A.   CRUISE NARRATIVE:  A06 AND A07

A.1. HIGHLIGHTS

                         WHP CRUISE SUMMARY INFORMATION

    WOCE section designation  A07                     | A06 
----------------------------  ------------------------|------------------------
      Expedition designation  35A3CITHER1_1           | 35A3CITHER1_2 
            Chief Scientist*  ALAIN MORLIERE/ORSTOM   | CHRISTIAN COLIN/ORSTOM
                       Dates  1993.01.02 - 1993.02.10 | 1993.02.13 - 1993.03.19
                                                      | 
               Ports of call  Pointe Noire (Congo)    | Cayenne
                                JAN 2                 |   FEB 13
                              Natal (Brazil)          | Abidjan (Ivory Coast)
                                JAN 23                |   MAR 08
                              Cayenne (French Guiana) | Pointe Noire
                                FEB 10                |   MAR 19
                                                      | 
                                     7° 30.09'N       |      8° 1.95'N
       Geographic boundaries  35°8.02'W    10°50.39'E | 51°19.5W    3°48.59'W
                                     4° 47.94'S       |      4° 0.02'S

                         Ship  L'ATALANTE
           Number of stations  224 (total, both legs)
     Floats/drifters deployed  none
  Moorings deployed/recovered  none
         Contributing Authors  T. Müller; A. Billant, M. Arhan 
_______________________________________________________________________________

*Chief Scientists and their affiliations:

                                ALAIN MORLIERE
Institut Français de Recherche Scientifique pour le Developpement en Cooperation 
                                   (ORSTOM)
  currently at: Universite Pierre et Marie Curie (Paris 6) ~ Tour 14 2eme Etage 
                                 4 Place Jussieu
             Paris Cedex 05, 75252 ~ FRANCE ~ FAX: 33-1-44-27-3805

                                CHRISTIAN COLIN
Institut Français de Recherche Scientifique pour le Developpement en Cooperation 
                                   (ORSTOM)
              P.O. Box 165 ~ Cayenne Cedex, 97323 ~ FRENCH GUIANA 
                      TEL: 594-302-785 ~ FAX: 594-319-855
_______________________________________________________________________________



CRUISE SUMMARY

Cruise Track and station locations are shown in PDF doc


SCIENTIFIC GOALS

An important question, which directly influences the climate changes, is the 
northward redistribution of the excess of heat flux gained at the low 
latitudes. The Atlantic ocean is unique compared to the Pacific and Indian 
Oceans because it receives heat from these two oceans. The northward heat 
transport is large according to the 3D-model of Philander and Pacanovski 
(1986). It mainly crosses the equator along the western boundary, and because 
of the size of the equatorial Atlantic belt it is easier for the observation.

Intensive studies of the surface circulation devoted to the tropical Atlantic 
ocean took place few years ago through international or national experiments: 
GATE (1974), FGGE (1979), recently FOCAL/SEQUAL (1983-1984) and TOGA (since 
1985). At the present time, STACS/NOE programme, carried out in the western 
area, leads to a better description (time and space scales) of the intermediate 
and deep circulation along the western boundary However the estimation of mass 
and heat inter-hemispheric transports requires transects of hydrography and 
geochemical tracers observations over the entire equatorial area, from the sea 
surface to the bottom, in order to characterize (qualitatively and 
quantitatively) the water masses, which are involved in the cross-equatorial 
fluxes of mass and heat.

Among all the water masses, the North Atlantic Deep Water is the main component 
of the "cold water" system of the global oceanic circulation, according to the 
thermocline circulation cell associated with NADW production (Gordon, 1996). 
This water mass, issued from the two northern sites (Labrador Sea and Greenland 
Sea - Norwegian Sea overflow), spreads to the south, between 1000 and 4000 in 
depth in connection with the deep western boundary current. A large part of 
this water mass crosses the equator and flows on along the south American 
shelf, but tracer distributions (oxygen, nutrients, freons) suggest an eastward 
spreading of NADW along the equator. There must be a compensating flow of upper 
layer moving northward to compensate NADW production. According to Gordon 
(1996), this continuity is accomplished primarily within the ocean warm water 
thermocline layer (Pacific to Indian flow within Indonesian Seas, then entry 
into South Atlantic by Agulhas Current), the Pacific to Atlantic transport of 
Subantarctic water ("cold water route") through the Drake Passage being 
considered of secondary importance. The information on the cross-equatorial 
fluxes of all these water masses are easy to be computed in the equatorial 
Atlantic ocean.

Knowledge on the intermediary and deep circulation in this part of the ocean 
are drawn from German cruise (Wüst, 1935), IGY cruise (1958) and American 
cruises (GEOSECS, 1972 - TTO and AJAX, 1983 - SAVE, 1986-1987). The network of 
stations (hydrography and small volume tracers) planned in the CITHER I cruise 
will be denser (on the average 30 nautical miles between stations along the 
sections) than the previous ones (100 nm during SAVE).


The CITHER I cruise has several objectives:

~ a better description of the oceanic circulation in the equatorial belt (7°30 
  N - 5' S), from the surface to the bottom: how the cross-equatorial exchange 
  is concentrated in the western part ?

~ a better understanding of the basic processes of the circulation, mainly the 
  thermohaline component: how the equatorial circulation, mainly zonal, is 
  connected to the north and south subtropical gyres ?

~ a better estimation of the mass and heat meridional transports: what are the 
  relative contributions of the intermediate and deep layers of the ocean to the 
  cross-equatorial exchange of mass and heat ?


To fulfil these objectives , two approaches have been retained:

The first one, analytical, will consist of the description of the hydrographic 
structure: 
                           (temperature - salinity)

reinforced by geochemical tracer measurements: 

              (oxygen -nutrients - freons - tritium/helium - C02)

of the different water masses:

         (South Atlantic Central Water - Antarctic Intermediate Water -
              North Atlantic Deep Water - Antarctic Bottom Water)


The second one, global, will consist in determining the absolute mass and heat 
transports by means of inversion methods with tracers and a few direct current 
measurements (ADCP - PEGASUS profiles) as constraints.

One main goal of WOCE is to develop models for predicting climate changes; we 
need more data to validate these models. The WOCE Implementation Plan 
recommends cooperation with associated C02 programmes in order to extend the 
measurements of the oceanic uptake of C02. Twenty years after GEOSECS (1972), 
ten years after FOCAL (1982-1984) and TTO/TAS (1983), the CITHER I cruise will 
give one more time the opportunity to measure the atmospheric and oceanic 
fields of C02 partial pressure.


SAMPLING ACCOMPLISHED

Water sampling on the cruise included measurements of salinity both by CTD and 
water bottle samples, CTD and bottle sample oxygen determinations, CTD 
temperature, and nutrients (silicate, phosphate, nitrate, nitrite).  Tracer 
analyses were made for CFC-11 and CFC-12 as well as sampling for 
tritium/helium.

Besides water sampling was made for measurements of CO2 system parameters (TCO2, 
pH, fugacity of CO2), dissolved gases (nitrogen, argon, methane and nitrous 
oxide).


TYPE AND NUMBER OF STATIONS

During the two legs of the cruise a total of 224 CTDO/Rosette stations were 
occupied using a 32-bottle IFREMER rosette equipped with 8 liters PVC water 
sampling bottles.

The usual spacing of stations was 30 nm, except over the continental slope (4 
to 5 nm) and the abyssal plains (40 nm).


LIST OF PRINCIPAL INVESTIGATORS

The parameters with the principal investigators and their affiliation are 
listed in Table 1.


Table 1:  List of measured parameters and the Principal Investigators for each.

PARAMETERS                SAMPLING GROUP       PRINCIPAL INVESTIGATOR
------------------------  -------------------  ----------------------
CTDO2 / Rosette           LPO/IFREMER-Brest    M. Arhan / H. Mercier
S, O2                     LPO/IFREMER-Brest    M. Arhan / H. Mercier
NO3, NO2, PO4, Si(OH)4    ORSTOM-Brest         C. Oudot
                          LOC/UBO-Brest        P. Morin
CFC-11, CFC-12            ORSTOM/LODYC-Paris   C. Andrie
Tritium, Helium           LMCE-Saclay          P. Jean-Baptiste
CO2 system                ORSTOM-Brest         C. Oudot
Dissolved gases (N2, Ar)  ORSTOM-Brest         C. Oudot
Trace gases (N2O, CH4)    LOC/UBO-Brest        M. Guevel
ADCP                      ORSTOM/LODYC-Paris   A. Morliere
                          LPO/IFREMER-Brest    H. Mercier
PEGASUS                   IfM-Kiel             F. Schott
                          ORSTOM-Cayenne       C. Colin


PRELIMINARY RESULTS

The R/V L'ATALANTE departed Pointe Noire, Congo for the WHP Section A7 on 
January 2nd, 1993.  The first station near 5°04 N, 10°40 E (bottom depth = 2100 
m) was to test one of the two CTD systems and its rosette water sampling 
equipment.  The CTDs are EG&G Neil Brown Mark III equipped with Beckman 
dissolved oxygen sensor.  The first CTD equipment was replaced by the second 
one at station 83 (January 29, 1993) owing to problems with the conductivity 
sensor.  All the CTD temperature, pressure and conductivity sensors were 
calibrated at the IFREMER calibration facility both before and after the 
cruise.  The conductivity and oxygen sensors were also calibrated at sea using 
data from the analyses of the salinity and oxygen samples collected at each 
station.  Water samples were collected from 32 PVC sampler bottles (capacity 8 
liters)) mounted on the two-storied IFREMER Rosette sampler.  The water sample 
conductivity measurements and oxygen titrations were made in a constant 
temperature (20°C) portable laboratory.

Additional samples were also collected from each PVC bottle for the shipboard 
analysis of nutrients (silicate, phosphate, nitrate, nitrite) and 
chlorofluorocarbons CFC-11 and CFC-12 (every other station until station number 
66, every station beyond and until the last station).  Helium and tritium 
samples were also collected at many of the stations (a total of 58): the 
analysis of these samples will be later carried out in a shore-based 
laboratory.

Other samples were also collected from PVC bottles for the shipboard analysis 
of dissolved gases (nitrogen - argon - total CO2 - methane and nitrous oxide) 
and the determination of pH and fugacity of CO2 (in surface water and in 
atmosphere).  The phytoplankton biomass (chlorophyll) was also sampled for 
shore-based analysis.

Underway ADCP and thermosalinograph data were recorded along the track of the 
ship (10 154 nm).  Twelve PEGASUS profilings were done near the western coast 
in the boundary currents.


PROBLEMS

During the first leg (station number 83) we must have to replace the CTD 
system: shift and noises of the conductivity sensor.  The second CTD system 
will be used until the end of the cruise without problems.

Through the CRUISE we used successively three Guildline salinometers: one 
Autosal and two Portasal.  The problems were a shift of the calibration between 
the stations; or drift within a series of measurements.  The later acquired 
Portasal model has given the best results and was used to measure all the 
salinities during the leg 2.

With the analytical measurements of the tracers, the most serious problem was 
the CFC contamination from the PVC sampling bottles, mainly due to the grease 
of the stopcocks.  A few special stations (5) were made to test the 
contamination's, by closing all the bottles at the same depth where the CFC 
concentrations were the lowest (generally around 2500 m depth).  The mean 
contamination is estimated to about 0.005 ± 0.002 pmol/l for F-12 and to about 
0.008 ± 0.002 pmol/l for F-11.


STATION SUMMARY

The station positions, time, etc are tabulated in a summary file.  This file 
(CITHER1.SUM) is reported on attached pages (numbered 1 to 12) and on attached 
floppy disk in MS-DOS format (ASCII characters).

The parameter numbers are defined in Table 3.


TABLE 2:  Cruise participants

Participants            Role                      Affiliation            Leg
----------------------  ------------------------  -------------------  -------  
Chantal Andrie          CFCs                      ORSTOM/LODYC-Paris   1     2
Michel Arhan            CTDO2                     LPO/IFREMER-Brest    1     
Sabine Arnault          Tritium, Helium           ORSTOM/LODYC-Paris         2
François Baurand        Nutrients                 ORSTOM-Brest         1     2
Andre Billant           S, O2                     LPO/IFREMER-Brest          2
Jean-Michel Bore        CTDO2                     ORSTOM-Cayenne       1     2
Bernard Bourles         CTDO2                     ORSTOM-Cayenne       1     2
Pierre Branellec        S, O2                     LPO/IFREMER-Brest    1     
Elisabete Braga         Oxygen                    IOUSP-Sao Paulo            2
Remy Chuchla            Oxygen                    ORSTOM-Cayenne       1     
Souleymane Cissoko      CTDO2                     CRO-Abidjan                2
Christian Colin         Chief Scientist, Pegasus  ORSTOM-Cayenne             2
Daniel Corre            CTDO2                     ORSTOM-Brest               2
François Dangu          Salinity - CTDO2          ORSTOM-Cayenne       1     2
Nathalie Daniault       CTDO2                     LPO/IFREMER-Brest    1     
Andre Dapoigny          Tritium, Helium           LMCE/CEN-Saclay      1     
Alain Dessier           CO2, N2, Ar               ORSTOM-Brest               2
Jean-Pierre Girardot    CTDO2                     LPO/IFREMER-Brest          2
Jean-Pierre Gouillou    CTDO2                     LPO/IFREMER-Brest    1     
Yves Gouriou            CTDO2                     ORSTOM-Brest         1     2
Stephanie Gueneley      Nutrients                 ORSTOM-Brest         1     
Mickael Guevel          Trace gases               LOC/UBO-Brest        1     2

Participants            Role                      Affiliation            Leg
----------------------  ------------------------  -------------------  -------
Catherine Hemon         CTDO2                     LPO/IFREMER-Brest          2
Philippe Hisard         Salinity                  ORSTOM-Brest               2
Philippe Jean-Baptiste  Tritium, Helium           LMCE/CEN-Saclay            2
Milton Kampel           CTDO2                     INPE-Brazil          1     
Lamine Keita            CTDO2                     CERESCOR-Conakry           2
Jean-Jacques Lechauve   CTDO2                     ORSTOM-Brest         1     
Jerome Lecomte          CO2, N2, Ar               ORSTOM-Cayenne       1     2
Nathalie Lefevre        CO2 Fugacity              LODYC-Paris                2
Jean-François Maguer    Nutrients                 LOC/UBO-Brest        1     
Jean-François Makaya    CTDO2                     ORSTOM-Pte Noire     1     
Laurent Memery          CFCs                      LODYC-Paris          1     
Herle Mercier           CTDO2, ADCP               LPO/IFREMER-Brest          2
Marie-Jose Messias      CFCs                      LODYC-Paris                2
Pascal Morin            Nutrients                 LOC/UBO-Brest              2
Alain Morliere          Chief scientist, ADCP     ORSTOM/LODYC-Paris   1        
Claude Oudot            CO2, N2, Ar               ORSTOM-Brest         1     2
Christophe Peignon      CO2, N2, Ar               ORSTOM-Lome          1     
Jean-Paul Rebert        Tritium, Helium           ORSTOM-Brest         1     
Joerg Reppin            Pegasus                   IFM-Kiel             1     
Birane Samb             CTDO2                     CRO-Dakar                  2
Jean-François Ternon    CFCs                      ORSTOM-Brest         1     2
Mohideen Wafar          Nutrients                 LOC/UBO-Brest        1     


TABLE 3:  Parameter numbers in the CITHER1.SUM file

       
            WOCE PARAMETER             
            No.    Name                          Mnemonic   Units
            --     ----------------------------  ---------  -------------
             1     Salinity                      SALNTY     PSS-78
             2     Oxygen                        OXYGEN     µmol/kg
             3     Silicate                      SILCAT     µmol/kg
             4     Nitrate                       NITRAT     µmol/kg
             5     Nitrite                       NITRIT     µmol/kg
             6     Phosphate                     PHSPHT     µmol/kg
             7     Freon-11                      CFC-11     pmol/kg
             8     Freon-12                      CFC-12     pmol/kg
             9     Tritium                       TRITUM     Tritium units
            10     Helium                        HELIUM     nmol/kg
            11     Helium                        DELHE3     %
                           
            15     Argon                         ARGON      nmol/kg
                           
            23     Total carbon                  TCARBN     µmol/kg
            24     Total alkalinity              ALKALI     µmol/kg
            25     Partial pressure of CO2       PCO2       µatm
            26     pH                            pH         none
                           
            31     Methane                       CH4        nmol/kg
            32     Nitrogen (dissolved organic)  DON        µumol/kg
            33     Nitrous oxide                 N2O        nmol/kg
            34     Chlorophyll a                 CHLORA     µg/kg
            35     Phaeophytin                   PPHYTN     µg/kg





DATA QUALITY EXPERT (DQE) REPORT ON CTD O2 DATA
(Thomas J. Müller*)
02 Oct, 1996                                           *Institut für Meereskunde
                                                         an der Universität Kiel
                                                          Duesternbrooker Weg 20
                                                             24105 KIEL, Germany
                                                e-mail: tmueller@ifm.uni-kiel.de

INTRODUCTION

The French written cruise report consists of four volumes:
Volume  1 with general cruise information.  Also, procedures of calibration and 
          processing of 'En Route' data, ship borne ADCP, and some PEGASUS 
          stations are described. 
Volume  2 (Le Groupe CITHER-1, 1994) with a description of CTD-O2 data 
          calibration, processing and extensive hard copy displays. 
Volumes 3 and 4 with geochemical measurements.

Also, an English written cruise report is available at the WHPO (6 pages plus -
.SUM file--above).

The present DQE report deals with the CTD-O2 data from A6 and A7.  It consists 
of three parts:

(A) A brief summary of the French written A6/A7 CTD-O2 data report (Le Groupe 
    CITHER-1, 1994; GC1 henceforth) which describes the procedures of 
    laboratory calibrations, data acquisition and processing, in-situ 
    calibrations and verifications. Along with this summary, I have included 
    (and flagged as such) some comments at the end of sections where 
    appropriate. No figures and tables are available in electronic form from 
    the above report, and therefore reference is made to figures and tables as 
    they appear in the report.
(B) A report of evaluation of the A6 and A7 CTD-O2 data as they were available 
    at the WHP-O in September 1996. 
(C) Recommendations


PART A.

Campagne CITHER-1 of R/V L'ATALANTE 
(2 janvier-19 mars 1993). 
Recueil de donnees, 
Volume 2: CTD-O2

(English summary by DQE with comments added at ends of sections; sections, 
figures and tables are numbered as in the French report)


  I  THE CITHER-1 GROUP
     To obtain WOCE one time zonal sections A6 (along 07N30') and A7 (04S30') is 
     one among other French contributions to WOCE.  The cruise in 1993 was 
     divided into two legs.  In addition to stations along A6 and A7, two 
     meridional sections were obtained between A6 and A7, along 035šW and 004šW. 

     PI's for CTD-O2/rosette were Michel Arhan (leg 1) and 
                                 Herle Mercier (leg 2); 
     see Table 1 in the report for other PI's.


 II  CRUISE PARTICIPANTS WITH RESPECT TO CTD-O2 WORK
     see Table 2


III  CALIBRATION OF CTD-O2 MEASUREMENTS
     (A. Billant and P. Branellec, LPO)

1. ACQUISITION OF CTD-O2 DATA
   A total of 223 stations with two Mark III CTD-O2 systems were obtained along 
   with a 36x8 l bottle rosette PASH 6000 developed by LPO.  For locations of 
   stations 

   see Figure 1.


MAJOR EVENTS
 
(i)   Section A7 was interrupted westbound after Stat. 77 before the vessel 
      entered the 200 nm EEZ of Brazil.  Prior to continuing A7, L'ATALANTE had 
      to call port of Natal, Brazil, to pick up a Brazilian observer.  Five 
      days later, A7 was continued with Stat. 78 as repeat station on the 
      position of Sta. 77.
(ii)  The first CTD-O2, S/N 2521, was replaced due to problems with the 
      conductivity sensor after Stat. 82 by the second CTD-O2, S/N 2782.
(iii) Stations 27, 75, 118 and 190 were taken in between WHP stations, with 
      bottle being closed at special depths for calibration and test purposes.


DATA ACQUISITION AND PROCESSING

The CTD's data cycles were transferred to the computer at a 32 Hz rate and on-
line processed.  Processed data then were stored on magnetic tape.  Two steps 
of processing were applied.  First, each data value was compared with the one 
in the preceding cycle.  If the absolute difference of a value to the preceding 
one exceeded a certain amount (see table below), the complete cycle was 
omitted.  The parameters for this comparison were:

            Pressure      0.5   dbar
            Temperature   0.032 K for pressure < 1500 dbar
                          0.005 K for pressure > 1500 dbar
            Conductivity  0.032 mS/cm for pressure < 1500 dbar
                          0.005 mS/cm for pressure > 1500 dbar
            Oxygen curr.  0.010 UA 
            Oxygen temp.  0.3   K

Next, cycles were averaged in pressure intervals.  The intervals were chosen 
such that of all data cycles at least 25% were kept as 'good' and contribute to 
the average.  For a lowering speed of 1 m/s, this means that at least 8 cycles 
contribute to an average over 1 dbar.

Only, lowering profiles are considered.


DQE'S COMMENTS ON SECTION 1:

From the French report, I understand that the original data set is not stored 
but only the (single value) de-spiked and averaged cycles with no other 
processing steps being applied before or afterwards.  If this is true, I see 
some principal problems with this procedure.  Although such a procedure may not 
affect very much CTDs that behave well, and although the non-averaged data may 
not be available any longer (as I understand the report), let me describe some 
steps necessary in processing open sensor CTD data.

(i)  the de-spiking method as described above can only recognize single spikes. 
     It also is problematic in that it compares only with preceding values.  If 
     two or more spikes occur in turn (which to my experience may happen) these 
     are smeared into the average during the averaging process; they can never 
     be re-identified, and it is hard to detect and remove such 'bad' averages.
(ii) Before averaging or low pass filtering, other important processing steps 
     are performed for 'open sensor' CTD's by other institutes like WHOI (see 
     Yang and Millard, 199xx) and IfM Kiel.  They are not described for A6 and 
     A7.  

     The steps are:

~ create (if not already available) a cycle number or time and keep it 
  throughout the processing.
~ check the (single value) despiked series for further spikes.
~ apply a low pass filter to the pressure series; this matches the 
  pressure sensor resolution (0.1 dbar) to the lowering speed which at 1 
  m/s requires a resolution of 0.03 dbar.
~ monotonize the profile with respect to pressure; conductivity and 
  oxygen sensor respond quite differently under different lowering 
  speeds.  Even better would be to first apply a 'minimum lowering 
  speed' criterion to the profile and then monotonizing.
~ match the time constants of the (combined) temperature signal and the 
  conductivity sensor.  This can be done either 'by eye' looking at 
  salinity spikes in sharp gradient regions, or more objectively by 
  looking at the coherence and phase spectra.
~ apply a low pass filter to 0.5 dbar response and average on 0.5 dbar 
  intervals.
~ apply the (static) calibrations for pressure, temperature and 
  conductivity.
~ apply a low pass filter to 2 dbar response.
~ apply the correction for the dynamic response of the pressure sensor 
  to temperature changes
~ average on 2 dbar intervals
~ calculate follow up quantities (salinity, pot. temperature, pot. 
  density)
~ apply the calibration of the oxygen sensor.


2. Sampling

Sampling was done with a 36 x 8 l bottle rosette PASH 6000 developed by LPO.  
Bottles were closed on the way up (see Fig. 2, 3).  A total of 6269 samples for 
salinity and 6460 samples of analysis of dissolved oxygen were taken.  12 
bottles carried reversing temperature and pressure sensors made by SIS.  
Samples from bottles were drawn according to the instructions in the WOCE 
operation manual.


DQE'S COMMENT ON SECTION 2

ok


3.   Sample analysis for salinity and dissolved oxygen

3.1. Salinity

Samples for salinity were drawn to 125 ml flasks, stored in a constant 
temperature (20šC ± 1 K) laboratory and analyzed within 20 h to 30 h. 

Standard seawater, batch P120 (K15=0.99985) from Wormley by 06 April 1992, was 
used to standardize the salinometers.  Standardizations were performed before 
analysis started each day.  After 36 bottles, standardization was verified and 
the result noted in a log.  Each sample was rinsed three times before measuring 
and read three times.

Due to stability problems of order 0.003 psu within a series of 36 bottles, 
salinometers were changed:

              Stat                      ID  Stability 36 samples
              ------------------------  --  --------------------
              001 to 010  PORTASAL      A   0.001 psu
              011 to 018  AUTOSAL 8400  B  <0.003 psu
              019 to 119  PORTASAL      A   0.001 psu
              120 to 223  PORTASAL      B  <0.001 psu

Whenever unstable conditions were observed, standard seawater was used and 
salinity linearly corrected for drift.

At four (non-WHP) stations, bottles were closed at same depths to get multiple 
samples for comparison.  The maximum deviations from the means were less 0.003 
psu.  From the following statistics it follows that the precision is better 
0.002 psu.


TEST STATIONS: SALINITY

              Stat  depth  Bottles close  Stand. dev
              ----  -----  -------------  ----------
               27   2000        32          0.0009
               75   4400        26          0.0018
              118   2500        27          0.0011
              190   1000        24          0.0016

Figures 4 and 5 show the results from 275 double samples from pairs of bottles 
taken throughout the cruise from the whole water column.  Of these, 51% differ 
by less than 0.001 psu, and 85% by less than 0.003 psu.  This result is not 
significantly improved when only samples from deeper than 980 dbar are 
considered.


DQE'S COMMENT ON SECTION 3.1

All salinity measurements were done and reported thoroughly.  As the 
comparisons of oxygen measurements (see 3.2 below) from the same test stations 
with significantly improved results from deeper levels show, the relative high 
value in salinity precision seems not to be due to mistakes in sampling but to 
the trouble with drifts in all 3 salinometers, rather.  Nevertheless, from the 
high number of samples one may expect a good calibration the CTD's salinities.


3.2  DISSOLVED OXYGEN

Samples for oxygen were drawn after those for CFCs and helium into flasks of 
120 ml.  Temperature of the sample was measured before rinsing the flask three 
times.  Samples were measured along the guidelines of the WOCE Operations 
Manual in constant temperature (20šC ± 1 K) laboratory.  The method included to 
automatically detect the inflection.

Multiple samples from same depths at three test stations show that a precision 
of 0.01 ml/l is expected.


TEST STATIONS: OXYGEN

              Stat  depth  Bottles close  Stand. dev
              ----  -----  -------------  ----------
               27   2000        32          0.003
               75   4400        26          0.007
              190   1000        24          0.009
              
In figures 6 and 7 the results from 297 double samples from pair of bottles 
throughout the cruise and the water column are displayed.  Of all double 
samples, 39% agree to within 0.005 ml/l, and 70% to within 0.015 ml/l.  This 
result is much improved if one restricts to the 213 samples from depths larger 
than 980 m: then, even 45% agree to within 0.005 ml/l.  For depths larger 2480 
m, the standard deviation is 0.013 ml/l.


DQE'S COMMENT ON SECTION 3.2

As the multiple and the double samples show, oxygen measurements meet the 
requirements of the WHP.


4.   CTD PRESSURE SENSOR CALIBRATION

Both CTD's carried a Paine strain gauge sensor.  These sensors routinely are 
calibrated at IFREMER's calibration center which is certified by the 'Bureau 
National de Metrologie' (BNM).  A dead weight tester made by 'Desgranges et 
Huot' with an accuracy of ± 0.75 dbar at 6000 dbar is used.


4.1. CALIBRATION UNDER LABORATORY CONDITIONS (20°C)

Pre- and post cruise calibrations were made for both CTD's with repeated 
loading (upper panels in fig. 8, 9) and unloading (lower panels) cycles.  Third 
order polynomials have residuals less 2 dbar.


4.2. STATIC TEMPERATURE EFFECTS

Pressure sensor temperature was measured during the profiles.  Laboratory 
calibrations at 7 different temperatures that cover the range are available.  
The effect is less 5 dbar.  The additional corrections are necessary after 
having applied the 20šC basic calibration less than 3 dbar.  The inner sensor 
temperature is modeled for a typical decent and hatched in figure 10.


4.3. DYNAMIC EFFECTS OF TEMPERATURE CHANGES

The dynamic responses to about 20 K temperature shocks were measured in the 
laboratory for both CTD's (fig. 11).  The corrections applied for CTD profiles 
assume a single shock of this order within the thermocline, a lowering speed of 
1m/s, 13 minutes at maximum pressure before the up-profile starts, and a 1 
minute stop to close a bottle.


4.4. CORRECTIONS OF PRESSURE MEASUREMENTS

Taking the 20 C basic 3rd order regressions at the 400 dbar interval 
calibration points, the corrections for the effects of both, static and dynamic 
temperature corrections are added.  For the combined effects, a 5th order 
polynomial regression is applied to all pressure measurements (fig. 12, 13: 
loading mode in upper panels, unloading mode in lower panels).


4.5. VERIFICATIONS AFTER CORRECTIONS

For both CTDs, the differences at the surface before and after the profile 
corresponded well to the overall laboratory calibrations displayed in figures 
12 and 13.

Reversing electronic pressure sensors of SIS were used on the up profile.  Pre- 
and post cruise calibrations were performed at 2.5°C at 7 points between 0 dbar 
and 6000 dbar.  The corrected values of CTD and SIS sensors compare well within 
2 dbar which may be assumed to be the overall accuracy of pressure measurements 
for WHP cruises A6 and A7.


DQE'S COMMENT ON SECTION 4

Both sensors show a major change in their response characteristics at pressures 
larger than 4500 dbar in the post cruise calibration (fig. 8, 9) which appears 
strange to me.  While the pre cruise calibration has the 3rd order polynomial 
response as it is typical for the Paine sensor, the post cruise calibrations 
for both sensors are more or less parabolic.  The effect results in an order 
3.5 dbar change for CTD2521 at 5400 dbar, which is the maximum pressure during 
the cruise; the effect is less for CTD2782.  I wonder if such a change in the 
response characteristics found in other sensor calibrations from this period of 
time in which case they might indicate a shift in reference rather than CTD 
sensors.

Hysteresis may depend on the maximum pressure to which the sensor was exposed 
before unloading, with maximum hysteresis being expected at the high end of the 
range at 6000 dbar.  During these calibrations, the maximum pressure was kept 
to 6000 dbar.  This excludes check of hysteresis effects at lower maximum 
pressures.  However, since hysteresis was less than about 1.5 dbar at all 
pressures this will have a minor effect on the final calibration.

The corrections for static temperature responses could better have been applied 
directly by linear interpolation since the inner temperature was measured, as I 
understand.  However, the effect will be small, anyway.  The same holds for the 
dynamic response. 

All corrections are modeled empirically into one 5th order polynomial for each, 
loading and unloading mode.  As the comparison of corrected CTD pressures with 
corrected SIS pressures shows this method was able to meet the WHP requirements 
for CTD pressure measurements.


5.   CTD TEMPERATURE SENSOR CALIBRATION

The measurements of a high precision Rosemount and that of a fast response NTC 
resistance are combined to standard MKIIIB temperature output at a resolution 
of 5 mK.


5.1. OPERATIONAL MODE

CTD temperature sensors are routinely calibrated at IFREMER before and after a 
cruise.  During calibration, the CTD is completely immersed into the 
temperature stabilized calibration bath.  Temperature readings are compared to 
a reference Rosemount sensor which ITS90 calibration is traced back on a 
regular basis to the BNM.

Both CTDs were in use since 1982 with changes in calibration not exceeding 10 
mK.  While CTD2521 stayed stable during the cruise (fig. 16a), CTD2782 showed a 
clear offset of 2 mK at 0šC and 8 mK at 25šC (fig. 16b).  The uncertainty of 
CTD2782 is 2 mK up to 5šC, and 4 mK for larger temperatures.


5.2. VERIFICATION AFTER CORRECTION

Seven reversing electronic thermometers made by SIS and calibrated, both before 
and after the cruise, were used throughout the cruise.  After the change of 
CTDs between stations 82 and 83, a 'jump' in the difference to all SIS sensors 
is observed (15 mK ± 1 mK) that corresponds well to the difference in the CTD 
laboratory calibration at 2°C (16 mK; see fig. 17 for temperature range 2.5 to 
5°C and fig 18 for the 1°C to 2.5°C range).  Final offsets between SIS and CTD 
are probably due to a pressure effect on the SIS sensors.

For stations 1 to 82, accuracy as derived from figures 17 and 18 is of order 1 
mK, over the whole cruise 2 mK.


DQE'S COMMENT ON SECTION 5

From the calibration curve of CTD2521, its uncertainty seems to be of the order 
of 1 mK.  As for CTD2782, it might be interesting to search for similar 'jumps' 
in earlier calibrations. 

Accuracy of CTD temperatures as estimated from pre- and post cruise 
calibrations, and from comparisons with the seven SIS thermometers seems better 
than 2 mK, thus meeting WHP requirements.


6.   CTD CONDUCTIVITY SENSOR IN-SITU CALIBRATION

6.1. OPERATIONAL MODE

The conductivity sensor output is averaged while bottles are closed.  This 
average is subject to the cell's pressure and temperature correction.  The 
result is compared to in-situ conductivity values as derived from bottle 
salinities.  A first order linear polynomial regression is calculated for 
stations or groups of stations:

                               COR=C0 + C1*COS

Outliers are removed until all differences are within 2.8*STDEV, STDEV being 
the standard deviation.


6.2. STATION GROUPING

CTD2782 stayed rather stable for large groups of stations.  CTD2521, however, 
needed a station by station calibration from station 57 on until its exchange 
after station 82.  Since the linear coefficient C1 did not change when 
calculated for stations 1 to 56 or station 1 to 77, the change in calibration 
was totally due to the offset C0.  Thus, taking C1 as fixed, C0 was adjusted 
for station 57 to 77.  For stations 78 (after the call of port) to 82, both 
coefficients were calculated station by station.  See table III-1 for a 
complete listing of coefficients.


6.3. OVERVIEW PROFILE CALIBRATION

With the 5580 samples (89%) used for the calibration (see fig. 19, 20 for 
conductivity; fig. 21 for salinity), the overall standard deviation of the 
residuals is 0.0023 mS/cm.  Only station group 204 to 219 is slightly worse 
(0.0029 mS/cm).  Overall the cells' in-situ calibrations are close to WHP 
standards.


6.4. VERIFICATION

Stations 31 and 119 were repeated with a different CTD at stations 223 and 156, 
respectively. Also, positions of stations 211 and 145 are close to SAVE station 
45 and TTO station 63, respectively.  All 4 theta-S diagrams coincide well in 
the deep sea with salinity deviations of just 0.001 psu. 


DQE'S COMMENT ON SECTION 6

The method applied to determine the calibration coefficients is well 
established.  Comparison in theta-S space of two 'cross stations' of this 
cruise and two 'cross stations' with stations from SAVE and TTO establish an 
accuracy in salinity close to 0.001 psu meeting WHP standards.


7.   CTD DISSOLVED OXYGEN SENSOR IN-SITU CALIBRATION

7.1. OPERATIONAL MODES

The calibration of the oxygen sensor followed the method described first by 
Millard (1982, see GC1 for the complete reference).  The formula models the 
effects of temperature, inner and outer temperature difference and pressure, 
and salinity through the saturation formula by Krause (1984, see CG1 for the 
complete reference) on the electrical current (OC) that is measured in the 
cell.  Compared are averages of OC over a 15 dbar interval from those depths of 
the lowering profile where sample oxygen were measured.  The calibration 
coefficients are determined for groups of stations.


7.2. UNITS OF DISSOLVED OXYGEN

The calibration is performed and reported in units of ml/l.  All units are 
converted then to µmol/Kg keeping those values in ml/l.


7.3. STATION GROUPING
Three sensors were used:

                        Stat.    CTD   Oxygen sensor
                        -------  ----  -------------
                        001-069  2521  A
                        070-082  2521  B
                        083-223  2782  C
                        

Sensor A, in addition to Millard's regression needed a 5th order polynomial 
regression in pressure.  Sensor B needed a calibration by stations.  Only 
sensor C was stable over large parts.  See Tables III-2 and III-3 for 
coefficients and details.


7.4. OVERVIEW OF PROFILE CALIBRATION

The results are presented in figures 24 and 25.  A total of 6052 samples 
(93.7%) were used in the calibration procedure.  Of these 42.4% have residuals 
less 0.025 ml/l, and 83.9% less 0.075 ml/l with a standard deviation of 0.066 
ml/l.  Disregarding samples from depths less 980 dbar, this result improves to 
49.8% and 92.2%, respectively and a standard deviation of 0.041.  The subset of 
stations 70 to 223 has an overall (all depths) standard deviation of 0.046 
ml/l.


7.5. VERIFICATION

One station pair (Stat. 119, 156) from this cruise with different sensors, and 
two SAVE stations can be compared (fig. 26, 27).  The obvious differences 
between stations 119 and 156 also show up in other chemical parameters, and 
thus probably are due to a change in deep water masses at that position during 
the cruise.

Stations 218 and 130 compare well with SAVE station 158 and TTO station 25.


DQE'S COMMENT ON SECTION 7

The formula used to model the oxygen sensor response did not account for the 
sensor's speed through the water as requested in a later version in the WHP 
Operations and Methods Handbook.  Nevertheless, the standard deviations 
reported for the residuals of the sensor calibration meet well the WHP 
requirements.



PART B.  CTD DATA EVALUATION


8.  BASICS

A6 and A7 data available at the WHP-O were:

~.SUM file
~.WCT CTD data
~.HY2 bottle data

and additional two meridional sections linking A6 and A7.

CTD data were on 1 dbar intervals. WHP requirements are 2 dbar intervals; the 
higher vertical resolution has led to problems with computer (PC) storage and 
computing time using the programs kindly provided by R. Millard, WHOI.

CTDTMP and CTDSAL in the CTD files are reported with 4 decimal places, however 
with tailoring zeros.  This is not WHP standard.  Also, the quality byte for 
oxygen was set to zero throughout the CTD-files.

Although the overall quality of the data set is expected to meet WHP standards, 
the remarks above and the quick evaluation below will show that some revision 
of the data needs to be made.  I therefore restrict to the (more problematic 
section A7 plus some meridional stations (Stat. 1 - 99); nevertheless, all 
recommendations made below also hold for A6.

The set of DQE programs allows to compare the CTD files with the CTD values in 
the bottle file. Only data flagged as 'good' were used.  The following checks 
including some blow-up figures (not always shown) were made:

~ theta-CTDSAL, overall in the east and in the west
~ theta-CTDOXY, overall in the east and in the west
~ deviations CTDSAL and SALNTY on pressure levels by station
~ deviations CTDOXY(downcast) and OXYGEN on pressure levels by stations
~ same by pressure in station groups (waterfall plots)
~ noise level in the deep ocean
~ static stability in profiles


9.    THETA-CTDSAL, THETA-SALNTY 

These plots are grouped for Stat. 1-50, and 41 -91.  For stations 1 - 50 in the 
eastern basin, the overall plot (*Fig. 28a) shows extremely low salinities at 
the surface as a result of the Congo River plume.  At least two non-flagged 
CTDSAL outliers from the upcast at the high end are detectable (and marked in 
*fig. 28a).  Others are identified at lower temperatures (*Fig. 28b).  In the 
deep ocean (*Fig. 28c), some SALNTY values are aside the bunch.  An example 
(*Fig 28c) shows that large deviations between samples and the CTD are observed 
at Stat. 9.  This station needs to be compared directly with neighboring 
stations for the salinity calibration.  A more careful check will later 
identify other stations with calibration offsets.

In *Fig. 29a to 29c the same is repeated for Stat. 41 to 91. Again, some few 
outliers of SALNTY are identified in the deep ocean.

Overall, flags need to be checked.


10.   THETA-OXYGEN

Station groups 1 to 51 (*Fig. 30a-c) and 41 to 91 (*Fig. 31 a-c), both show 
some extreme non-flagged spikes (Stat. 7, Stat. 38) in CTDOXY and some bad non-
flagged values in the samples.  Also, some CTDOXY profiles look rather noisy.  
Overall, flags need to be set/checked.


11.   RESIDUALS IN CALIBRATION

11.1. CTDSAL

In *figure 32a these differences are plotted as single dots by STNNBR for all 
depths (upper panel), for depths larger 1000 dbar (middle) and by pressure 
(lower panel).  Also included are the mean differences for each station (bold 
line).  *Fig. 32b gives a blow-up of the upper and lower panels of *Fig. 32a.  
Some non-flagged outliers are marked. 

The marked minima and the maxima of the bold line in the *Fig. 32a (middle 
panel) identify those stations, where the differences between CTDSAL and SALNTY 
need a check of the CTDSAL calibration by comparing neighboring deep CTD 
stations: This is recommended for the following stations: 009, 010, 023, 033, 
035, 048, 076, 077, 078.

A more severe problem is obvious from *Fig. 32b: It shows a bias in CTDSAL 
calibration at pressures higher than 4000 dbar.  Perhaps, the pressure 
compensation that has been applied is not sufficient.  To my experience, these 
sensors may need additional corrections to the linear one applied to the 
compensated raw data.

While *Fig. 32 allows one to identify stations with suspicious overall 
calibration, the waterfall plots in *Fig. 33a to 33i give insight to the 
residuals' distribution over single profiles.  Although the resolution is 
sparse, some stations can be identified to have a systematic bias against the 
samples on that station.  This holds for almost all stations which have samples 
from depths larger than 4000 dbar (as seen already in *Fig. 32).  In *Fig. 33a 
and 33b, the subset shallow stations may have calibration problems: stations 
005, 006, 010 and 097.


11.2. CTDOXY

In *Figure 34, the residuals between the CTD downcast and the sample oxygen are 
shown.  Some non-flagged outliers are marked (*Fig. 34a).  With better 
resolution, *Fig. 34b (middle) shows the station mean residuals well within ± 5 
µMol/Kg for pressures > 1000 dbar.  Problems may occur at the beginning (Sta. 
6), and only a few other stations.  I recommend comparison of neighboring 
stations in the deep ocean: 57, 58, 88, 95 and maybe 86.  Station 6 is shallow 
and may checked against station 008.

In the waterfall plots of *Fig. 35 those stations are marked that over wider 
parts of a profile show a bias in the residuals.  At these stations, the CTDOXY 
should be compared to neighboring stations to verify the calibration.


12.   NOISE LEVEL IN CTD PROFILES

Since the data are provided on a 1-dbar interval rather than on 2-dbar 
intervals, the noise level maybe expected higher than usual for 2-dbar WOCE 
data.  The method calculates means and rms over 2 - 12 dbar high pass filtered 
data. 

For the deep ocean (*Fig. 36a), the rms of CTDSAL is well below 0.001 psu 
(upper panel), that of CTDOXY generally below 0.5 µMol/Kg (middle panel).  The 
mean rms for salinity is 0.0004 psu is slightly higher than for other WOCE 
cruises with low values in the deep eastern basin (stations 10 to 50) and high 
values between station 55 and 86 reflecting more variability in the deep 
western basin. 

The station averaged rms for oxygen (0.24 µMol/Kg is twice as high as the so 
far best WOCE cruises show probably reflecting the fact that the sensor's speed 
through the water column was not taken into account during the calibration.  
Some stations (around 20, 43, 51, and 75) peak in scatter and may be re-
examined.


PART C.  RECOMMENDATIONS

Resubmit the data set subject to:

**  check for the calibration procedure of CTDSAL for high pressures
**  incorporate the oxygen sensor's speed through the water column into the 
    calibration to improve the noise level.
**  deliver downcasts at:
    2 dbar intervals
    4 digit places for CTDTMP, CTDSAL, SALNTY (no zeros tailoring)
**  set flags for CTDOXY
**  carefully check all flags for SALNTY, CTDSAL, CTDOXY; setting flags may 
    make use of the known standard deviations for the calibration.

I'm prepared to inspect the complete data set when resubmitted.


ACKNOWLEDGEMENTS

The WHP-O at WHOI again has been a friendly and effective host. Software used 
for part B of this evaluation, was kindly made available by Bob Millard; 
special thanks to him for his helpful guidance. This work was supported by the 
Bundesminister für Bildung und Wissenschaft, Bonn, Germany, under grant WOCE 
IV.


REFERENCES

Le Groupe CITHER-1: Campagne CITHER-1 N/O L'ATALANTE (2 janvier-19 mars 1993). 
    Recueil de donnees, Vol 2: CTD-O2. Rap. Interne LPO 94-04, Laboratoire de 
    Physique des Oceans, IFREMER, Brest, France, 1994.

Millard, R.R. and K.E. Yang. CTD calibration and processing methods used at 
    WHOI. WHOI Techn. Rep. 93-44, 1993


For further references see Le Groupe CITHER-1 (1994), there especially Billant 
(1985) for CTD calibration methods as applied at IFREMER; Billant (1990) for 
SIS pressure meter characteristics; Millard (1982) for the calibration of the 
oxygen sensor.


TABLE III-1

Bilan de la calibration des profils de conductivité de la campagne CITHER 1

Sonde 	Station Nombre 		Nombre 		Déviation 	Coefficients
utilisée ou	d'échantillons 	d'échantillons 	Standard 		
	groupe	considérés	retenus par	(0-6000)	C1	  C0
				le calcu			
------------------------------------------------------------------------------
2521	1=>56	1367		1187		0.0024		0.999357  0.0320
	57	32		28				"	  0.0290
	58	32		29				"	  0.0227
	59	32		28				"	  0.0233
	60	32		27				"	  0.0239
	61	32		29				"	  0.0245
	62	32		31				"	  0.0252
	63	32		28				"	  0.0258
	64	32		29				"	  0.0264
	65	32		27				"	  0.0270
	66	32		29				"	  0.0277
	67	32		30				"	  0.0283
	68	32		30				"	  0.0271
	69	32		26				"	  0.0277
	70	32		28				"	  0.0284
	71	32		31				"	  0.0290
	72	32		28				"	  0.0296
	73	32		30				"	  0.0302
	74	32		30				"	  0.0309
2782	75	32		32		0.0017		0.999022  0.0423
2521	76	32		30				0.999357  0.0303
	77	32		27				"	  0.0310
	78	32		19				0.999492  0.0415
	79	32		29		0.0024		0.999716  0.0258
	80	32		30		0.0021		0.999520  0.0332
	81	32		29		0.0021		0.999382  0.0323
	82	32		29		0.0019		0.999096  0.0405
2782	83=>91	237		211		0.0022		0.999781  0.0063
	92=>118	769		686		0.0021		0.999695  0.0072
2521	119	32		29		0.0013		0.999862  0.0379
2782	120=>203 2425		2164		0.0021		0.999589  0.0112
	204=>219 479		442		0.0029		0.999545  0.0106
	220=>223 128		117		0.0020		0.999687  0.0106

TABLE III-2

Bilan de la calibration des profils d'oxygène dissous de la campagne CITHER 1

Capteur	Station	Nombre		Nombre		Déviation Standard		Coefficients
utilisé	ou	d'échantillons	d'échantillons	0-6000	0-1000	1000-	SOC	OXPC	 OXTC	  OXC2	
	groupe	considérés	retenus par			6000					
				le calcul								
-------------------------------------------------------------------------------------------------------------------
Capteur 1=>11	189		184		0.179	0.244	0.053	0.0356	0.000193 -0.0169  3.552	Correction
A	12	30		30		0.103	0.165	0.044	0.0394	0.000165 -0.0334  0.769	supplé-
	13	30		30		0.093	0.185	0.045	0.0404	0.000153 -0.0246  1.511	mentaire
	14	31		31		0.095	0.156	0.038	0.0398	0.000163 -0.0227  1.497	par 
	15	31		31		0.098	0.209	0.035	0.0409	0.000149 -0.0252  1677	polynome 
	16	32		32		0.131	0.240	0.029	0.0403	0.000155 -0.0260  1.553	de degré
	17=>21	160		143		0.061	0.120	0.045	0.0468	0.000122 -0.0348  2.678	5
	22	32		32		0.076	0.135	0.027	0.0408	0.000154 -0.0239  1.791	
	23	29		29		0.059	0.103	0.032	0.0425	0.000147 -0.0261  1.311	
	24	32		31		0.054	0.088	0.023	0.0404	0.000162 -0.0237  1.420	
	25	31		31		0.037	0.070	0.025	0.0444	0.000141 -0.0285  1.341	
	26et27	35		34		0.063	0.111	0.030	0.0422	0.000155 -0.0256  1.347	
	28=>67	1251		1216		0.082	0.127	0.046	0.0430	0.000149 -0.0267  1.402	
	68*	32		27		0.102	0.148	0.118	0.0430	0.000128 -0.0270  1.210	
	69*	32		31		0.049	0.064	0.046	0.0440	0.000137 -0.0272  0.972	
Capteur 70	32		32		0.062	0.111	0.043	0.0658	0.000138 -0.0348  0.596	
B	71	32		31		0.051	0.087	0.041	0.0712	0.000131 -0.0335  0.933	
	72	32		30		0.065	0.113	0.053	0.0750	0.000125 -0.0349  1.111	
	73	32		31		0.047	0.047	0.047	0.0732	0.000131 -0.0343  0.820	
	74	32		32		0.036	0.042	0.035	0.0712	0.000139 -0.0328  1.102	
	75**	32		29								

	* Les profils 68 et 69 sont partiellement inexploitables.
	** Le profil 75 est totalement inexploitable

TABLE III - 3

Bilan de la calibration des profils d'oxyène dissous de la campagne CITHER I


Capteur	Station	Nombre		Nombre		Déviation Standard		Coefficients
utilisé	ou	d'échantillons	d'échantillons	0-6000	0-1000	1000-	SOC	OXPC	 OXTC	  OXC2
	groupe	considérés	retenus par			6000				
				le calcul							
---------------------------------------------------------------------------------------------------------
Capteur 76	32		31		0.037	0.043	0.037	0.0683	0.000143 -0.0326  0.799
B	77	32		31		0.031	0.033	0.031	0.0698	0.000142 -0.0341  0.657
	78	32		32		0.066	0.077	0.063	0.0698	0.000140 -0.0331  0.938
	79	32		32		0.044	0.080	0.029	0.0689	0.000144 -0.0328  0.687
	80	32		29		0.016	0.008	0.018	0.0694	0.000144 -0.0331  0.521
	81	32		29		0.048	0.043	0.050	0.0703	0.000142 -0.0333  0.817
	82	32		32		0.052	0.082	0.042	0.0707	0.000143 -0.0345  0.753
Capteur 83=>91	236		221		0.059	0.086	0.043	0.0566	0.000148 -0.0307  0.563
C	92=>118	769		717		0.054	0.074	0.044	0.0559	0.000149 -0.0295  0.658
Capteur 119	32		31		0.046	0.083	0.027	0.0679	0.000157 -0.0316  0.698
B 
Capteur 120=>203 2423		2213		0.045	0.058	0.040	0.0562	0.000147 -0.0304  0.609
C	204=>223 607		557		0.037	0.048	0.033	0.0551	0.000149 -0.0294  0.642







COMMENTS ON THE DQE RECOMMENDATIONS FOR THE CTD-O2 DATA OF WHP LINES A6 AND A7
(M. Arhan, A. Billant)

The DQE considered the data as meeting the WHP standard, yet made several 
recommendations (Part C of the report).

~ Check for the calibration procedure of CTDSAL for high pressures. We have 
  checked the calibration procedure: It is the one recommended in the WHP 
  operations manual, and described in the UNESCO Technical Paper in Marine 
  Science nb 54 (1988).  When using this procedure, some depth-dependency of the 
  residuals at high pressures (> 5000 dbar) cannot be avoided (as an example, 
  see figure 3.8 of the UNESCO report) at least in certain oceanic area.

~ Oxygen sensor speed: No accurate measurement of the time was available on that 
  cruise, for which the in situ reference parameter was pressure.  We usually 
  remove the heave effect from the oxygen profiles by a ~10 dbar running mean.

~ Four digit places for CTDTMP, CTDSAL, SALNTY: As said in the cover letter, we 
  can create new exchange files at this format if you judge it necessary.

~ Set flags for CTDOXY: These are oxygen values from the down-profiles, averaged 
  over a 15 dbar pressure range centered at the pressures of bottle triggering. 
  These values are compared with the water sample data and, in case of a 
  discrepancy exceeding 2.8 standard deviation, we choose to flag the bottle 
  value, not the CTD one.  This is a matter of convention, and the DQE is right 
  in pointing out that, in some cases, the high difference is caused by 
  inaccurate CTD values.  As these CTDOXY values are only used for the 
  calibration, we did not judge it necessary to examine the problematic cases to 
  decide which parameter should be flagged.  Had we done it, the choice could 
  only have been subjective in most cases.
  
~ Carefully check all flags for SALNTY, CTDSAL, CTDOXY.  (See the set of figures 
  with the problematic points marked).  In several property-property plots (e.g. 
  28b, c, d), some points are found slightly aside of the main << cloud of 
  points >>, although the difference << CTD minus water sample >> was less than 
  2.8 standard deviations, and the values were therefore not flagged.  Again, 
  this is a matter of convention.

In several other plots (e.g. 30a, 31a, 32a, 33, 34a), differences CTD-water 
sample were reported, although the water sample data were flagged to either 5 or 
3.  This leads to apparent problems (only apparent, because the data were 
flagged).  For instance, the value -9 was set when there was no data, with a 
flag of 5 (absence of data) in the WS files.  Taking into account the value -9 
leads to several differences at ~44 (~35 -(-9)) in figure 32a, or ~209 (= 200 -
(-9)) on figure 34a.  The same cause leads to horizontal lines on the 
<<waterfall plots>>, and to points aside of the <<main cloud>> in the property-
property plots.  In particular, although CTDOXY was not measured at station 75 
(all flags at 5) and was only partially present at stations 68, 69 (sensor 
problems), erroneous points for these stations are reported on figure 34a.





WHPO DATA PROCESSING NOTES


A06
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
03/01/96  Oudot          BTL/CFCs       Submitted for DQE
    
03/28/96  Oudot          Carbon Data    Submitted for DQE
          TCARBN, CHLA, ALKALI, FCO2 (pCO2), PH
    
07/09/96  Mueller        CTD            Agreed to do DQE
    
07/09/96  Koltermann     NUTs/S/O       Agreed to do DQE
    
09/18/96  Koltermann     NUTs/S/O       Sent data to DQE
    
10/03/96  Mueller        CTD            DQE Report submitted
    
03/14/97  Arhan          CTD            DQE Complete  DQE Report sent to PI
    
01/22/98  Oudot          Tracer         Submitted for DQE
          asking for est. time of DQE completion
    
02/10/98  Arhan          CTD            DQE Issues Resolved
          "Following my previous letter of November 13, 1997, this one is to 
          confirm that we are releasing the CTD-O2 data of the WHP sections A6 
          and A7 to the public domain". 
    
07/06/98  Oudot          BTL            PI OK'd Pub Release; Data still w/ DQE
    
12/03/98  Guinehut       CTD/BTL        Pressures updated on website 
          * S/O2, NUTs, CFCs, CTD Pressures are not always in ascending order. 
          * The pressure 2220. is everywhere replaced by the pressure 2222..
          * The CTD data are not reported in a uniform pressure series in order 
            of incresing pressure with a pressure resolution of 2 dbar. 
          * The CTD data have a pressure resolution 2 dbar in some files and of 
            1 dbar with large gaps with no data in most of files. For example, 
            in the file CTH10123.WCT there are no data between 78. and 82. dbar 
            and between others pression on depth. 
    

A06
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
01/13/99  Jean-Baptiste  HE/TR          Ready to submit
    
02/09/99  Koltermann     NUTs/S/O       DQE Report Requested by js
    
02/10/99  Koltermann     NUTs/S/O       DQE not begun
          I agreed (to do the dqe) but never was able to get the software of 
          Terry's to work. I told him and still we never succeeded. So at one 
          time I had counted myself out. I am not sure how go from there. At 
          that time I had time and interest, but that faded away when it didn't 
          work. I might reconsider if things are easier now and Viktor might 
          help on my end of things.
    
02/10/99  Oudot          DOC            Report at WOCE is correct
    
03/11/99  Jean-Baptiste  He/Tr          Submitted for DQE
    
04/20/99  Kappa          DOC            PDF DOC assembled
          contents: 
            * a06-7_ctd.dqe.pdf
            * a06-7.pdf
            * a06-7_ctd.dqe.pdf
            * a06_ctd.readme.pdf
            * a06-7.pdf
            * a06-7_ctd.dqe.pdf
            * a06_ctd.readme.pdf
    
04/30/99  Kappa          DOC            PDF Directory Updated
          added: 
            * a06-7_notes.pdf, 
            * a06_cruzpln.pdf, 
            * a07_cruzpln.pdf 
    
10/13/99  Bartolacci     SUM            Update needed; files incomplete
          sumfiles for A6 and A7 are incomplete.  They were split from one large 
          file, and are currently missing stations.  I have put the original 
          all-inclusive sumfile in my incoming ftp area under A6A7 subdirectory 
          along with a readme file.  The sumfiles need to be re-created from the 
          original.
    
10/14/99  Bartolacci     SUM            Data Update
          I have replaced the old incomplete sumfiles with the newly split and 
          reformatted versions, thanks to Sarilee.  I have also regenerated the 
          station plots for both lines to include the additional stations, and 
          have updated the table to reflect the change in sumfiles. 
    

A06
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
10/14/99  Anderson       SUM            Data Update
          I have reformatted and separated A06 and A07 into individual .sum 
            files, leaving in the stations that were previously missing.
          The files are in my ftp area on whpo in subdirectory A06A07.
    
11/11/99  Alfultis       SUM            Data Update
          Two stations appear ro have incorrect longitudes - 
            * station 51 has a longitude of 13 59.90 E and 
            * station 72 has a longitude of 26 29.97 E while 
          all the surrounding stations have Western Longitudes.
    
02/29/00  Huynh          DOC            pdf updated, txt added to website
    
03/08/00  Diggs          CTD/BTL        Data Update
          I have separated 35A3CITHER1(1/2) which is A06/A07.  The CTD and HYD 
            files now have different files which reflect the contents of the SUM 
            file.  All tables and HTML files have been updated as well.
          In addition, I have corrected the EXPOCODES in all of the CTD and 
            hydro files.
    
09/19/00  Huynh          DOC            Website Updated w/ CTDOXY dqe report
          CTD/OXY dqe for A06 and A07 added to doc files
    
12/11/00  Uribe          DOC            Partial text doc submitted; put online
          Files, received 1997 AUG 15, were found in incoming directory under 
            whp_reports. This directory was zipped, files were separated and 
            placed under proper cruise. All of them were labled as sum files. 
          These are CRUISE SUMMARIES and NOT sumfiles.
    
06/20/01  Uribe          BTL            Website Updated; EXCHANGE File Added
          Bottle file in exchange format has been linked to website.
    
06/21/01  Uribe          CTD/BTL        File modified/added
          The exchange bottle file name in directory and index file was modified 
            to lower case.
          CTD exchange files were put online.
    


A06
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
12/21/01  Hajrasuliha    CTD            Internal DQE completed
          created *check.txt file for the cruise.  created .ps files.
    
12/21/01  Uribe          CTD            EXCHANGE File Modified
          CTD exchange files were slightly modified. The stations that were 
          missing the SECT ID were given a name according to the cruise name. 
          CITHER1L2; standing for CITHER 1, leg 2. This naming convention will 
          be a standard for sumfiles missing the SECT ID.
    
12/21/01  Uribe          CTD            EXCHANGE File Added
          CTD has been converted to exchange using the new code and put online. 
          The bottom half of the sumfile is missing the WOCE SECT ID. This was 
          causing a problem with the exchange code. For the purpose of the 
          conversion the column was filled in with A06.
    
06/19/02  Klein          NEON/He/Tr     Submitted with updated QUALT 2 words
          The whpo file was basically fine, but compared to our file 22 tritium 
          values and 56 neon values were missing. I therefore included the 
          tritium and neon values in the file I am sending you. The quality 
          flags in byte 2 are updated for the tracers. CFC data are from the 
          french, they were notified about changes in quality flags.
    
08/16/02  Diggs          CFCs/HE/TR     Update Needed
          Here's what Birgit had to say about these data (A06):
          * The bottle data files we used and the one at your side are 
            identical. 
          * The CFC data (F11,F12) are from a french group, we have notified 
            them for minor changes we made to the quality flags. 
          * The quality byte 2 now contains the revised quality flags for f11 
            and f12. 
          * We also controlled the tritium and helium data set for this cruise. 
            But it seems they have not been submitted to you yet. I will write 
            to Jean-Baptiste and ask him, if he wants to submit the data. 
          * The helium data for this cruise turned out to be very poor quality 
            and we have flaged them 3 for the entire data set anyway.
    
08/19/02  Anderson       HE/TR          WebsData merged into online file
          DELHE3, HELIUM, and TRITIUM was merged into the online file by Sharon 
          Escher. Made new exchange file. 

          Merge notes:
          * Started with a06/original/TRACERS_19990311/WOCE_A6A7.dat and in a06 
            & a07 (in original) under 2002_KLEIN A6hy.txt & A7hy.txt
          * Merged ( using mrgsea ) delhe3, helium, and tritum into EACH of the 
            existing files A6hy.txt and A7hy.txt sent by Birgit Klein that 
          contained the changes in the quality flags mentioned in e-mail.


A07    
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
10/14/99  Anderson       SUM            Data Update
          * Record 284, sta. 93 had the time as 15 8, changed to 1508.
          * Record 298 sta. 97 had the date as 200193 changed to 020193. 
          * Stations 63 and 64 at CODE BO had E longitude, changed to W to 
            conform with the other longitudes. 
    
11/16/99  Bartolacci     SUM            Data Update, corrected .sum file
          As per Dave's notes below, I have corrected the A07 sumfile, time/date 
          stamped it and placed it back out on the web.  As far as I know, these 
          two errors in hemisphere were the only things in question
    
11/16/99  Muus           SUM            Data Update
          The A07 summary file problem brought to our attention by the US Coast  
          Guard Academy is two typographic errors in the original French data:
          * Stations 51 and 72 EN longitudes should be "W" instead of "E".
          * The BE and BO longitudes for these stations are correct ("W").
          * The web site should be corrected and this could be added to any 
            errata that may be planned for CDROMs.
     
06/20/01  Uribe          BTL            Website Updated; EXCHANGE File online
          Bottle file in exchange format has been linked to website.
    
06/21/01  Uribe          CTD/BTL        EXCHANGE Files added/modified/online:
          * The exchange bottle file name in directory and index file was 
            modified to lower case.
          * CTD exchange files were put online.
    
07/19/01  Thurnherr      CTD            Update Needed  pressure values incorrect
          I have noticed that the CTD files of the WOCE A07 section have 
          erroneous pressure values of 2222dbar instead of 2220dbar. E.g. 
          station 007 contains the following records

          press   temp   salnty    oxy    nobs  qual
          ------  ------ -------   -----  ----  ----
          2219.0  3.2740 34.9430   244.3   1    2222
          2222.0  3.2730 34.9430   244.2   1    2222
          2221.0  3.2710 34.9430   244.2   1    2222
          2222.0  3.2680 34.9420   244.5   1    2222
          2223.0  3.2650 34.9420   244.7   1    2222

          All stations therefore have double records at 2222dbar with the 
          exception of the following list
             000 002 004 006 037 075 081 091 093 
             001 003 005 027 054 079 090 092 115
          Both the original and the the exchange format are affected.
    

A07
    
DATE      CONTACT        DATA TYPE      DATA STATUS SUMMARY
--------  -------------  -------------  --------------------------------------
09/05/01  Uribe          CTD            Update Needed  files have bad OXY values
          Email from Andreas Thurnherr indicates 5 CTD files of the WOCE A07 
          section have ranges of erroneous oxygen values. In those files 
          (stations 000, 007, 068, 069, 075) some or all oxygen data appear to 
          be replaced by (rounded) temperature data. Both the original and the 
          exchange formats are affected. This problem has not been ad-dressed at 
          this time. 
    
12/21/01  Hajrasuliha    CTD            Internal DQE completed
          created *check.txt file for the cruise. create .ps files.
    
12/21/01  Uribe          CTD            Website Updated; EXCHANGE File Added
          CTD has been converted to exchange using the new code and put online.
    
08/16/02  Diggs          CFCs/HE/TR     Update Needed
          Here's what Birgit had to say about these data: 
          a7: the same comments as for a6. 
    
08/19/02  Anderson       He/TR          Data merged into online file
          The DELHE3, HELIUM, and TRITIUM were merged into the file with the Q2 
          flage for CFCs sent by Birgit Klein re Steve's e-mail. Made new 
          exchange file. Sent notes to Jerry.

08/19/02  Anderson       HE/TR          Merge notes
    
04/11/03  Kappa          DOC            PDF & Text files updated
          PDF docs:   A06 and A07 Station Plots combined into one map
          * PDF & Text docs:  First Page Data Summaries for A06 and A07 were 
            previously combined.  Now expocodes, chief scientists, cruise dates, 
            ports of call, geographic boundaries are specified by line.
          * Cruise goals added 



