A.   Cruise Narrative:  A03

A.1. Highlights
                        WHP Cruise Summary Information

             WOCE section designation  A03
    Expedition designation (EXPOCODE)  90CT40_1
          Chief Scientist/affiliation  Vladimir Tereschenkov, SOI* 
                                Dates  1993 SEP 11 - 1993 NOV 21
                                 Ship  R/V Professor Multanovskiy
                        Ports of call  St. Petersburg-Hamburg-Woods Hole
                                       Woods Hole-Hamburg-St. Petersburg
                   Number of stations  133
                                                   38°14.36'N
Geographic boundaries of the stations  08°31.58'W                73°40.36'W
                                                   36°11.06'N
         Floats and drifters deployed  none
       Moorings deployed or recovered  none
  
                 Contributing Authors  S. Dobroluybov  Ev. Yakushev
                                       S. Borodkin     V. Konnov

      *Shirshov Institute of Oceanography ~ Krasikova 23 ~ Moscow  117218
                              Russian Federation
                  Fax: 7-095-124-5983 ~ email: rocc@sovam.com



B.1  CRUISE SUMMARY

Cruise Track
The cruise track and station location are shown (in PDF doc.).

SAMPLING ACCOMPLISHED

Water sampling on the cruise included measurements of salinity both by CTD and 
water bottle samples, bottle sample oxygen determination, CTD and DSRT 
temperature, CTD and UDSRT pressure, nutrients (silicate, nitrate, nitrite and 
phosphate).

TYPE AND NUMBER OF STATIONS

During the occupation of A3 section a total of 133 CTD/rosette stations were 
occupied using 24-bottle rosettes. 98 XBT stations were occupied on a track 
along 48°N.

B.2  List of Principal Investigators

     TABLE 1: Principal Investigators for All Measurements

            Name             Responsibility  Affiliation 
            ---------------  --------------  -----------
            V. Tereschenkov  CTD             SOI      
            U. Reva          CTD             SOI      
            S. Dobroluybov   Salt            MSU      
            V. Konnov        Nutrients       IO RAN   
            Ev. Yakushev     Oxygen          IO RAN   
                             Nutrients
            S. Borodkin      Oxygen          IO RAN


B.3  PRELIMINARY RESULTS

The ship departed from St. Petersburg on September 11, 1993.  On September 15-17 
the ship made a stop at Hamburg.  During this stay some problems concerned with 
scientific equipment and supplies were solved due to generous assistance of 
oceanographers from BSH.  On 21 of September two stations were occupied near 
45°N 8.5°W location to test the CTD/rosette system and to define the quality of 
the sampling bottles and the operating state of the ship boarded equipment.  The 
first station on A3 section was occupied on September 24.  The whole section was 
completed in 32 days with total of 133 stations occupied.  Space resolution 
between the stations varied from 29 n. miles in the open ocean to 8 n. miles in 
the boundary regions. On each station a CTD/rosette cast was carried out, that 
extended as close to the bottom as it was possible, considering the bottom 
detection uncertainties.  On the up cast up to 24 water samples were taken.  
After the rosette was brought on board, water samples were drawn in the 
following order: oxygen, nutrients, and salinity.  The chemical analyses were 
routinely conducted soon after the samples were collected.

Two CTD/rosette systems were used in the cruise for the seawater temperature and 
conductivity profiling and water sampling collection purposes:

 o EG&G NBIS Mark-III CTD together with the GO Rosette equipped  with
   24 1.7l GO Niskin bottles
 o "Hydrozond-6000" CTD together with 24 position rosette with 11 PVC
   bottles (manufactured by Central Construction Bureau of Hydromet
   Instruments, Russia).

Water temperature and pressure were also measured by mercury Deep-Sea Reversing 
Thermometers (protected and unprotected, respectively).  The conductivity of the 
bottle water samples was determined using Guildline Laboratory Autosal 8400A and 
than transformed to salinity according to equation of the Practical Salinity 
Scale of 1978 (UNESCO, 1981).  The dissolved oxygen analyses were carried out 
using Winkler method.  The silicate and nitrate plus nitrites analyses were 
performed using AKEA Flowcomp 1500 auto analyzer, phosphate was determined using 
KFK-3.  Details of calibrations, methods, techniques and accuracies are 
documented below.

During the ships movement along the A3 line continuous depth recording has been 
conducted using ELAG echo sounder.  On October 27-30 the ship made a call to 
Woods Hole for the refill.  There is a pleasant and productive communications 
with WHOI people had occurred.  After that "Professor Multanovskiy" occupied an 
XBT section similar to A2 line.  Total of 98 Sippican T-7 probes were dropped at 
synoptical space resolution.  On November 14-17 the ship visited Hamburg, where 
the XBT data and some scientific equipment were passed to scientist from BSH and 
the results of the first view data analyses have been discussed.

On November 21 ORV "Professor Multanovkiy" returned to St. Petersburg.


B.4  PROBLEMS

During an occupation of station 31 (Sept. 30 1993) the Niel Brown Mark-III CTD 
underwater unit together with the GO Rosette slipped off the cable and was lost.  
After that the backup instruments were used.  The problems arise since that 
moment were all connected with the unstable performance off the "Hydrozond-6000" 
sensors.  Nevertheless the natural desire to get the best of the data caused the 
departure of the post-cruise data processing procedure from the scheduled 
routine.  That is why the final version of the CTD data is still not available. 

B.5  Other Incidents of Note
     none


B.6  List of Cruise Participants

     TABLE 2: Cruise Participants.
           
            Name             Responsibility    Affiliation 
            ---------------  ----------------  -----------
            V. Tereschenkov   Chief Scientist   SOI      
            A. Sokov          CTD               SOI      
                              Rev.Instrum.                
            S. Pisarev        CTD               SOI      
            U. Reva           CTD               SOI      
            A. Andreev        CTD               SOI      
            S. Grigoriev      Software          SOI      
            S. Dobroluybov    Salinity          MSU      
            V. Konnov         nutrients         IO RAN   
            Yu. Konnova       nutrients         IO RAN   
            Ev. Yakushev      Salts,oxygen      IO RAN   
            S. Borodkin       oxygen            IO RAN   
            V. Bulanov        Hardware          VNIIRO   
            S. Yunovidov      Hardware          AARI     
            A. Tarasov        Watch Stander     AARI     
            A. Nikankin       Watch Stander     AARI     

C.   CTD MEASUREMENTS

C.1  CHIEF SCIENTIST OVERVIEW

The ship occupied total of 133 hydrographic stations along A3 (WHP-ID) section.  
Detailed information on stations' position can be found in 90CT40.sum file.  The 
stations were occupied from the surface to the bottom with respect to the fact 
that the sounding instruments in use were not equipped with the altimeter.  Thus 
precautions were taken to avoid the contact of the instrument with the bottom, 
what resulted in the absence of near bottom observations.  The first 31 stations 
were carried out using the NBIS Mark-3B CTD system owned by the VNIIRO (Russian 
Fishery and Oceanography Institute, Moscow Russia).  The rest of the stations 
were occupied with the Hydrozond-6000 CTD system, possessed by the AARI (Arctic 
and Antarctic Research Institute, St. Petersburg, Russia).  The latter 
instrumentation was produced by Central Design Bureau of the Hydromet 
Instruments (Obninsk, Russia).

The switch of the CTD occurred due to unexpected loss of the NBIS CTD device, 
which sledded off the cable wire on the way up and drowned.  The reasons of the 
accident were thoroughly investigated.  The conclusion indicated the 
malfunctioning of the "frog-type" grasping mechanism and no operator fault.

In any case the following information will be concerned with both measuring 
systems.

C.2  CTD DATA COLLECTION AND PROCESSING.

C.2.1  CTD DATA ACQUISITION

Three channels (pressure, temperature, conductivity) were acquired by the NBIS 
Mark-B CTD at a data rate of 15.85 Hz and Hydrozond-6000 at a data rate of 4 Hz.  
The CTD signal was demodulated by a deck unit and output to an RS-232 bus 
interface.  A 386DX IBM PC with a 120 Mb hard disk and 1 Mb RAM was used as the 
primary data collection device.  The data from NBIS CTD has been logged in the 
computer using EG&G Oceansoft MkIII/SCTD Acquisition Software package.  The data 
from Hydrozond-6000 was logged using a software package developed by SOI 
computer group.  Each cast data were transferred to Phillips 386DX computer with 
640 Mb hard disk and 8 Mb memory for further processing.  A backup of all the 
data was stored on magnetic cartridge tape and magnetic diskettes.

C.2.2  CTD LABORATORY CALIBRATIONS

The manufacturer's sensor specification is given in Table 3.  The pre-cruise 
calibration was performed only for the NBIS Mark-3B CTD.

The laboratory calibration was performed by VNIIRO group, using EG&G Ocean 
Products calibration stand.  All the standards have been certified by both the 
US and Russian National Standards Bureau.  The post cruise calibration of the 
unit was impossible due to the loss of the instrument.

The Hydrozond-6000 sensors were not calibrated in the laboratory water bath at 
all.  According to the routine adopted by the Russian Hydrometeorological 
Service the supervisor of the CTD owner AARI, only the scheduled check and 
correction of the resistant bridges of the measuring circuit were fulfilled two 
month prior to the cruise.


TABLE 3: Manufacturer CTD sensor specification.

                           NBIS Mark-3B           Hydrozond-6000                                                     
Sensors               resolution  accuracy    resolution  accuracy
-------------------   ----------  --------    ----------  --------
Pressure,  dbar | %     0.1        6.5           1         0.5%  
Temperature,  ¯C        0.0005     0.005         0.01      0.02   
Conductivity, mS/cm     0.001      0.005         0.01      0.03   


C.2.2.1 PRESSURE TRANSDUCER CALIBRATION

NBIS CTD Paine Instruments pressure transducer was calibrated in a temperature 
controlled bath by comparison with the pressures generated by an EG&G Chandler 
Engineering 58-001J-T-1 piston pressure gage.  The calibration tests showed the 
accuracy of the CTD sensor of ± 2 dbar in a pressure range 0-9000 psi with 
respect to the loading - unloading hysteresis.


C.2.2.2 PRT TEMPERATURE CALIBRATION

The NBIS CTD Rosemount PRT temperature sensor was calibrated in a temperature 
controlled bath by comparison to a standard PRT used in EG&G Ocean Products 
calibration system.  The latter was checked against the known water and diphenyl 
ether triple point cells.  The calibration tests showed the agreement of the two 
sensors readings within ± 0.002°C.


C.2.3  FIELD CALIBRATION

As long as Hydrozond-6000 sensors were not calibrated at the laboratory, the at 
sea calibration was the only one applied to the sensors readings, based on the 
comparison with the bottled salinity and the pressure and temperature 
observations obtained by thermometric method using mercury DSRT and UDSRT.  Same 
means were used to control the NBIS pressure and temperature sensor performance 
and to calibrate the NBIS CTD conductivity sensor.

The field calibration routine was performed by producing a polynomial fit of the 
CTD pressure, temperature and conductivity readings with the appropriate 
measurements of the onboard salinometer and reversing thermometers.  The CTD 
values obtained by averaging the CTD sensors readings taken during 15 seconds 
before the bottles were fired and thermometer racks reversed.  The bottles not 
equipped with the thermometer racks were kept at the sampling level for 30 
seconds, otherwise they stayed unmoved for 3 minutes, the time interval adequate 
for thermometers to stabilize.  All the data selected for calibration was 
subjected to 2.8 standard deviation rejection.

These procedures require an established level of confidence in the auxiliary 
observational tools.


C.2.3.1 DSRT AND UDSRT

During the cruise the DSRT and UDSRT produced by Gohla Precision (Kiel, Germany) 
were implemented (see Table 4). The possibility to utilize the temperature and 
pressure values determined by these instruments for needs of CTD calibration is 
based on the research of Quadfasel, Verch and Langhof (1991).

One of the advantages of the mercury thermometers is their highly stable time 
behavior. The time drift of the measurements is shown to be only ± 1.4 mK/year.

Calibration of the Gohla Precision instruments is done with an accuracy of 
0.001°C.


TABLE 4: Gohla Precision DSRT and UDSRT summary.

      Instrument  Serial #    Range      Etching  Calibration date 
      ----------  --------    --------   -------  ----------------
        DSRT       11459       -2 + 6      0.01       17.07.90       
                   11709       -2 + 6      0.01       17.01.92       
                   11818       -2 + 6      0.01       25.11.91       
                   11817       -2 + 6      0.01       25.11.91       
                   11816       -2 + 6      0.01       25.11.91       
                   11738       -2 + 16     0.02       16.01.92       
                   11739       -2 + 16     0.02       21.11.91       
                   11741       -2 + 16     0.02       21.11.91       
                   11835       -2 + 16     0.02       21.11.91       
                   11959       -2 + 35     0.1        19.11.91       
                   11960       -2 + 35     0.1        19.11.91       
                   11626       -2 + 35     0.1        09.11.90       
                   12067       -2 + 35     0.1        19.11.91       

       UDSRT       11519      +30 + 60     0.1        16.05.91       
                   11520      +30 + 60     0.1        16.05.91       
                   11521      +30 + 60     0.1        16.05.91       
                   11428       -1 + 35     0.1        30.05.90       
                   11427       -1 + 35     0.1        30.05.90       
                   11426       -1 + 35     0.1        30.05.91       
                   11492       -2 + 60     0.2        07.06.90       
                   11491       -2 + 60     0.2        07.06.90       
                   11695       -2 + 60     0.2        27.11.91       


The manufacturer claims the accuracy of the thermometers to be 0.5 of the 
etching interval.  But with the experienced observers we believe it to be 0.2 of 
the etching interval.

The field test of the thermometers was performed on a test station.  All the 
thermometers were reversed on the same level within the homogeneously stratified 
water layer.  The standard deviation of the high resolution DSRT was 0.005°C.  
These instruments were mainly used for calibration purposes.  The scatter of the 
low-resolution thermometers was within ± 0.01°C.  These DSRT were used in 1-2 
racks put above the thermocline.  Same tests were performed several times during 
the cruise with similar results.

At the first 31 station the pairs of DSRT were changed all the time.  And in all 
cases the difference between the measured temperatures was less than the 
warranted accuracy.  After that the combinations of the DSRT stayed permanent.  
The differences between the reading of the DSRT and UDSRT in the same rack 
didn't change with time confirming the time stability of the instruments.  The 
variations between the pressure measurements carried out by different UDSRT 
agreed within 0.3% of the depth.

The thermometric measurements of pressure and temperature were supervised by A. 
Sokov (now at P.P. Shirshov Institute of Oceanology).


C.2.3.2 BOTTLE SALINITY

The water sample salinity were measured with a Guildline Autosal Model 8400A 
salinometer N54403 that was standardized daily (usually twice) with IAPSO 
Standard Sea Water Batch 115.  The last calibration of the salinometer was 
carried out by Guildline representation on May 1991.  All measurements, initial 
quality control and shipboard data-processing were performed by S.A. Dobroliubov 
(Moscow State University).  A total of 3094 water samples from 132 stations 
(more than 23 samples per each) were analyzed for salinity including 80 
replicates.

Salinity samples were collected strictly according to WHP Manual (Stalcup, 
1991).

The published accuracy of the 8400A salinometer according to Operating Manual is 
0.003 psu.  But if measurements are made in a laboratory with quasi-constant 
temperature ±1°C (as in our case) it should be possible to reach the precision 
better than 0.001 psu.  All the procedures to attain highest accuracy described 
in the Operating Manual (section 6.5) were performed.  Mean difference between 
standardizations was 0.0004 psu.  These shifts were linearly interpolated 
between the first and the last sample readings.  The salinometer readings were 
inverted to salinity in accordance with Guildline Operational Manual formula and 
Practical Salinity Scale-1978.

Autosal calibration control was performed weekly with a simple suppression switch 
check described by Stalcup (1987).  This check showed the absence of any 
discontinuities. Another data control included replicate analysis. 21 pair of 
samples were collected from the same 1.8 l Niskin bottles at different stations. 
Module mean difference between the salinities of these pairs was 0.0007 psu with 
standard deviation 0.0006 psu.  The same procedure was promoted with Hydrozond-
6000 1.2 l bottles.  59 replicates were collected including two calibration casts 
and its analysis revealed module mean salinity difference of 0.0009 psu with 
standard deviation 0.0007 psu.  From this point of view the difference in 
measurements' accuracy with both types of bottles was considered to be 
statistically insignificant.


C.2.3.3 NBIS MARK-3B VS. THERMOMETRIC PRESSURE AND TEMPERATURE

Statistics of NBIS Mark-3B temperature and pressure comparison with DSRT 
(temperatures) and UDSRT (pressure) observations is presented in Table 4.  The 
good agreement is a justification for DSRT and UDSRT measurements application to 
Hydrozond-6000 calibration.


C.2.3.4 HYDROZOND-6000 PRESSURE CORRECTION

The Hydrozond-6000 CTD uses three separate pressure sensors each working in a 
certain pressure range without any overlaps.  The switch between the sensors 
occurs at prescribed pressure readings that are 320 and 1780.  The switch 
between the sensors was accompanied by a jump in pressure readings.  So for each 
station these jumps were determined and eliminated by applying a local pressure 
offset to the preceding readings in order to ensure the continuous records.

The analyses of the initial pressure records also revealed consistent 
peculiarities in the sensor behavior. All the records had a noticeable "silence" 
zone.  That is by reaching certain pressure (reading) 1000 and 3100 the readings 
didn't change for approximately 40 and 250 seconds consequently.  To avoid this 
effect and maintain the gradual pressure change, the averaged pressure time 
increment was calculated for periods of 30 seconds before and after the 
"silence" zone.  Than the difference between the time increment was linearly 
distributed for time interval corresponding to the constant pressure segment and 
used to model the real pressure behavior.  The pressure offset that occurred at 
the end of the "silence" zone was applied to the preceding pressure readings.


C.2.3.5 HYDROZOND-6000 PRESSURE CALIBRATION

As long as all the bottle samples were drawn during the CTD up cast and without 
a lab pressure calibration we had to trip some bottles with the thermometers 
racks on the way down in order to determine the pressure loading calibration.  
This has been done during the occupation of three special pressure calibration 
stations and several times with one bottle fired on a downcast during the 
routine work.  All together 39 observations were selected to perform the loading 
pressure calibration.

Fitting of (both loading and unloading) CTD and thermometric pressures was done 
by a third order polynomial.

Special attention was paid to the detected Hydrozond-6000 pressure hysteresis.  
To obtain the up cast pressure the following formula was used:

        Pcor = Pmes - (ofs dn + (ofs up-ofs dn)/Pmax*(Pmax-Pmes) )

 where: Pcor  - corrected pressure
        Pmes  - measured pressure
        Pmax  - maximum downcast pressure
        ofs dn - downcast pressure offset
        ofs dn - upcast pressure offset

Summary of CTD and thermometric pressure comparison can be found in Table 6.


C.2.3.6 HYDROZOND-6000 TEMPERATURE CALIBRATION

The CTD temperatures were calibrated against the DSRT measurements using the 3-
order polynomial.  The time drift of the CTD sensor was detected and taken care 
of by applying a linear correction.  Summary of CTD and thermometric temperature 
comparison can be found in Table 6.


C.2.3.7 NBIS MARK-3B AND HYDROZOND-6000 CONDUCTIVITY CALIBRATION

The Hydrozond-6000 CTD conductivity measurements were calibrated against the 
Autosal bottle conductivity measurements using the 3-order polynomial.

For NBIS Mark-3B the second order polynomial has been used.  The both CTD 
conductivities were corrected for station and pressure dependence.

Summary of CTD and bottle salinities comparison can be found in Tables 5 and 6.


TABLE 5: Bottle vs NBIS Mark-3B CTD statistical summary.

                      pressure         Mean      Standard   #values
       Parameter    range (dbar)    difference   deviation  in mean
       -----------  -------------   ----------   ---------  -------
                    all pressures    -0.07822     4.03609       23 
       Pressure     press < 1500     -0.95554     5.45300        9 
                    press > 1500      0.48477     2.89719       14 

                    all pressures    -0.00040     0.00577       26 
       Temperature  press < 1500     -0.00069     0.00664       12 
                    press > 1500     -0.00016     0.00514       14 

                    all pressures    -0.00022     0.00307      471 
       Salinity     press < 1500      0.00045     0.00377      220 
                    press > 1500     -0.00081     0.00213      251 


TABLE 6: Bottle vs Hydrozond-6000 CTD statistical summary.

                      pressure         Mean      Standard   #values
       Parameter    range (dbar)    difference   deviation  in mean
       -----------  -------------   ----------   ---------  -------
                    all pressures    -0.45583    13.87512      120 
       Pressure     press < 1500      2.94694     9.30399       49 
                    press > 1500     -2.80423    15.94445       71 

                    all pressures    -0.00053     0.00943      103 
       Temperature  press < 1500     -0.00251     0.01110       28 
                    press > 1500      0.00021     0.00859       75 

                    all pressures     0.00036     0.00981     1756 
       Salinity     press < 1500      0.00050     0.00997      832 
                    press > 1500      0.00013     0.00966      924 


C.3  CTD PROCESSING

C.3.1  NBIS MARK-3B PROCESSING

The NBIS Mark-3B station records were processed by procedures adopted in BSH, 
Germany.

 o the pressure offset (on deck the pressure sensor readings) is subtracted 
   from the record.
 o starting cycles corresponding to time period of conductivity sensor 
   adaptations to water conditions are eliminated from the record
 o pressure records are smoothed by Bezier cubic splines in order to digitize 
   pressure beyond the sensor resolution and to evaluate the package speed
 o time lag correction is applied to pressure and conductivity due to inertion 
   of the PRT sensor.  The time lag was determined by deriving the least 
   spiking salinity profile.
 o cycles corresponding to CTD upward or extreme movements (less are than 0.4 
   dbar/sec and greater than 2.5 dbar/sec) are eliminated
 o temperature and conductivity are twice subjected to median filter (window 31)
 o temperature and conductivity are subjected to running mean filter (window 21)
 o 2 dbar averaging is performed in accordance to the scheme suggested by R. 
   Millard and Keqi Yang (1992).


C.3.2 HYDROZOND-6000 PROCESSING

The routines applied to HydrozondÄ6000 CTD data were based on traditional 
procedures of signal digital processing adopted for specific features of the 
measuring device.

The peculiarity of the Hydrozond-6000 is the three pressure sensors working at 
different pressure ranges.  The sensors differ by sensitivity and as a 
consequence, they are characterized by different spectral structure of the 
"noise" and different "signal" to "noise" ratio.  That instantly leads to a 
necessity of independent treatment of each sensor record and smooth merge of the 
records.

So, at the first stage the segments of the records corresponding to each sensor 
were detected.  Within the each segment the spike 2.5 standard deviation control 
against the local second order polynomial was performed for all measured 
parameters.

The noise elimination was done by a running mean filter, with utilization of 
second order polynomial values as weights.  The filter windows were 21,51,121 
for consequent pressure sensor and 21 for both temperature and salinity sensors.  
Application of the polynomial has a good advantage compared to usual equal 
weighted running mean filters.  It allows us to consider the evident temporal 
trends of parameters.  To avoid the energy "alias-ing", that is common for the 
running mean filters, the second filter run has been done, with changed window, 
which was chosen as 3/4 of the initial.

This changes the frequency characteristic of the filter in such a manner, that 
now the extremes match the zeroes of a first run filter.

The rest of the processing was in an agreement with R. Millard and K. Yang 
(1992).  10 dbar averaging has been selected to maintain statistics within the 
averaging bin, considering the sampling rate of 4Hz.


C.4 GENERAL COMMENTS/PROBLEMS

The temperatures measured by CTD are all in ITS-68.

On station 5, the sounding was performed with unremoved cover of the 
conductivity sensor.  The station was repeated at the same location (station 6).  
At stations 23, 24, 25, 26, 27, 28, 29, 30, 31 artificial staircases were 
detected at depth 1200 - 2000 db.  For these data digital smoothing polynomial 
filter of 2-order was applied.

On several stations conductivity sensor of Hydrozond-6000 didn't perform well.  
This was detected by TS relation analyses and comparison with historical data 
(RV Atlantic-II, 1981 and RV Chain, 1959).  For these reasons data from stations 
70 and 71 was rejected completely.  Observations at station 55 in 981-1350 dbar 
layer were omitted, as well as the observations at station 69 in a layer from 
the surface to 3570 level.  Near bottom records at stations 32, 38, 62, 84, 121 
were eliminated due to same argumentation.

Some suspicions exist concerning the observations in 2000 - 2300 dbar layer of 
station 101, although the data is reported.

Special caution must be attributed to all the Hydrozond-6000 data in the deep 
layers. Some low-scale salinity variations were spotted in almost all the 
profiles.  The origin of these fluctuations are still under consideration, so no 
corrections were applied to the data.  Therefore it must be kept in mind that 
the data must be expertly treated in accordance with the specific individual 
research goals.


C.5  MEASUREMENT TECHNIQUES AND CALIBRATION

C.5.1. Salinity Analyses
       (S. Dobroluybov / Moscow State University).


EQUIPMENT AND TECHNIQUE

The water sample salinity were measured with a Guildline Autosal Model 8400A 
salinometer N54403 that was standardized daily (usually twice) with IAPSO 
Standard Sea Water Batch 115.  The last calibration of the salinometer was 
carried out by Guildline representation on May 1991.  All measurements, initial 
quality control and shipboard data-processing were performed by S. Dobroliubov 
(Moscow State University).  A total of 3094 water samples from 132 stations 
(mean value - more than 23 samples per each) were analyzed for salinity 
including 80 replicates.

SAMPLING PROCEDURE

Salinity samples were collected strictly according to WHP Manual (Stalcup, 
1991).  BSH silicate-glass sample bottles with a capacity of 200 ml and separate 
cones for sealing the caps were thoroughly rinsed three times, filled to the 
shoulders, dried and moved to the laboratory with controlled temperature.  Time 
lag between sampling and analysis usually varied from 4 to 20 hours, but 
sometimes it was decreased to 2-3 hours by immersing the sample bottles to the 
water bath.  The number of samples exceeded analyzed ones on 520 bottles 
transported to BSH, Hamburg for Autosal intercalibration purposes.

SAMPLE MEASUREMENTS

Salinometer laboratory was the best temperature controlled room onboard though 
this control wasn't automatic.  Nevertheless attempts to maintain the constant 
temperature during the section operation (24.09-25.10.1993) were successful with 
one exception 12.10 when air conditioning was remounted.  Laboratory temperature 
during salinometer operation ranged mainly between 26.0 and 27.3°C with mean 
value 26.8°C and standard deviation 0.5°C.

The published accuracy of the 8400A salinometer according to Operating Manual is 
0.003 psu.  But if measurements are made in a laboratory with quasi-constant 
temperature (+1°C) it should be possible to reach the precision better than 
0.001 psu.  All the procedures to attain highest accuracy described in the 
Operating Manual (section 6.5) were performed.  Only twice the shift between the 
two daily standardizations exceeded 0.001 psu at the time of lowest and highest 
laboratory temperatures. Mean difference between standardizations was 0.0004 
psu.  This shifts linearly interpolated between the first and the last sample 
readings.

All the samples were measured with Autosal bath temperature 27°C.  The 
salinometer readings were inverted to salinity in accordance with Guildline 
Operational Manual formula and Practical Salinity Scale-1978.

DATA QUALITY CONTROL

Control operations contained four parts.  The first one - Autosal calibration 
control that performed weekly with a simple suppression switch check described 
by Stalcup (1987).  This check showed absence of any discontinuities. Full 
calibration procedure was not completed during the cruise.

Another type of data control consisted of replicate analysis.  21 pairs of 
samples were collected from the same 1.8 l Niskin bottles at different stations.  
Module mean difference between the salinities of these pairs was 0.0007 psu with 
standard deviation 0.0006 psu.  The same procedure was promoted with Gydrozond 
1.2 l bottles.  59 replicates were collected including two calibration casts and 
its analysis revealed module mean salinity difference of 0.0009 psu with 
standard deviation 0.0007 psu.  From this point of view the difference in 
measurement accuracy with both types of bottles was considered to be 
statistically indistinguishable.

The third type of quality control included plotting scatter potential 
temperature-salinity diagrams and comparisons with historical data from 
International Geophysical Year and Long Lines 36°N sections.  All measurements 
sharply deviated from the subsequent climatic mean deepwater trend were assigned 
low quality flags.

In order to intercalibrate salinity measurements 520 sample bottles were 
collected and carried to BSH, Hamburg.  These samples were randomly distributed 
below 2000 m.  Such procedures allow checking Autosal calibration by indirect 
method.


REFERENCES

Guildline Instruments, 1984. Operating and Technical Manual for 'Autosal' 
   Laboratory Salinometer Model 8400 A.
Stalcup M.C.,1991. Salinity Measurements. WHP Operations and Manuals. WOCE 
   Office.


D.   Bottle Data
D.1  OXYGEN ANALYSIS
     (Ev. Yakushev and S. Borodkin)
     P.P. Shirshov Institute of Oceanology Russian Academy of Science

The dissolved oxygen analysis was performed by analysts from P.P. Shirshov 
Institute of Oceanology, Moscow (IORAN) following the Winkler method.  The 
procedures for the calibration of volumetric glassware, for the preparation of 
reagents and for water sampling was similar to corresponding IORAN technique 
(Chernyakova, 1991).  The procedure for calculations of oxygen concentrations 
based on whole bottle formulas considering the oxygen pickling temperature 
presented in WHPO publication (Culberson, 1991).  The parallel measurements of 
the oxygen concentrations with reagents prepared by Culberson and Chernyakova 
technique hadn't shown the significant differences.  Therefore the IORAN 
technique of reagent preparation was accepted.  The sampling procedure hadn't 
differences in both modifications.


EQUIPMENT AND TECHNIQUE

Reagents

The manganese chloride reagent was prepared by dissolving 500 g of analytical 
grade MnCl2 x 4H2O in 600 ml of distilled water. This solution was filtered 
through the paper filter and made up to 1 liter. The alkaline iodate reagent was 
prepared by dissolving 700 g of analytical grade KOH in 700 ml of distilled 
water. If necessary, the solution was filtered. 300 grams of KI were separately 
dissolved in 450 ml of distilled water. Both solutions were mixed together. The 
solutions of MnCl2 and KOH/KI reagents were stored in the laboratory. Small 
portions of these reagents were added before the stations to the plastic bottles 
were taken on deck. The sulfuric acid (20%) solution was prepared by adding of 
one volume of analytical grade H2SO4 (density 1.84 g/cm3) to four volumes of 
distilled water. 0.02N sodium thiosulfate was prepared by dissolving of 25.0 g 
of Na2S2O3 x 5H2O in 5 liter of fresh prepared distilled water. The starch 
solution (0.5 %) was prepared by adding 0.5 g of soluble starch to 100 ml of 
boiling distilled water. Then the solution was boiled for a minute. The reagent 
blank was determined according to the following procedure. Two ml of sulfuric 
acid, 1 ml of KI/KOH and 1 ml of manganese chloride solutions were added to 96 
ml of distilled water and thoroughly stirred after each addition. After the 
addition of 1 ml of starch solution a blue color didn't appear in all cases 
during the cruise. The titration was not necessary, and the value of blank 
accepted was equal to 0.

INSTRUMENTS

The oxygen flasks with capacity between 90-140 ml were weight calibrated with 
accuracy of 0.01 ml in IORAN hydrochemical laboratory (Moscow).  A 10 ml weight 
calibrated automatic burette with scale division every 0.02 ml was used to 
dispense the thiosulfate.  The burette constant errors changed in different 
ranges from 0.63 ml to 9.54 ml from -0.01 ml to + 0.04 ml.  A weight calibrated 
10 ml pipette (exact volume 10.00 ml) was used to dispense the potassium iodate 
solution during standardization.  The 1 ml plastic automatic reagent dispensers 
for KI/KOH and MnCl2 solutions were calibrated by dispensing 1ml ten times into 
10 ml graduated cylinder.  The calibration checked during the work several 
times.  A magnetic stirrer was used to thoroughly mix the sample during 
titration.

SAMPLING PROCEDURE

A six-inch piece of tygon tubing slipped over the outlet valve of the water 
sampler was used as the drawing tube.  The oxygen flasks were rinsed three times 
with sample water prior to filling.  The flasks were overflowed at approximately 
3 bottle volumes of sample water.  The MnCl2 and KOH/KaI reagents were added 
immediately after sampling with the dispensers.  The stoppers were carefully 
placed in the bottles to avoid the introduction of the air bubbles.  The flasks 
were carefully shaken (at least 15 energetic turns) and were stored in the 
laboratory while the precipitate settled on the bottom (about 30 minutes).  The 
temperature of the collected water was measured using a digital thermometer 
connected to the tygon tubing used for the nutrient sampling just when the 
oxygen flask was pickling.  The precipitate dissolved when 2 ml of sulfuric acid 
solution had been added.  A magnet was placed in the flask and the flask was 
placed on a magnetic stirrer.

The titration provided using 10-ml automatic burette.  The sample was titrated 
with the thiosulfate solution until it became a light straw color.  1 ml of 
starch added as an indicator and titration continued up to elimination of the 
blue solution.

CALCULATIONS OF OXYGEN CONCENTRATIONS

The procedure of calculations of the oxygen concentrations followed one 
described by Culberon (Culberson, 1991).  A corresponding Turbo C program had 
been written during the cruise.  The oxygen pickling temperature and the AUTOSAL 
salinity determination results were used for the conversion of volumetric to 
weight concentrations.


TABLE 7: Duplicate Samples Collected on Multanovskiy Cruise 40.
         Samples were collected from single Niskin bottles. The
         differences between the oxygen measurements made on these
         duplicate samples are shown. The standard deviation of the
         oxygen differences is 0.9 µmol/kg (0.0005 ml/l).

   Station  Flask       Oxy.Diff.        Station  Flask       Oxy.Diff.  
   Number   Number    ml/l  µmol/kg      Number   Number    ml/l  µmol/kg
   -------  ------    ----  -------      -------  ------    ----  -------
      4     43,17     0.03    1.2          69      1,10     0.00    0.1  
      4     15,18     0.04    1.8          69      3,12     0.01    0.6  
      4     16,19     0.00    0.2          69     24,13     0.01    0.4  
      9     10,46     0.02    0.8          69      5,14     0.02    0.7  
     10     19,46     0.02    1.0          69      6,16     0.04    1.8  
     10     20,47     0.02    0.6          69      8,17     0.05    2.4  
     15     23,24     0.04    1.5          69      9,18     0.01    0.1  
     16     23,24     0.03    1.1          72     19, 1     0.01    0.2  
     19     17,46     0.06    2.7          72     20, 2     0.01    0.2  
     19     16,47     0.03    1.6          76     22,23     0.05    1.9  
     32     15, 1     0.01    0.3          77     19,13     0.00    0.1  
     33     20, 1     0.02    1.1          77     20, 1     0.00    0.1  
     35     19, 1     0.01    0.3          80     19, 1     0.01    0.7  
     36     18, 1     0.03    1.4          80      9,10     0.02    1.1  
     39     20, 1     0.03    1.2          81     19, 1     0.00    0.2  
     40     20, 1     0.00    0.2          81     20, 2     0.01    0.1  
     41     18, 1     0.02    1.0          84     20, 1     0.01    0.3  
     44     23, 1     0.02    1.1          85     19, 1     0.00    0.3  
     45     20, 1     0.01    0.6          88     19, 1     0.01    0.5  
     49     21, 1     0.02    0.9          88     20, 2     0.00    0.1  
     50     10,22     0.02    0.8          89     19, 1     0.02    1.0  
     50      8,21     0.02    1.0          92     10, 1     0.01    0.4  
     51     10,23     0.03    1.6          95     19, 1     0.01    0.3  
     54     20, 2     0.01    0.5          98     19, 2     0.01    0.2  
     54     19, 1     0.01    0.2          98     20, 1     0.01    0.3  
     54     21,24     0.00    0.1          98      1, 1     0.00    0.0  
     55     19, 1     0.02    1.1         101     19, 1     0.00    0.2  
     58      5,12     0.04    1.9         101     20, 2     0.01    0.4  
     59     19, 2     0.00    0.1         101     21, 3     0.03    1.2  
     62      8,16     0.03    1.3         105     19, 1     0.04    1.7  
     62      7,15     0.00    0.2         105     20, 2     0.00    0.1  
     62      6,14     0.06    2.4         108     19, 1     0.02    0.9  
     62      5,13     0.01    0.4         108     20, 2     0.00    0.0  
     62     24,12     0.03    1.2         113     19, 1     0.03    0.9  
     62      2,10     0.02    0.6         113     20, 2     0.01    0.4  
     62      1, 9     0.02    1.1         114     19, 1     0.01    0.6  
     63     19, 1     0.02    0.7         114     20, 2     0.02    0.6  
     63     20, 2     0.00    0.1         119     19, 1     0.00    0.1  
     66     19, 1     0.00    0.1         119     20, 2     0.01    0.5  
     66     20, 2     0.01    0.2         120     19, 1     0.01    0.3  


CALIBRATIONS AND STANDARDS

The potassium iodate standard solution (0.020 N) was prepared using 0.7134 g of 
twice crystallized dried at 105°C analytical grade KIO3 weighted in the IORAN 
Laboratory of hydrochemistry (Moscow).  This KIO3 was dissolved and making up to 
1 liter with distilled water using in 1-liter glass volumetric flask.  The 
solution was stored in a glass bottle with ground glass stopper in the 
refrigerator.  For calibration it was prepared a solution by adding of 10.00 ml 
of potassium iodate standard solution with weight calibrated 10 ml pipette to 
approximately 80-100 ml of distilled water in an oxygen flask.  Two ml of 
sulfuric acid, 1 ml of KI/KOH and 1 ml of manganese chloride solutions were 
consequently added and the solution thoroughly stirred after each addition.  Then 
the solution was titrated with thiosulfate using automatic burette.  The 
difference between three-four parallel titer determination was during the cruise 
less then 0.02 ml.  The thiosulfate titer checked during the cruise every second 
day.  The replicate dissolved oxygen samples were collected from the single 1 
liter Niskin bottles during the cruise every day and titrated to asses the 
precision of the dissolved oxygen measurements.  Table 7 shows these results.

The standard deviations of the two tests was 0.918 µmol/kg (0.0005 ml/l) 
indicated the precision was about 0.4%.  On the first station of the voyage the 
Culberson and Chernyakova reagent preparing modifications were parallel used.  
The differences in reagent solution concentrations are shown in Table 7.  The 
soviet made REACHEM reagents used in the solution's preparation.  22 
measurements collected from separate Niskin bottles tripped at the same depth 
indicated that a difference less then 0.05 ml/l.  A very short range didn't 
allow calculation of the deviation.

COMPARISON WITH HISTORICAL DATA

To check accuracy we compared our results with the data of Atlantis-2 cruise 
(1981).  The present data set agrees with the old within our reproducibility.  
The maximum oxygen concentrations (greater than 6.5 ml/l) were observed in 
bottom layer of the western part (latitude 73°W) of the section.  The minimum 
oxygen concentrations (less than 3.3 ml/l) were observed in the oxygen minima 
layer in the western part of the section.  The obtained now picture was more 
sharp than in 1981 because the water samples were collected not in standard 
levels but in the hydrophysical extremum levels which depth determined before 
the sampling by the temperature and salinity soundings.


D.2  NUTRIENT ANALYSES
     (Ev. Yakushev and V. Konnov)
     P.P. Shirshov Institute of Oceanology Russian Academy of Science

EQUIPMENT AND TECHNIQUE

The nutrient analyses were performed by a team of analysts from P.P. Shirshov 
Institute of Oceanology (Moscow) and Arctic and Antarctic Research Institute (S-
Petersburg) using an ACE AutoAnalyzer model and KFK-3 photoelectric photometer.  
The methods for silicate acid, nitrates plus nitrite and nitrite were those 
given in AKEA manual (DATEX AKEA, 1978).  The method for phosphate was an 
adaptation of Murphy-Riley method for photometers (Modern Methods, 1992).  The 
Photometer KFK-3 (Photoelectric Photometer, 1992) was made by the Optico 
Mechanical Plant in Sergiev Posad (ZOMZ).  KFK-3 provides measurements in 
spectral diapason from 315 to 990 nm with absolute error no greater than 0.15%.  
The 100 mm cuvets were used to analyze both phosphate and nitrite.

SAMPLING PROCEDURE

Sampling for nutrients followed that for dissolved oxygen on average 15-30 
minutes after the casts were on deck.  Samples were drawn into 500 cm3 high-
density polyethylene, narrow mouse, screw-capped bottles.  Then they were 
immediately drawn into 50 ml Nessler cylinders (for phosphate and nitrite 
analyses) and introduced into the AKEA sampler (for silicate acid and nitrate 
plus nitrite analyses) by pouring into 4 cm3 polysteren cups which fit the AKEA 
sampler tray.  The 500 cm3 bottles, 50 ml Nessler cylinders and 4 cm3 cups were 
rinsed three times prior to filling.  Analyses routinely were begun within 5-15 
minutes after the 500 cm3 bottles were filled and completed within additional 
hour and a half.


PROCEDURE OF ANALYSES

PHOSPHATES

A method based on the Koroleff (Koroleff, 1972) proposals was used.  The 
produced color intensity is measured with KFK at 885 nm in a 100 mm cell.

REAGENTS.
  REACHEM reagents were used:

Molybdate reagent
  Ammonium heptamolybdate (a.g.)                     15.0 g
  Distilled water, q.s.                             500.0 ml

Sulfuric Acid
  Sulfuric acid 5 N

Antimonyl Potassium Tartrate
  Antimonyl potassium tartrate                        0.34 g
  Distilled water, q.s.                             250.0 ml

Ascorbic Acid
  Ascorbic Acid                                       5.4 g
  Distilled water, q.s.                             100.0 ml

Calibration and Standards.

Stock standard 10 000 mkg-at P /l was prepared by dissolving of
salt (1.3609 g KH2PO4) in a 1000 ml volumetric flask and diluting to
volume.  The salt was recrystalyzed, dried at 110oC and weighted in the
IORAN Laboratory of hydrochemistry (Moscow).

SILICATE.

The silicate method for AKEA utilized the method introduced by
Grasshoff based on the formation of B - 1:12 silico molybdic acid and
its partial reduction to a blue heteropoly acid. The color intensity
was measured at 880 nm with  a 20nm flow cell.

REAGENTS.
  MERCK reagents were used.

Molybdate reagent:
  Ammonium heptamolybdate (a.g.)                     10.0 g
  Sulfuric acid 5 N                                  40.0 ml
  Distilled water, silicate-free q.s.              1000.0 ml

Complexing Composition:
  Oxalic acid (a.g.)                                  7.0 g
  Sulfuric acid, conc.                               50.0 ml
  Distilled water, silicate-free q.s.              1000.0 ml

Reducing Reagent:
  Metol (p-methylaminophenol sulfate)                10.0 mg
  Anhydrous sodium sulfite                           12.0 g
  Distilled water, silicate-free q.s.              1000.0 ml
  Wetting Agent LEVOR I                               0.25 ml

Wash Solution:
  Sodium chloride (a.g.)                             20.0 g
  Distilled water q.s.                             1000.ml


CALIBRATION AND STANDARDS

Stock standard 10 000 mkg-at Si /l was prepared by dissolving of salt (0.950 g 
Na2SiF4) in a 500 ml volumetric flask and diluting to volume.  The salt was re-
crystallized, dried over concentrated sulfuric acid and weighted in the IORAN 
Laboratory of hydrochemistry (Moscow).

Working solutions, containing 1 mkg-at Si/ml were prepared with the 0.5 ml glass 
weight calibrated pipette and 500 ml weight calibrated flask.  The solutions were 
prepared in distilled water.  The apparent silicate contents were corrected for 
a salt error, which was determined separately in the beginning and the end of 
the cruise, and consisted percent.


NITRATES PLUS NITRITES

The nitrate method for AKEA utilizes the method introduced by Wood, Armstrong 
and Richards whereby nitrate is reduced to nitrite by a copper cadmium reductor 
column.  The nitrite is converted to a reddish-purple azo-dye by using 
sulfanilamide and N-1-naphthylethylendiamine dihydrochloride for the 
diazotisation.  The produced color intensity is measured at 520 nm in a 20 mm 
flowcell.


REAGENTS
  MERCK reagents were used.

Ammonium Chloride Buffer Solution:
  Ammonium chloride                                  10.0 g
  Distilled water q.s.                             1000.0 ml
  Concentrated ammonia solution
  Triton X-100, 15 % solution                         1.0 ml

Sulfanilamide:
  Sulfanilamide                                       5.0 g
  37 % Hydrochloric acid                             35.0 ml
  Distilled water, q.s.                            1000.0 ml

N-1-Naphthylethylendiamine Dihydrochloride:
  N-1-Naphthylethylendiamine dihydrochloride          0.5 g
  Distilled water, q.s.                            1000.0 ml

Wash Solution:
 Distilled water

Copper Cadmium Reductor Column:
  Copper cadmium
  Glass reductor column

Calibrations and Standards

Stock standard 10 000 mkg-at N /l was prepared by dissolving of
salt (1.0110 g KNO3) in a 1000 ml volumetric flask and diluting to
volume.  The salt was recrystalyzed, dried at 110oC and weighted in the
IORAN Laboratory of hydrochemistry (Moscow).


NITRITES.

     Nitrite is converted to a reddish-purple azo-dye by using
sulfanilamide and N-1-naphthylethylendiamine dihydrochloride for the
diazotisation.  The produced color intensity is measured with KFK at
543 nm in a 100 mm cell.


REAGENTS.
  REACHEM reagents were used.

Sulfanilac Acid:
  Sulfanic acid                                       1.0 g
  Acetic acid 12 %, q.s.                            300.0 ml

Alpfa-Naphthylamin:
  Alpha-naphthylamin                                  0.4 g
  Acetic acid 12 %, q.s.                            300.0 ml

Griss Solution:
Equal parts of Alpha-naphthylamin and sulfanic acid solutions.


CALIBRATIONS AND STANDARDS

Stock standard 10 000 mkg-at N /l was prepared by dissolving of salt (0.6910 g 
NaNO2) in a 1000 ml volumetric flask and diluting to volume.  The salt was dried 
at 110°C and weighted in the IORAN Laboratory of hydrochemistry (Moscow).

CONVERSION OF VOLUMETRIC TO WEIGHT CONCENTRATIONS

The obtained values of phosphate, silicate, nitrate and nitrite were converted 
into weight concentrations.  To calculate the seawater density there were used 
the salinity data obtained with AUTOSAL and temperature of seawater in the 
moment of the sample bottles filling (the same as at which oxygen samples were 
pickled).  The same formulas as for the oxygen conversion were used (Culberson, 
1991).

According to the recommendations of Gordon (Gordon et al, 1993) the temperature 
of the laboratory air should be used.  But it doesn't appear to be optimal: for 
silicates analysis the + 50° bath is used while the nitrate+nitrite analysis is 
provided without a bath under the plastic cover (the similar for AKEA, TECHNIKON 
and ALPKEM).  Additionally in our case phosphate and nitrites were measured 
using the 50-ml Nessler cylinders with relatively large volumes of water.

The temperature at which the samples were drawn had been accepted because water 
samples from bottles of relatively large volume (about 250 ml) were drawn into 
AKEA cups and Nessler cylinders very quickly (from 1-2 to 15-20 minutes).  The 
difference between the water samples from deep (less then 10°C) and surface (up 
to 27°C) remained even in an hour, when the phosphate samples were taken into 
photo-colorimeter.

Nevertheless the nutrient laboratory temperature was measured and results are 
given in Table 8.  The row of temperature at which oxygen was pickled is given 
in the WHP massive as an additional row.


TABLE 8: Nutrient laboratory temperatures for each station.

Stn  Date   Time  T°C    Stn  Date   Time  T°C     Stn  Date   Time  T°C 
--- ------  ----  ---    --- ------  ----  ---     --- ------  ----  ---
  3 092393  2305  22      47 100593  1100  24       91 101693  1720  25  
  4 092493  0120  21      48 100593  1535  25       92 101693  2345  25  
  6 092493  0520  21      49 100593  1945  25       93 101793  0720  25  
  7 092493  0840  22      50 100693  0015  24       94 101793  1530  25  
  8 092493  1130  22      51 100693  0445  24       95 101793  2350  25  
  9 092493  1640  22      52 100693  0920  25       96 101893  0735  25  
 10 092493  2245  23      53 100693  1345  26       97 101893  1415  25  
 11 092593  0530  23      54 100693  2030  26       98 101893  2200  25  
 12 092593  1140  22      55 100793  0235  26       99 101993  0530  24  
 13 092593  1630  22      56 100793  0940  26      100 101993  1230  24  
 14 092593  2215  22      57 100793  1530  26      101 101993  2030  24  
 15 092693  0330  22      58 100793  2130  25      102 102093  0315  23  
 16 092693  0850  22      59 100893  0350  24      103 102093  0945  23  
 17 092693  1420  22      60 100893  0850  23      104 102093  1720  23  
 18 092693  1830  22      61 100893  1415  23      105 102193  0005  23  
 19 092693  2320  22      62 100893  1925  23      106 102193  1040  24  
 20 092793  0450  22      63 100993  0415  23      107 102193  1715  24  
 21 092793  1050  22      64 100993  1030  24      108 102293  0055  24  
 22 092793  1645  23      65 100993  1645  25      109 102293  0445  24  
 23 092793  2315  22      66 100993  2325  25      110 102293  0845  25  
 24 092893  0540  22      67 101093  0615  25      111 102293  1245  25  
 25 092893  1230  22      68 101093  1230  25      112 102293  1620  24  
 26 092893  2000  23      69 101093  1925  25      113 102293  2030  23  
 27 092993  0300  23      70 101193  0100  25      114 102393  0030  22  
 28 092993  0830  22      71 101193  1200  26      115 102393  0420  22  
 29 092993  1340  23      72 101193  1855  25      116 102393  0830  22  
 30 092993  2350  22      74 101293  0715  26      117 102393  1215  22  
 31 093093  2355  23      75 101293  1315  26      118 102393  1555  22  
 32 100193  1740  23      76 101293  1955  26      119 102393  2015  22  
 33 100293  0025  23      77 101393  0230  26      120 102493  0106  22  
 34 100293  1015  23      78 101393  0835  25      121 102493  0540  22  
 35 100293  1545  23      79 101393  1445  26      122 102493  0830  22  
 36 100293  2130  23      80 101393  1935  26      123 102493  1020  22  
 37 100393  0345  23      81 101493  0100  26      124 102493  1355  22  
 38 100393  0935  23      82 101493  0740  26      125 102493  1630  22  
 39 100393  1500  24      83 101493  1345  26      126 102493  1930  22  
 40 100393  2030  24      84 101493  2040  26      127 102493  2230  22  
 41 100493  0230  24      85 101593  0325  25      128 102593  0055  22  
 42 100493  0825  24      86 101593  0940  25      129 102593  0315  22  
 43 100493  1435  24      87 101593  1545  25      130 102593  0525  22  
 44 100493  2000  24      88 101593  2230  25      131 102593  0730  22  
 45 100593  0115  24      89 101693  0455  25      132 102593  0850  22  
 46 100593  0640  24      90 101693  1120  25      133 102593  1025  22  


COMPARISON WITH WHOI STANDARD SOLUTIONS

In Woods Hole we checked our standard solutions with the WHOI ones. Dr. Zofia 
Molodzinska kindly presented the standard solutions taken into the analysis 
procedure.  The WHOI phosphate standard appeared to be 4% higher than our 
standard.  The difference between the nitrates solutions was about 3% (the WHOI 
standard was higher).  The silicate standards haven't differed at all.

The differences for phosphates and nitrates were relatively large but correspond 
to the methods accuracy.  It's a pity, the measurements were provided at sea 
after we left Woods Hole, so it was not possible to repeat them and to check the 
standard qualities.

COMPARISON WITH HISTORICAL DATA

To check accuracy we compared our results with the data of Atlantis-II cruise 
(1981).

The present data of nitrates set agrees with the old within our reproducibility.  
The concentrations reached 20 µmol/l in the bottom layers of western part and 
22-24 µmol/l in western part.  The maximum concentration (29 µmol/l) was found 
in the maximum layer at depth 935 m at latitude 71°W.  The minimum 
concentrations (0 µmol/l) observed in the surface layers.

The phosphate fields also agreed with the old ones.  The maximum concentrations 
were observed in bottom layer (1.4 µmol/l in western part and 1.6 µmol/l in 
eastern) and in the layer of maximum in the western part (1.7 µmol/l).  The 
minimum concentrations (0 µmol/l) were observed in the surface layer.

The silicate concentrations were found some greater than in 1981.  The maximum 
concentrations (greater than 50 µmol/l) were observed in the bottom layer at the 
latitude 56°W.  The concentration in the maximum layer was 24 µmol/l.  The 
minimum values (less than 1 µmol/l) were observed in the surface waters.

As for oxygen, the 1993 pattern was more contrast than 1981, because the water 
samples were collected not at standard levels but at the hydrophysical extremum 
levels which were determined during the temperature and salinity downcast 
soundings.



REFERENCES

Aminot, A. and D. Kirkwood. 1995. "Report on the results of the fifth ICES 
   intercomparison exercise for nutrients in sea water".  International Council 
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Bordovskiy, O.K., A.M. Chernyakova, Ed. "Modern methods of the ocean 
   hydrochemical investigations". P.P. Shirshov Institute of Oceanology. Moscow, 
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Chernyakova, A.M., 1992. "The Winkler method dissolved oxygen determination. 
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Culberson, C.H., 1991. "Dissolved oxygen. WHP Operations and Methods" - July 
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Koroleff, F., 1972. "Determination of dissolved inorganic phosphorus and total 
   phosphorus. Methods for sampling and analysis of physical, chemical and 
   biological parameters". Cooperative research report JCES, Series A., N29, pp. 
   44-49.
Photoelectric Photometer KFK-3. Technical description and exploitation 
   instruction. 47 pp. (In Russian).
Results of an Oxygen/Salinity Comparison Cruise in the R/V Vernadsky. WHP Office 
   Report WHPO 92-3 WOCE Report 93/92. July 1992 Woods Hole, Mass. USA, 43 pp.
Whitledge, T. E., S. C. Malloy, C. J. Patton and C. D. Wirick. 1981. "Automated 
   nutrient analysis in seawater".  Brookhaven National Laboratory, U.S. Dept. 
   of Energy and Environment, Upton, NY. 216 pp.



WHPO DATA CONSISTENCY CHECK


About the '_check.txt', '_sal.ps' and '_oxy.ps' files:

The WHP-Exchange format bottle and/or CTD data from this cruise have been
examined by a computer application for contents and consistency. The
parameters found for the files are listed, a check is made to see if all
CTD files for this cruise contain the same CTD parameters, a check is made
to see if there is a one-to-one correspondence between bottle station
numbers and CTD station numbers, a check is made to see that pressures
increase through each file for each station, and a check is made to locate
multiple casts for the same station number in the bottle data. Results of
those checks are reported in this '_check.txt' file.

When both bottle and CTD data are available, the CTD salinity data (and, if
available, CTD oxygen data) reported in the bottle data file are subtracted
from the corresponding bottle data and the differences are plotted for the
entire cruise (not available for this cruise).

Following parameters found for bottle file:

        EXPOCODE       DATE       CTDSAL         SILCAT_FLAG_W
        SECT_ID        TIME       CTDSAL_FLAG_W  NITRIT
        STNNBR         LATITUDE   SALNTY         NITRIT_FLAG_W
        CASTNO         LONGITUDE  SALNTY_FLAG_W  NO2+NO3
        SAMPNO         DEPTH      OXYGEN         NO2+NO3_FLAG_W
        BTLNBR         CTDPRS     OXYGEN_FLAG_W  PHSPHT
        BTLNBR_FLAG_W  CTDTMP     SILCAT         PHSPHT_FLAG_W
	
a03_hy1.csv -> NO2+NO3_FLAG_W found without matching parameter.

All ctd parameters match the parameters in the reference station.
  Station #11 has a CTD file, but does not exist in a03_hy1.csv.
  Station #27 has a CTD file, but does not exist in a03_hy1.csv.
  Station #31 has a CTD file, but does not exist in a03_hy1.csv.
  Station #106 exists in a03_hy1.csv, but does not have a corresponding CTD file.
  Station #107 exists in a03_hy1.csv, but does not have a corresponding CTD file.

No bottle pressure inversions found.
Bottle file pressures are increasing.

No multiple casts found in bottle data.


 

WHPO DATA PROCESSING NOTES:
      
Date      Contact       Data Type    Data Status Summary
--------  ------------  -----------  -------------------------------------------
02/28/94  Tereschenkov  SUM/DOC      Submitted On disk
      
12/11/95  Lozovatsky    CTD  Problem with CTD calibration
          2) AR13 1992, Sokov (GOIN). This cruise was not declared in the WHP, 
             as Dr. Alex Sokov said (to) me. But it is possible to include the 
             data of the cruise to the WHPO data set. The problem is the CTD 
             calibration, because the measurements were made by HYDROZOND - 
             Russian CTD. The data will also prepare by WNDC. By the way Dr. 
             Sokov is the head of the center. He left GOIN for the P.P. Shirshov 
             Institute of Oceanology. He said that it will take about 2-3 months 
             to prepare these data.
          3) A03 1993, Tereschenkov (IORAS). There is the same problem like in 
             the p.2 - the CTD calibration. Tereschenkov is finishing this 
             procedure and as he thinks the data will be prepared for 
             transmission in a two weeks.
         
01/26/96  Tereschenkov  BTL/SUM/DOC  Submitted for DQE On disk
      
03/26/96  Tereschenkov  Various      Data Clarifications
          Questions from Cindy Ruhsam/WHOI:
          1) Were there any underway measurements taken during the cruise, i.e. 
             ADCP, bathymetry that was run, Thermosalinograph and any 
             meteorological observations observed.
              * Yes, we had bathymetry observations done along the cruise track
          2) Is Nitrate N+N
              * Yes
          3) What temperature scale did you use T68 or T90 ?
              * We used the ITS-68
      
12/11/96  Tereschenkov  CTD          Submitted for DQE On disk; no CTDOXY
      
04/14/99  Kappa         DOC          Update  pdf version created
      
04/30/99  Kappa         DOC          Update  Cruise Plan added
      
04/24/00  Kappa         Cruise ID    WOCE expocode updated
          changed from RUCT40_1 to 90CT40_1
      
05/10/00  Tereschenkov  CTD/BTL      Data are Public
          By this message I would like to notify you that I have no objections 
          to make the data public. I agree the data to be distributed among the 
          oceanographic community with no restrictions. 
      
05/22/00  Huynh         DOC          Website Updated; pdf, txt versions online
      

Date      Contact       Data Type    Data Status Summary
--------  ------------  -----------  -------------------------------------------
06/08/00  Bartolacci    CTD/BTL      Website Updated; data unencrypted
          I have unencrypted the following onetime cruises:
          A03   90CT40_1:  CTD, BOT (sal, O2, and nuts only)
      
03/20/01  Diggs         CTD/BTL/SUM  Files on website Updated w/ new expocodes
          Updated expocodes in all CTD, Bottle, SUM and (ascii) DOC files 
          online. Changed expocode from RUCT40/1 to 90CT40_1
      
06/20/01  Uribe         BTL          Exchange file online
          Bottle file in exchange format has been linked  to website.
      
06/21/01  Uribe         CTD/BTL      Website updated w/ exchange files
          The exchange bottle file name in directory and index file was 
          modified to lower case.  CTD exchange files were put online.
      
12/17/01  Hajrasuliha   CTD/BTL      Internal DQE completed
          The following are results from the examminer.pl and plotter.pl code 
          that were run on this cruise. Not all of the errors are reported but 
          rather a summery of what was found. For more information you can go to 
          the cruise directory, and look at the NEW file called 
          CruiseLine_check.txt. (see "Data Consistency Check" in this doc.
            NO _oxy.ps and _sal.ps available for this cruise because of CTDOXY 
            unit missing from bottlefile.
          * A03_hy1.csv -> NO2 NO3_FLAG_W found without matching parameter.
          * Station #10 has a CTD file, but does not exist in A03_hy1.csv. 
          * Station #100 has a CTD file, but does not exist in A03_hy1.csv. 
          * Station #101 has a CTD file, but does not exist in A03_hy1.csv. 
      
12/18/01  Uribe         CTD          Website Updated w/ exchange File 
          CTD has been converted to exchange using the new code and put 
          online.
      
04/08/03  Kappa         DOC          Update
          * Added WHPO-generated "Data consistency Check"
          * Deleted redundant sections from earlier online pdf and text docs
          * Updated WHPO-generated cruise track
          * Updated internal links in pdf doc
          * Reformatted text
          * Updated these WHPO Data Processing Notes


