during the Khromov trip. The comparison of the ampoules and shipboard measurements from this expedition will be critical to our interpretation of the stored samples.

The atmospheric concentrations of the CFCs were determined at 20 locations and times during the cruise. Air samples were pumped from the bow through Decabon tubing to the analytical system. The measured atmospheric concentrations of CFC-11 and CFC-12 both decreased with increasing latitude. The mean and standard deviations for the atmospheric CFC concentrations (in ppt) are:

CFC-11: 256.5 +/- 5.3
CFC-12: 538.8 +/- 8.3
CFC-113: 81.5 +/- 2.4

B.6. Alkalinity and pH: Pavel Tischenko (POI) and Dong-Jin Kang (SNU)

B.6.a. Pacific Oceanological institute (Pavel Tishchenko)

Samples were collected and analyzed for pH and alkalinity from every station. The methods and results of a comparison with the SNU system are described in B.6.c.

B.6.b. Seoul National University (Dong-Jin Kang)

Samples were collected and analyzed from 15 stations for comparison with the POI analysis. The methods and results are described in B.6.c.

B.6.c. Intercomparison of Alkalinity and pH measurements between SNU and POI: Preliminary Report (Dong-Jin Kang and Pavel Tischenko)

Introduction

The carbonate system in seawater is one of the most complex topics in oceanography. More recently the fate of fossil fuel CO2 in the ocean has promoted interests in the study of carbonate chemistry in the ocean. The biogeochemical cycle of CO2 in the ocean is controlled by its special pumping mechanism such as solubility, biological, carbonate, and dynamic pumps (Volk and Hoffer, 1985; Sarmiento et al., 1995). Among these pumps, dynamic pump is strongly related with circulation and/or ventilation of seawater. In order to quantify the dynamic pump, precise understanding the distribution of CO2 parameters is essential.

Four CO2 parameters can be measured, which are total dissolved inorganic carbon (CT), total alkalinity (TA), fugacity of CO2 (fCO2), and total hydrogen ion concentration (pH). These are used together with ancillary information to obtain a complete description of the carbonate system in seawater. It is only necessary to know two parameters from the four above to have a complete description of the system (Park, 1969; Skirrow, 1975). TA and pH are usually chosen since their procedures are simple to be carried out on board.

There are several methods to determine TA and pH in seawater. Methods for TA determination are single point titration, open-cell potentiometric titration, closed-cell potentiometric titration, colorimetric titration and so on. Potentiometric and spectrophotometric methods are used for pH determination in seawater.

The potentiometric titration measuring EMF in a closed cell ( Dickson, 1981; Bradshaw and Brewer, 1988; Millero et al., 1993; DOE, 1994) and s pectrophotometry using an indicator dye are, in general, accepted as modern analytical methods for the measurement of TA in seawater, respectively. Although it is considered that these methods give accurate information on the carbonate chemistry of seawater, those have some disadvantages when those are carried out on board. As for pH, the spectrophotometric performance of the instrument is not easy on board, which is one of the most important factors for precise determination of pH (DOE, 1994). It takes long time to analysis TA since the electrode needs times to adjust to changing EMF.

Seoul National University (SNU) uses spectrophotometry and closed-cell potentiometric titration for pH and TA measurements, respectively. The potentiometric pH measurement and direct colorimetric titration for TA are used by Pacific Oceanological Institute (POI).

On board intercomparison study was carried out during the Hahnaro-7 expedition on the East/Japan Sea. Around 130 seawater samples from surface to more than 3000 m depth were analyzed by both methods. The preliminary results are reported in here.

Methods and Materials

Total Hydrogen Ion Concentration (pH)

SNU used spectrophotometry using m-cresol purple as an indicator dye (Clayton and Byrn, 1993). The absorbances of seawater and sea water with dye are measured at three wavelengths (434, 578, and 730 nm) which are corresponding to the absorption maxima of acid (434 nm) and base (578 nm) forms of the dye and a non-absorbing wavelength (730 nm). The pH values are calculated from the absorbance of seawater and seawater + dye at three wavelength using the following equation.

A1 and A2 are the corrected absorbances measured at the wavelengths of 578 and 434 nm, respectively. pK2 is the acid dissociation constant for the species HI- which is a function of salinity and temperature (in K);

The various extinction coefficient ratios for m-cresol purple are as follows:

epsilon1(HI-)/ epsilon2(HI-) = 0.0069

epsilon1(I2-)/ epsilon2(HI-) = 2.222

epsilon2(I2-)/ epsilon2(HI-) = 0.133

All SNU data reported here are averaged value of duplicate analysis. The average precision of duplicate analysis is 0.006 pH unit is one standard deviation.

POI used potentiometric measurement in a potential cell without liquid junction for pH measurements of seawater, since it was reported that unreproducibility and loss of accuracy of potentiometric pH measurement are caused by liquid junction potential (Tishchenko and Pavlova, 1999).

Glass-electrode-Na+

Test (standard) solution

H+-glass-electrode

(A)

The cell (A) was calibrated by T RIS-buffer (DelValls and Dickson, 1998) at 25 oC and pH is calculated by formula:

where E, mNa, and g Na are EMF, sodium ion molality and activity coefficient of sodium ion, respectively; subscript indices s, x denote standard and test solutions, respectively. Activity coefficients of sodium ion have been calculated by Pitzer method (Pitzer, 1992) and approximated by empirical formula below.

Properties of sodium ion as follows

(mNa)s = 0.44618

(g Na)s = 0.6412

where S is salinity; I is an ionic strength which calculated by equation

Shift of a standard EMF of the cell (A) was less then 0.5 mV/ per day. The precision of pH measurement by means of the cell (A) is about ± 0.004 pH unit.

Total Alkalinity (TA)

SNU used potentiometric titration measuring EMF in a completely closed cell (Millero et al., 1993). The system is composed by a motor driven piston burette (5 mL, scale ± 0.01 mL) with anti-diffusion tip, titration cell assembly, and personal 0.02 computer for controlling burette and data acquisition from pH meter. Orion double junction Ag/AgCl reference electrode and ROSS glass electrode are used as reference and EMF electrodes, respectively. The titration cell and burette piston are inco rporated with outer water jackets which constant temperature (25.0 +- 0.1C) water circulates through. The titration procedure is controlled by personal computer through serial ports. Total alkalinity is calculated by non-linear least squares approach method (Dickson, 1981; Johansson and Wedborg, 1982; DOE, 1994).

Total alkalinity is normalized by Dicksons CRMs (Batch #46) which are measured at every station. It take 40 to 50 minutes to complete titration including flushing. The average precision of duplicate analysis is 4.5 umol kg-1 in one standad deviation.

POI used Bruevich's Method. In Russia a determination of total alkalinity is direct colorimetric titration by hydrochloric acid in an open system using a mixed indicator (methylene blue and methyl red). The titration is carried out under flow of CO2-free air (or nitrogen). The change of the sample color from green to light-pink at the equivalence point is detected by visually. The pH at the end point is about 5.4-5.5. The method is well-known as Bruevich's method (Bruevich, 1944) and recommended as standard operating procedure among Russian oceanographers (The methods..., 1978). The titration procedure is presented below.

The acid (~0.03 N) is standardized daily with Dickson's CRM. The calibrated 0.04 volumetric pipette (25 mL) is used. Twenty-five milliliters of the primary standard is placed in a titration cell. Three drops of the mixed indicator are added and the sample is flushed with nitrogen for 3 min to remove all the carbon dioxide. CRM is then titrated with hydrochloric acid using Dosimat 665 motor driven piston burette (5 mL, scale ± 0.01 mL). The equivalence point of the titration is determined 0.02 colorimetrically. The solution color at the end point of the titration must be light pink and quite stable (no change for 1 min). Seawater samples are analyzed using the same procedure. Total titration time takes about 7 min. Alkalinity is calculated by formula

TA=NaVa/(Vsw dsw)

Here, Na, and Va, are normality and volume of acid, respectively; Vsw and dsw are volume and density of seawater. Estimated precision is about 0.2% (4 ~ 5 umol kg-1).

The both methods are summarized briefly in Table 1.

Table 1. Summary of the methods for total alkalinity (TA) and pH by Seoul National University (SNU) and Pacific Oceanography Institute (POI)

SNU

POI

TA

Cell type

Closed

Open

End Pt detection

EMF

Visual Indicator

Calculation

Non-linear Least Square < /TD>

Algebraic formula

Acid

~ 0.25 N HCl

~ 0.02 N HCl

Acid Std.

Na2CO3 and CRM

Na2CO3 and CRM

Precision

4.5 umol kg-1

4 ~ 5 umol kg-1

PH

Spectrophotometry

Using mCP

EMF

Without liquid junction

Precision

0.006

0.004

Materials

During the Hahnaro-7 expedition in the East(Japan) Sea from 24th June to 17th July, 1999, around 130 real seawater samples from the surface to more than 3500 m depth at 12 stations were used for intercomparison (Table 2).

 

Table 2. Locations, water depth (in meters), and number of samples of each station for intercomparison of total alkalinity and pH measurements between SNU and POI.

Sta. #

Latitude

Longitude

Depth

No. of Samples

4

34 49.9 N

130 11.9 E

124

7

13

36 12.0 N

132 27.6 E

1074

10

26

37 3.45 N

130 56.2 E

2207

7

41

37 53.7 N

129 44.1 E

1626

8

45

37 53.8 N

132 41.8 E

2530

11

57

40 50.0 N

134 00.0 E

3530

13

58

41 10.0 N

136 20.0 E

3450

13

72

37 11.0 N

135 32.1 E

1739

13

77

38 38.0 N

136 00.0 E

2725

12

80

39 59.8

138 00.1 E

2420

11

95

42 0.00 N

138 00.0 E

3585

13

108

43 47 N

138 50 E

2970

?

Results

Total Hydrogen Ion Concentration (pH). The pH values of two laboratories are in a good agreement (Fig. 1). However, the slope between two data sets is about 5 % greater than equivalence (pHPOI = 1.056 x pHSNU - 0.479, r2=0.991). The differences between two are almost within 0 +- 0.1 when pH value is higher than 7.8 with some exceptions. While, in the case of smaller pH values than 7.8, the differences increase linearly as pH values decrease. It becomes about 0.35 at pH value of 7.5 (Fig. 2). This difference (0.35) is not negligible compared with precisions of both methods (0.004 ~ 0.006). Since typical profile of pH in the region (East/Japan Sea) shows around 7.5 of pH from 200 ~ 300 m depth to the bottom (Fig. 3), it can be said that there are differences in vertical distributions between two methods. The reason of the difference is to be studied carefully in the future.

Total Alkalinity (TA). Normalized total alkalinity (NTA = TA x 35/S; S represents salinity) values of two laboratories show linear relationship, in general. How ever, it is seemed that there is a systematic difference between two methods (Fig. 4). POI values (open cell) are smaller to about 5 ~ 10 umol kg-1 than SNU values (closed cell). In the PICES WG13 intercomparison workshop, which was held at Tsukuba, Japan in April, 1999, the closed system shows higher values and open system shows lower than mean values for samples of high pCO2 concentration. This study gives coincident results with those of the PICES intercomparison workshop.

The differences between two methods increase as NTA increases until NTA reaches around 2330 ~ 2340 umol kg-1, and then it can be said that the differences keep constant in the range of NTA higher than 2340 umol kg-1 (Fig. 5). From the vertical profiles, NTA of this range is found within 100 and 500 m (Fig. 3), which is similar with the depth which shows constant pH differences.

The causes of the differences between two methods will be studied carefully in the future.

References

Bruevich C.V. 1944. Determination alkalinity of small volumes of seawater by direct titration. In: Instruction of chemical investigation of seawater. Glavsevmorput, M.-L., 83p.

Clayton, T.D. and R.H. Byrn, 1993. Spectrophotometric seawater pH measurements: total hydrogen ion concentration scale calibration of m-cresol peurple and at-sea results. Deep-Sea Res., 40: 2115-2129.

DOE, 1994. Handbook of methods for the analysis of the various parameters of the carbon dioxide system in sea water. Version 2, A.G. Dickson and C. Goyet eds., ORNL/CDIAC-74

Dickson, A.G., 1981. An exact definition of total alkalinity and a procedure for the estimation of alkalinity and total inorganic carbon from titration data. Deep-Sea Res., 28A; 609-623.

Ivanenkov V., O, Bordovsky, 1978. The methods of hydrochemical investigation of the ocean. 271p. Nauka, Moscow, (in Russian).

Johansson, O. and M. Wedborg, 1982. On the evaluation of potentiometric titrations of seawater with hydrochloric acid. Oceanol. Acta, 5: 209- 218.

Millero, F.J., J.-Z. Zhang, K. Lee, and D.M. Campbell, 1993. Titration alkalinity of seawater. Mar. Chem., 44: 153-166.

Park, K., 1969. Oceanic CO2 system: an evaluation of ten methods of investigation. Limnol. Oceanogr., 14: 179-186.

Pitzer K.S. Ion interaction approach: Theory and data correlation.// Activity coefficients in electrolyte solutions. 2nd Edition/ K.S.Pitzer Ed. Roca Raton Ann Arbor Boston London: CRC Press, 1991. p.75-153.

Sarmiento, J.L., R. Murnane, and C.Le.Quere, 1995. Air-sea CO 2 transfer and the carbon budget of the North Atlantic. Phil. Trans. R. Soc. Lond. B, 348: 211-219.

Skirrow, G., 1975. The dissolved gases-carbon dioxide. In Chemical Oceanography, v. 2, J.P. Riley and G. Skirrow eds., 1-912.

Tishchenko P.Ya. and G. Yu. Pavlova, 1999. Standardization of pH measurements of seawater by Pitzer's method. In: CO2 in the Oceans, Extended Abstracts, Tsukuba.

Volk, T. and M.I. Hoffert, 1985. Ocean carbon pumps: Analysis of relative strength and efficiencies in ocean-driven atmospheric CO2 changes. In The carbon cycle and atmospheric CO2: natural variations archean to present, E.T. Sundquist and W.S. Broecker eds., 99-110.

Figure Captions

Fig. 1 A plot of pH values from SNU and POI. The units are in total hydrogen ion scale (THIS).

Fig. 2 A plot of pH differences between two methods vs. pH values of SNU. The units are same as Fig. 1.

Fig. 3 Vertical distributions of pH and normalized total alkalinity (NTA) for all stations. The units of NTA are in umol kg-1. The depths are from the wire out data.

Fig. 4 A plot of normalized total alkalinity (NTA) values from SNU and POI. The units are same as Fig. 3.

Fig. 5 A plot of NTA differences between two methods vs. NTA values of SNU. The units are same as Fig. 3.

B.7. Noble Gas and Tritium Sampling: Clare Postlethwaite (IOS)

280 water samples from 22 stations, located mainly in the deepest parts of the basins and also in the straits, were collected for noble gas and tritium analysis. Water samples were collected from the rosette in 15mm diameter copper tube for analysis of helium, neon, argon and possibly krypton and xenon. The copper tube was cold sealed and the samples were packed safely for later analysis. All noble gas samples were collected in duplicate and several samples were collected in quadruplicate. The noble gas measurements will help to quantify the influence that the seasonal sea ice in the Tatarskiy Strait has on water mass formation in the Japan/East Sea.

Samples for tritium analysis were collected concurrently to the noble gas samples so that tritium/helium dating is possible. These samples were collected in one litre glass bottles that had been pretreated by heating to 200 degrees centigrade in an argon atmosphere. During sampling the bottles were not rinsed and a head space was left. These samples were also packed for later analysis at the Noble Gas Laboratory at the University of Southampton, U.K.

B.8. Oxygen Isotope Sampling: Clare Postlethwaite (IOS)

100 water samples from 11 stations were collected in 300ml glass bottles for the analysis of oxygen isotopes. The glass bottles had been treated in the same way as those for tritium analysis. The stations chosen for the noble gas and tritium analysis as the volumes of water taken in the samples may be sufficient to allow both tritium and oxygen isotope analysis from both the 1 litre and 300 ml bottles thereby providing more data.

B.9. Other SNU sampling (helium, tritium, D-14, Del 18O, SF6): Dong-Jin Kang (SNU)

Samples for other tracers were collected for SNU. The numbers of stations for each tracer are 9 for helium and tritium, 6 for C-14, 23 for Del 18O of water, and 1 for SF6. All of these will be measured in the laboratory. Helium and tritium will be determined by noble gas mass spectrometer after series of pretreatment. C-14 will be measured by Accelerating Mass Spectrometer from CO2 extracted in seawater. Del 18O will be analyzed using stable isotope ratio mass spectrometer. SF6 will be measured by GC/ECD.

B.10. Underway pCO2 measurements: Dong-Jin Kang, Doshik Hahm (SNU)

B.10.a. pCO2 measurements. Continuous measurements of pCO2 in surface water and marine air were made with a laboratory made system. The system is composed with an NDIR (Licor LI-6252), valve sets, and Weiss type equilibrator. The system is controlled and data are acquired at every second by laboratory made program in LabVIEW on a PC. Two kinds of standard gas were measured every day. Marine air and equilibrated air with surface seawater were measured alternatively was measured at every other cycle of marine and equilibrated air.

B.10.b. Thermosalinograph measurements. Salinity, temperature, and chlorophyll fluorescence were measured at every minute with Seabird thermosalinograph (SBE 21) with Wet Lab fluorometer. The location was recorded at every minute with GPS (Trimble NT100). The temperature and conductivity sensors were calibrated two months before the cruise by manufacturer.

B.10.c. Underway chlorophyll sampling. To calibrate the fluorometer, chlorophyll samples were taken every 12 hours. About 4 liters of samples were collected from the outlet of fluorometer, and filtered immediately using GF/F. After more than 24 hour extraction with 90 % acetone, chlorophyll concentration was determined by Turner design fluorometer by Dr. G. Mitchell.

B.11. Acoustic doppler current profiling (ADCP): Lynne Talley (SIO) and Peter Hacker (U. Hawaii)

B.11.a. Lowered ADCP.

A 150 KHz RD Instruments acoustic doppler current profiler was integrated with the CTD/rosette package. The LADCP makes direct current measurements at the depth of the CTD, thus providing a full profile of velocity. The LADCP was used at every station. The shipboard data acquisition system for the LADCP permits data acquisition on a laptop PC and very preliminary processing on a small Sparc workstation. When the data set is returned to SIO and the U. of Hawaii, preliminary processing will determine if the data set is useful for processing. Criteria include the presence of scatterers in the water column and good data profiles. Assuming that the data set is useful, data processing will be carried out by Scripps and U. Hawaii researchers Preliminary profiles plotted from the LADCP at sea indicate that the data set looks promising and useful. (Talley group at SIO; Hacker/Firing group at U. Hawaii).

B.11.b. Underway ADCP.

ADCP data were recorded by the Revelle computer system. Rudimentary processing was carried out during the cruise to ensure that data files were complete. Preliminary checks suggest that no data were recorded for the interval between CTD stations 57 and 58.

B.12. Meteorology: R/V Revelle (Talley; SIO)

IMET data were recorded at 30 sec intervals on the ship's underway system.

Sensors: Air Temp, RH, Barometric pressure, SWR, LWR, Precipitation, Wind Speed/Direction, Sea Surface Temperature/Conductivity. Data merged with Ships navigation, gyro and time server.

B.13. Navigation: R/V Revelle (Talley; SIO)

Navigation was recorded from both a P-code GPS and an Ashtech GPS. The P-code recorded data were corrupted for the period July 7, 1999 at 1043 to July 7, 1999 at 2356. Positions were restored from the Ashtech GPS for this period for the data file that was distributed at the conclusion of the cruise. There was apparently no problem with the real-time positions displayed on the bridge and in the lab, and so the station positions are correct.

B.14. Bathymetry: R/V Revelle (Talley; SIO)

Underway bathymetry from the center return of the Revelle's Seabeam was recorded and stored for use with the vertical sections. Bathymetry from the Knudsen echosounder was also recorded, and was used to restore portions of the Seabeam bathymetry which were not recorded. These include the Tsushima Strait section (stations 1 to 7) and the segment between stations 27 and 29, at times 990629 0453, June 29 to 0939, June 29. The Knudsen echosounder also was not functioning for a portion of the missing Tsushima Strait section and so detailed underway bathymetry is not available for this portion.

B.15. Video Plankton Recorder (VPR): Carin Ashjian and Cabell Davis (WHOI)

We described aspects of the biological oceanography of the Japan/East Sea, in particular how plankton communities and abundances changed in the different hydrographic regimes. Our research had three primary objectives: 1) To characterize the zooplankton community of the Japan Sea in terms of taxonomic composition and size structure, 2) To characterize the scales of variability of the zooplankton over distances from centimeters to hundreds of kilometers, and 3) to determine the relationship between zooplankton taxa and associated environmental variables over scales from centimeters to hundreds of kilometers. To achieve these goals, we conducted a survey of the southern Japan Sea using the Video Plankton Recorder. The Video Plankton Recorder (VPR) is essentially an underwater microscope which images plankton at two different magnifications. The instrument is mounted on a V-fin which was towed behind the ship, undulating between the surface and a selected depth. Video images and associated hydrographic and biological data are transmitted from the towed vehicle to the ship via fiber optic cable. In-focus images of plankton are extracted from the video and identified to taxa in real time. Plankton abundances and hydrography are plotted in real time.

During the survey of the JES, we towed the VPR at ~9 knots between all CTD stations along the transect lines. We sampled over a total distance of 356 2 kilometers and collected and processed over 240 hours of video and associated data. The instrument sampled between near surface and 80 m for much of the survey with an inter- profile distance of ~7 kilometers.

In addition to the plankton images, we collected pressure, temperature, conductivity, fluorescence, light transmission, and ambient light data as well as logging P-Code GPS position and time (UTC) and Knudsen Echo Sounder depth. Real-time plots of hydrographic (T, S, density) and biological (fluorescence, light transmission, unidentified copepods, diatom chains, and Oithona) showed strong vertical structure in plankton distributions that were associated with the physical environment (e.g., thermocline) and regional differences in the type and abundance of plankton.

Future analyses will include: 1) describing the size distribution of taxa, 2) quantifying associations between different taxa and between taxa and environmental conditions, 3) examining the scale of variability of the distributions of zooplankton taxa, and4) incorporating instantaneous velocity measurements collected with the shipboard acoustic Doppler current profiler to estimate of flux of plankton between different hydrographic regions and in and out of the JES.

B.16. Plankton net tows: Carin Ashjian and Cabell Davis (WHOI)

We conducted 15 plankton tows using a 1-m2 (mouth area), 150 B5m mesh ring net towed obliquely between the surface and 80 m. Initial inspection of the samples indicated strong variation in taxonomic composition between the different regions. The plankton samples assisted us in identifying exotic taxa that were seen in the video images.

B.17. Bio-optical studies: Greg Mitchell (SIO)

There are three primary goals of the work:

1. Calibration and validation of SeaWiFS Ocean Color satellite. Above water spectral reflectance and atmospheric optical depth was collected with a SIMBAD hand-held radiometer during day-time CTD profiles. The SIMBAD views the ocean surface from above, and the direct beam of the sun to derive spectral reflectance. This above-water optics was supported by water samples including preparations for chlorophyll a, HPLC pigments, absorption by particles and soluble material, particulate organic carbon and inorganic minerals.

2. Parameterizations of ocean attenuation and chlorophyll specific absorption for ocean photosynthesis models. Samples were collected within the euphotic zone, as determined by Secchi Depth, to characterize both particle and soluble absorption coefficients. The particulate material was partitioned to phytoplankton and detrital components using methanol extraction and difference spectroscopy. Chlorophyll-specific phytoplankton absorption coefficients will be used for photosynthesis models. The total particle and soluble absorption will be used to model spectral attenuation coefficients of the euphotic zone.

3. Application of beam attenuation coefficient as an augmentation to CTD hydrographic profiles for determining water mass structure and circulation. Red and blue wavelength beam attenuation meters (transmissometers) are integrated with the SIO CTD system and data were collected for all CTD profiles. Water samples through out the full depth of the profiles were collected from selected stations and selected depths to characterize particulate organic carbon, particle and soluble absorption, and presence of different mineral components. Attenuation coefficients will be correlated to vertical structure in hydrographic parameters including oxygen, nutrients, salinity and temperature.

Typical station plan Water from the CTD Rosette system was collected for the surface and selected depths for selected stations (usually daytime only stations to support SIMBAD and SeaWiFS). Water was prepared by vacuum filtration in the lab. Absorption samples were analyzed on the ship. Other samples have been stored in liquid nitrogen for return shipment to SIO for analysis.. Mineral optics water samples were preserved with glutaraldehyde in glass bottles for return shipment to SIO.

Equipment

Wet Labs Cstar beam attenuation meter (red) CST-245DR
Wet Labs Cstar beam attenuation meter (blue) CST-244DB
Varian Cary 1E UV/Visible spectrophotometer 95061306
Univ. Lille SIMBAD ocean reflectance radiometer 972308

C. Distribution of data and samples to groups other than originating principal investigators

CTD data: Pavel Tischenko (POI), Vladimir Luchin (FERHRI) (7/18/99)

Water sample data (salinity, oxygen nutrients, CFCs, alkalinity, pH): Pavel Tischenko (POI), Vladimir Luchin (FERHRI), Lynne Talley (SIO), Mark Warner (UW), DongHa Min (UW), Clare Postlethwaite (IOS), Dong-Jin Kang (SNU) (7/18/99)

Lowered ADCP data: Pavel Tischenko (POI), Vladimir Luchin (FERHRI) (7/18/99)

Underway meteorology (IMET) and surface temperature/conductivity, bathymetry, navigation: Pavel Tischenko (POI), Vladimir Luchin (FERHRI), Carin Ashjian (WHOI), Dong-Jin Kang (7/18/99)

Underway ADCP data: Carin Ashjian (WHOI) (7/18/99)

pCO2 data: to be processed and distributable by 1/1/00.